CN116935776A

CN116935776A - Electronic equipment

Info

Publication number: CN116935776A
Application number: CN202210320599.1A
Authority: CN
Inventors: 王勇; 曾慧坤; 彭康; 李玮楠
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2023-10-24

Abstract

The application relates to the technical field of electronics, in particular to electronic equipment. The electronic device includes: a controller for generating a control signal; the driving circuit outputs square wave alternating current signals according to the control signals generated by the controller; the electroluminescent device is used for emitting light according to the square wave alternating current signal output by the driving circuit, the brightness of the light emitted by the electroluminescent device is determined by the high electric signal value of the square wave alternating current signal, and the color of the light emitted by the electroluminescent device is determined by the frequency of the square wave alternating current signal. Therefore, the electronic equipment can drive the electroluminescent device through the square wave alternating current signal, but not the sine wave alternating current signal, so that the electric energy consumed by the electroluminescent device can be saved, and the cruising ability of the electronic equipment is improved.

Description

Electronic equipment

Technical Field

The application relates to the technical field of electronics, in particular to electronic equipment.

Background

An Electroluminescent (EL) device is a device that directly converts electric energy into light energy, has high electro-optical efficiency, and is widely used in a light emitting unit of an electronic device, such as a display unit in a wearable device such as a smart watch, a smart bracelet, and the like. The EL device is typically driven by a high-frequency alternating current signal (frequency is typically hundreds to thousands of hertz), and the driving circuit of the EL device can change the light emission luminance of the EL device by applying alternating current signals of different peaks to the EL device, and can change the light emission color of the EL device by applying alternating current signals of different frequencies.

However, display units, such as display units employing EL devices, generally consume a large amount of electrical energy from electronic devices. With the increase of the requirements of users on the cruising ability of electronic devices, especially wearable devices, how to reduce the energy consumption of a display unit using an EL device, so as to improve the cruising ability of the electronic devices, is a problem to be solved.

Disclosure of Invention

In view of the above, the embodiment of the application provides an electronic device, which drives an electroluminescent device through square-wave alternating current signals, thereby being beneficial to reducing the electric energy consumed by the electroluminescent device and improving the endurance of the electronic device.

In a first aspect, an embodiment of the present application provides an electronic device, including: a controller for generating a control signal;

the driving circuit outputs square wave alternating current signals according to the control signals generated by the controller; the electroluminescent device is used for emitting light according to the square wave alternating current signal output by the driving circuit, the brightness of the light emitted by the electroluminescent device is determined by the high electric signal value of the square wave alternating current signal, and the color of the light emitted by the electroluminescent device is determined by the frequency of the square wave alternating current signal.

In the embodiment of the application, the electronic equipment drives the electroluminescent device through the square wave alternating current signal, so that the electric energy consumed by the electroluminescent device can be reduced, and the endurance of the electronic equipment is improved. And, the luminous brightness of the electroluminescent device can be adjusted by adjusting the high electric signal value of the square wave alternating current electric signal (for example, the high level of the square wave alternating current voltage signal), and the luminous color of the electroluminescent device can be adjusted by adjusting the frequency of the square wave alternating current electric signal.

In a possible implementation of the first aspect, the high and low electrical signal values of the square wave ac electrical signal and the frequency of the square wave ac electrical signal are determined based on a control signal.

In the embodiment of the application, the electronic device can adjust the high electric signal value and the low electric signal value of the square wave alternating current electric signal and the frequency of the square wave alternating current electric signal through the control signal, so as to adjust the luminous brightness and the color of the electroluminescent device.

In a possible implementation of the first aspect, the control signal includes a voltage control signal, and the driving circuit includes: the first tuning circuit is used for receiving the voltage control signal and outputting first tuning signals with different duty ratios according to the voltage control signal; and the boosting circuit is used for boosting the first voltage input into the boosting circuit into the second voltage according to the duty ratio of the first tuning signal, wherein the second voltage is increased along with the increase of the duty ratio of the first tuning signal, and the high electric signal of the square wave alternating current electric signal is identical with the second voltage.

In an embodiment of the present application, the electronic device adjusts the second voltage (e.g., V hereinafter) by adjusting the duty cycle of the voltage control signal _C ) Thereby adjusting the high electric signal value of the square wave alternating current signal and further adjusting the luminous brightness of the electroluminescent device.

In a possible implementation of the first aspect, the control signal further includes a waveform control signal, and the driving circuit further includes: the second tuning circuit is used for receiving the waveform control signal and outputting second tuning signals with different frequencies according to the waveform control signal; the full-bridge driving circuit is used for receiving the second tuning signal and the second voltage, outputting a square wave alternating current signal according to the frequency and the duty ratio of the second tuning signal, wherein the frequency of the square wave alternating current signal is the same as the frequency of the second tuning signal, the duty ratio of the square wave alternating current signal is the same as the duty ratio of the second tuning signal, the high electric signal value of the square wave alternating current signal is the second voltage, and the low electric signal value is the inverse voltage of the second voltage.

In the embodiment of the application, the electronic equipment adjusts the frequency of the square wave alternating current signal by adjusting the frequency of the waveform control signal, so as to adjust the luminous color of the electroluminescent device.

In one possible implementation of the first aspect, the full-bridge driving circuit outputs a second voltage when the second tuning signal is a high electrical signal, and outputs an inverted voltage of the second voltage when the second tuning signal is a low electrical signal; or outputting the second voltage when the second tuning signal is a low electrical signal, and outputting an inverted voltage of the second voltage when the second tuning signal is a high electrical signal.

In a possible implementation manner of the first aspect, the first tuning circuit includes: a first inverter, a second inverter, a third inverter, and a first capacitor; the input end of the first inverter is connected with the output end of the third inverter, the output end of the first inverter is connected with the input end of the second inverter, the output end of the second inverter is connected with the input end of the third inverter, one end of the first capacitor is connected with the output end of the first inverter, and the other end of the first capacitor is grounded; and the output end of the first inverter is used for receiving the voltage control signal, and the output end of the third inverter is used for outputting the first tuning signal to the boost circuit.

In the embodiment of the present application, the first tuning circuit may control the high signal value of the square wave ac electric field in an analog manner (for example, a manner shown in fig. 8 below) or in a manner of combining analog with digital (for example, a manner shown in fig. 9A and 9B below) or in a digital manner (for example, an embodiment shown in fig. 10 below), so as to adjust the light emitting brightness of the electroluminescent device, and increase the manner of adjusting the light emitting brightness of the electroluminescent device.

In a possible implementation manner of the first aspect, an output terminal of the first inverter is further connected to one end of a first resistor, and the other end of the first resistor is configured to receive a voltage control signal.

That is, in the embodiment of the present application, the first tuning circuit may receive the voltage control signal, for example, the voltage control signal of the dc voltage, the voltage control signal of the square wave, etc., through the first resistor, so as to control the high signal value of the square wave ac electric field through an analog manner (for example, a manner shown in fig. 8 below) or a manner of combining the analog and the digital manners (for example, a manner shown in fig. 9A and 9B below), thereby adjusting the light emitting brightness of the electroluminescent device, and increasing the manner of adjusting the light emitting brightness of the electroluminescent device.

In one possible implementation of the first aspect, the boost circuit includes: a MOSFET, an inductor, a diode, and a second capacitor; the grid electrode of the MOSFET is used for receiving a first tuning signal, the source electrode of the MOSFET is grounded and connected with one end of the second capacitor, the drain electrode of the MOSFET is connected with one end of the inductor and the anode of the diode, the other end of the inductor is used for receiving a first voltage, and the cathode of the diode is connected with the other end of the second capacitor; the cathode of the diode is used for outputting a second voltage to the full-bridge driving circuit.

In a possible implementation of the first aspect, the second tuning circuit includes: a fourth inverter, a fifth inverter, a sixth inverter, and a third capacitor; the input end of the fourth inverter is connected with the output end of the sixth inverter, the output end of the fourth inverter is connected with the input end of the fifth inverter, the output end of the fifth inverter is connected with the input end of the sixth inverter, one end of the third capacitor is connected with the output end of the fourth inverter, and the other end of the third capacitor is grounded; and the output end of the fourth inverter is used for receiving the waveform control signal, and the output end of the sixth inverter is used for outputting a second tuning signal to the full-bridge driving circuit.

In the embodiment of the present application, the second tuning circuit may control the frequency of the square wave ac electric field in an analog manner (for example, the manner shown in fig. 12 below) or in a combination of analog and digital manners (for example, the manner shown in fig. 13A and 13B below) or in a digital manner (for example, the embodiment shown in fig. 14 below), so as to adjust the light emission color of the electroluminescent device, and increase the manner of adjusting the light emission color of the electroluminescent device.

In a possible implementation of the first aspect, an output terminal of the fourth inverter is further connected to one end of a second resistor, and the other end of the second resistor is configured to receive a waveform control signal.

In the embodiment of the present application, the second tuning circuit may adjust the light emitting color of the electroluminescent device by an analog manner (for example, a manner shown in fig. 12 below) or a manner of combining analog and digital manners (for example, a manner shown in fig. 13A and 13B below), which increases the manner of adjusting the light emitting color of the electroluminescent device.

In one possible implementation of the first aspect, the full-bridge driving circuit includes: full bridge output drive, first P-channel MOSFET, second P-channel MOSFET, first N-channel MOSFET, and second N-channel MOSFET; the full-bridge output driver comprises a control signal input end, a voltage input end, a first output end, a second output end, a third output end and a fourth output end, wherein the control signal input end is used for receiving a second tuning signal, and the voltage input end is used for receiving a second voltage; the first output end is connected with the grid electrode of the first P-channel MOSFET, the second output end is connected with the grid electrode of the first N-channel MOSFET, the third output end is connected with the grid electrode of the second P-channel MOSFET, the fourth output end is connected with the grid electrode of the first N-channel MOSFET, the source electrode of the first P-channel MOSFET and the source electrode of the second P-channel MOSFET are used for receiving a second voltage, the source electrode of the first N-channel MOSFET and the drain electrode of the second N-channel MOSFET are grounded, the drain electrode of the first P-channel MOSFET is connected with the source electrode of the first N-channel MOSFET, the drain electrode of the second P-channel MOSFET is connected with the source electrode of the second N-channel MOSFET, and the drain electrode of the first P-channel MOSFET and the drain electrode of the second P-channel MOSFET are used for outputting square wave alternating current signals to the electroluminescent device;

The full-bridge output drive outputs a voltage for turning on the first P-channel MOSFET to the first output terminal, a voltage for turning off the first N-channel MOSFET to the second output terminal, a voltage for turning off the second P-channel MOSFET to the third output terminal, and a voltage for turning on the second N-channel MOSFET to the fourth output terminal when the second tuning signal is a high electrical signal, and outputs a voltage for turning off the first P-channel MOSFET to the first output terminal, a voltage for turning on the first N-channel MOSFET to the second output terminal, a voltage for turning on the second P-channel MOSFET to the third output terminal, and a voltage for turning off the second N-channel MOSFET to the fourth output terminal when the second tuning signal is a low electrical signal; or the full bridge output drive outputs a voltage for turning on the first P-channel MOSFET to the first output terminal, a voltage for turning off the first N-channel MOSFET to the second output terminal, a voltage for turning off the second P-channel MOSFET to the third output terminal, and a voltage for turning on the second N-channel MOSFET to the fourth output terminal when the second tuning signal is a low electric signal, and outputs a voltage for turning off the first P-channel MOSFET to the first output terminal, a voltage for turning on the first N-channel MOSFET to the second output terminal, a voltage for turning on the second P-channel MOSFET to the third output terminal, and a voltage for turning off the second N-channel MOSFET to the fourth output terminal when the second tuning signal is a high electric signal.

Drawings

FIG. 1 illustrates an application scenario diagram of an EL device, according to some embodiments of the present application;

FIG. 2 illustrates a schematic diagram of an EL device driving circuit, according to some embodiments of the present application;

FIG. 3A illustrates a schematic diagram of an EL device driving circuit based on a full bridge driving circuit, according to some embodiments of the present application;

FIG. 3B is a schematic diagram showing the output signal of PWM switching oscillator 3-1 and the voltage applied by full-bridge drive circuit 3-2 to EL device 3-EL, according to some embodiments of the present application;

FIG. 4 illustrates a schematic diagram of a drive circuit suitable for use in a high voltage EL device, according to some embodiments of the present application;

FIG. 5 illustrates a sinusoidal AC electrical signal U, according to some embodiments of the application ₁ Sum square wave ac signal U ₂ Schematic of (2);

fig. 6 shows a schematic diagram of a driving circuit 11 according to some embodiments of the application;

FIG. 7 shows a schematic circuit diagram of one specific implementation of the drive circuit 11, according to some embodiments of the application;

fig. 8 illustrates a schematic circuit connection diagram of a first tuning signal that controls the output of the first tuning circuit 110 in an analog manner, according to some embodiments of the application;

Fig. 9A illustrates a schematic circuit connection diagram of a first tuning signal that controls the output of the first tuning circuit 110 by a combination of analog and digital signals, according to some embodiments of the application;

FIG. 9B illustrates a comparative schematic diagram of a voltage control signal, an intrinsic signal of a first tuning circuit, and a first tuning signal, according to some embodiments of the application;

fig. 10 illustrates a circuit connection diagram of a first tuning signal that is controlled by a digital signal to be output by the first tuning circuit 110, according to some embodiments of the present application;

FIG. 11 shows a frequency and pulse width of a first tuning signal, a quality factor and limiting current of an inductor L, a voltage V output by a boost circuit 111, according to some embodiments of the application _C A schematic diagram of a constraint relation between the output power of the booster circuit 111;

fig. 12 illustrates a schematic circuit connection diagram of a second tuning signal that controls the output of the second tuning circuit 112 in an analog manner, according to some embodiments of the application;

fig. 13A illustrates a schematic circuit diagram of a circuit connection for controlling a second tuning signal output by a second tuning circuit 112 by a combination of analog and digital signals, in accordance with some embodiments of the present application;

FIG. 13B illustrates a schematic diagram of a waveform control signal, an intrinsic signal of a second tuning circuit, and a comparison of a second tuning signal, in accordance with some embodiments of the application;

fig. 14 illustrates a schematic circuit connection diagram of a second tuning signal that is controlled by a digital signal to be output by the second tuning circuit 112, according to some embodiments of the present application;

fig. 15 shows a schematic diagram of a packaged driver circuit 11, according to some embodiments of the application;

fig. 16A illustrates a schematic diagram of a drive circuit that does not include the first tuning circuit 110, according to some embodiments of the application;

FIG. 16B illustrates a schematic diagram of a drive circuit that does not include the second tuning circuit 112, according to some embodiments of the application;

fig. 16C illustrates a schematic diagram of a drive circuit that does not include the first tuning circuit 110 and the second tuning circuit 112, in accordance with some embodiments of the application;

fig. 17 illustrates a schematic diagram of a tuning circuit 120, according to some embodiments of the application;

FIG. 18 is a schematic diagram showing the structure of an EL driving device according to some embodiments of the present application;

fig. 19 is a flow chart illustrating a method of driving an EL device according to some embodiments of the application.

Detailed Description

Illustrative embodiments of the application include, but are not limited to, electronic devices.

First, terms related to the embodiments of the present application will be described.

(1) EL device

An EL device is a device that emits light by the principle of electroluminescence, that is, an electric field is generated by a voltage across electrodes of the EL device, and electrons excited by the electric field collide with a luminescence center, causing transition, change, and recombination of electrons between energy levels, resulting in light emission. The light emission luminance of the EL device is correlated with the peak value of the alternating current signal applied to the EL device, for example, the light emission luminance increases with an increase in the peak value of the alternating current signal. For an EL device that can emit multiple colors, the color of the light emitted by the EL device can be adjusted by adjusting the frequency of the alternating electrical signal applied to the EL device.

The technical scheme of the embodiment of the application is described below with reference to the accompanying drawings.

Fig. 1 illustrates an application scenario diagram of an EL device, according to some embodiments of the application.

As shown in fig. 1, the smart band 1 includes a processor 10, a driving circuit 11, and an EL device 12. Wherein the processor 10 is coupled to the driving circuit 11 for sending control signals to the driver 11; the driving circuit 11 may apply ac electric signals of different frequencies, voltages, waveforms to the EL device 12 according to the control signal applied by the processor 10, so that the EL device 12 may emit light of different brightness, colors; the EL device 12 may include a display unit, an indicator light, or the like in the smart band 1. In order to ensure that the EL device 12 emits light of different brightness and color, the peak value and frequency of the ac signal that the driving circuit 11 needs to output can be adjusted by applying different control signals to the driving circuit. The driving circuit 11 is required to have low power consumption, high efficiency, and small size due to the small size and small battery capacity of the smart band 1.

Currently, the driving circuit of an EL device generally drives the EL device by a sine wave alternating current signal.

For example, fig. 2 shows a schematic diagram of an EL device driving circuit. Referring to fig. 2, the circuit converts a low voltage dc power supply 1-VDD (voltage 2-6V) into a low voltage ac signal (applied to an inductor L-1) based on an EL driving chip WD26F and its accessory circuits, and the inductor L-1 forms a coil N1, and the inductor L-2 and the inductor L-3 connected in series form a coil N2, so that the coil N1 and the coil N2 are coupled based on a transformer principle, and the ac signal with a lower voltage can be converted into an ac signal with a higher voltage that meets the requirements of the EL device 2-EL, and then applied to the EL device 2-EL. Since the conversion of the low-voltage ac signal into the high-voltage ac signal is achieved by the coupling of the coil N1 and the coil N2 based on the transformer principle, the ac signal applied to the 2-EL is a sine wave ac signal.

For another example, fig. 3A shows a schematic diagram of an EL device driving circuit based on a full-bridge driving circuit. As shown in fig. 3A, the driving circuit adjusts the peak value of the voltage applied to the full-bridge driving circuit 3-2 by generating a PWM wave with a duty ratio of 0-88% by a pulse width modulation (Pulse Width Modulation, PWM) switching oscillator 3-1 (wherein the duty ratio of the PWM switching oscillator 3-1 is controlled by a resistor R) _SWOSC Determined) and through resistance R _EL To adjust the frequency of the sine wave ac electrical signal input to the full-bridge drive circuit 3-2, i.e., the frequency of the ac electrical signal applied to the EL device 3-EL by the full-bridge drive circuit 3-2. For example, FIG. 3B shows a schematic diagram of the output signal of the PWM switching oscillator 3-1 and the voltage applied to the EL device 3-EL by the full-bridge drive circuit 3-2. As can be seen from fig. 3B, the ac signal applied to the EL device 3-EL by the driving circuit is a sine wave ac signal. In addition, the peak value of the sine wave alternating current signal is represented by a resistor R _SWOSC The frequency is determined by a resistor R _EL It was determined that the adjustment of the emission luminance and emission color of the EL device could not be achieved without being adjusted by applying different control signals to the circuit.

For another example, fig. 4 shows a schematic diagram of a driving circuit suitable for a high-voltage EL device, in which driving circuit 4-10, a low-voltage input voltage 4-13 is converted into a high-voltage direct-current voltage by a charge pump circuit 4-12, and the high-voltage direct-current voltage is mainly used as an input voltage of a switching circuit 4-14; the oscillator 4-18 provides a periodic control signal to the switching circuit 4-14, when the control signal is valid, the switching circuit 4-14 outputs the high voltage direct current voltage to the high voltage EL device 4-EL, when the control signal of the oscillator is invalid, the switching circuit 4-14 outputs 0V voltage to the high voltage EL device 4-EL, so that the frequency of the control signal generated by the oscillator 4-18 is the frequency of the voltage applied to the high voltage EL device 4-EL by the driving circuit, and the high voltage direct current voltage generated by the charge pump circuit 4-12 is the peak value of the voltage applied to the high voltage EL device 4-EL by the driving circuit. In this drive circuit, since the peak value and frequency of the voltage applied to the high-voltage EL device 4-EL cannot be adjusted by applying different control signals to the circuit, adjustment of the light emission luminance and light emission color of the EL device cannot be achieved, and the EL device for the wearable apparatus does not require a too high drive voltage.

Each of the driving circuits drives the EL device by applying a sine wave ac signal to the EL device, which results in a large energy waste and affects the cruising ability of the electronic device using the EL device and each of the driving circuits.

For example, referring to FIG. 5, an EL device is formed from a sine wave AC signal U of period T and peak voltage A shown in FIG. 5 ₁ The EL device is driven with a voltage threshold of 0.78A at a certain luminance. Sine wave ac electric signal at t ₁ Time increases from small to large to 0.78A at t ₂ Time decreases from big to small to 0.78A, and t ₂ -t ₁ Needs to be greater than a preset drive time threshold (e.g., t ₂ -t ₁ Greater than one tenth of the period of the sinusoidal ac electrical signal U1). Let the representation of a sine wave ac electrical signal be U ₁ The impedance of the EL device is Z, and the sine wave ac signal U can be obtained ₁ To drive the EL device, at t ₁ From time to t ₂ Energy consumption E during time of day ₁ Can be used forExpressed as the following formula (1).

In the formula (1), omega is a sine wave alternating current electric signal U ₁ A kind of electronic device angular frequency.

It is understood that the conditions under which the EL device normally emits light at a certain luminance include: the peak value of the alternating current signal is greater than or equal to the voltage threshold of the brightness, and the duration of the alternating current signal being greater than the voltage threshold of the brightness is greater than a preset time threshold (e.g., 1/10 of a period of the large alternating current signal). That is, t is as described above ₁ From time to t ₂ During the time, the voltage of the ac electric signal is not less than 0.78A, and the EL device can be driven to normally emit light at the luminance. For example, it may be shown in FIG. 5 that within a single period T, T ₁ From time to t ₂ Square wave ac electric signal U with voltage value of 0.78A during time and voltage value of 0 at other time ₂ To achieve the sine wave AC electric signal U ₁ Is provided.

And pass through the square wave ac electric signal U shown in fig. 5 ₂ Driving the EL device at t ₁ From time to t ₂ Energy consumption E during time of day ₂ Can be expressed as the following formula (2).

Due tot ₂ ＝0.5T-t ₁ ，/>Let->Then (E) can be obtained according to the formula (1) and the formula (2) ₁ -E ₂ )/E ₁ About 0.41. That is, in the alternating current signal U ₁ In the case of a frequency of 1/t=1200 Hz, a square-wave ac electrical signal U is used ₂ To drive the EL device by a sine wave AC electric signal U ₁ Saving 41% of energy consumption.

Based on the theory, the embodiment of the application provides a driving circuit, which can drive an EL device through square-wave alternating current signals, can reduce the electric energy consumed by the EL device and improve the endurance of electronic equipment. Specifically, referring to fig. 6, the driving circuit 11 includes a first tuning circuit 110, a booster circuit 111, a second tuning circuit 112, and a full-bridge driving circuit 113, and input terminals of the driving circuit 11 include a voltage control signal input terminal S1, a direct-current voltage input terminal VDD, a waveform control signal input terminal S2, a ground terminal GND, and output terminals include an output terminal OUT1 and an output terminal OUT2.

The first tuning circuit 110 is configured to receive an external voltage control signal, for example, a voltage control signal sent by the processor 10, through the voltage control signal input terminal S1, and output a first tuning signal, for example, a square wave signal with a different duty cycle, according to the voltage control signal.

The booster circuit 111 boosts the dc input voltage of the lower voltage input from the dc voltage input terminal VDD to the dc voltage V of the higher voltage according to the first tuning signal output from the first tuning circuit 110 _C Output, DC voltage V _C The magnitude of (a) increases with increasing duty cycle of the first tuning signal.

The second tuning circuit 112 is configured to receive an external waveform control signal, such as an output control signal transmitted by the aforementioned processor 10, through the waveform control signal input terminal S2, and output a second tuning signal of a different frequency and duty cycle according to the waveform control signal, and the waveform of the second tuning signal is a square wave.

It will be appreciated that in some embodiments, the second tuning circuit 112 may not receive the waveform control signal from the outside to generate the second tuning signal, but rather may be self-generating a second tuning signal of a fixed frequency and pulse width, e.g., the second tuning circuit 112 may be implemented as a relaxation oscillator outputting a square wave.

The input of the full-bridge drive circuit 113 includes a second tuning signal and a DC voltage V output by the boost circuit 111 _C And outputs the driving voltage V through the output terminal OUT1 and the output terminal OUT2 in a case where the second tuning signal is active (for example, during a high level of a square wave) _C In the case where the second tuning signal is inactive (for example, during a low level of a square wave), the driving voltage V is outputted through the output terminal OUT1 and the output terminal OUT2 _C Is the inverse voltage of-V _C So that the driving electric signals U output from the output terminals OUT1 and OUT2 _D For the same frequency and waveform as the second tuning signal, the high level is V _C At low level of-V _C Is a square wave ac signal.

It will be appreciated that in other embodiments, the full-bridge drive circuit 113 may also output the drive voltage V through the output terminal OUT1 and the output terminal OUT2 during the low level of the square wave corresponding to the second tuning signal _C During the high level of the square wave corresponding to the second tuning signal, the driving voltage V is output through the output terminal OUT1 and the output terminal OUT2 _C Is the inverse voltage of-V _C 。

That is, the driving circuit 11 outputs the square-wave ac electric signal U through the output terminal OUT1 and the output terminal OUT2 _D The frequency of (a) may be adjusted by the waveform control signal, and the peak value (high level) may be adjusted by the voltage control signal, thereby adjusting the brightness and color of the EL device connected between the output terminal OUT1 and the output terminal OUT 2.

It will be appreciated that the square wave ac electrical signal may be an ac voltage signal or an ac current signal, which is not limited herein, and is described in the following embodiments by way of example.

Compared with a driving circuit which adopts sine wave alternating current signals to drive the EL device, the driving circuit 11 provided by the embodiment of the application can reduce energy consumption, thereby reducing the electric energy consumption of electronic equipment (such as the intelligent bracelet 1) adopting the driving circuit 11 and further improving the cruising ability of the electronic equipment. Also, the driving circuit 11 can adjust the voltage and frequency of the square wave ac electric signal applied to the EL device by receiving an external voltage control signal and an output control signal, thereby adjusting the light emission luminance and light emission color of the EL device.

For example, the smart band 1 can adjust the frequency of the first tuning signal by inputting different voltage control signals to the voltage control signal input terminal S1, thereby adjusting the square wave ac electric signal U applied to the EL device 12 by the driving circuit 11 _D Thereby adjusting the light emission luminance of the EL device 12; the smart band 1 can also adjust the frequency of the second tuning signal by inputting a different output control signal to the waveform control signal input terminal S2, thereby adjusting the U of the square wave ac electric signal applied to the EL device 12 by the driving circuit 11 _D And thus adjusts the color of EL device 12. Specifically, the smart bracelet 1 may gradually darken the brightness of the EL device 12 from light to dark and then gradually lighten from dark by inputting a voltage control signal with a duty ratio gradually from large to small and then gradually from small to large to the voltage control signal input terminal S1, thereby forming a breathing lamp effect; the smart band 1 can also gradually change the color of the EL device 12 by inputting a waveform control signal whose frequency gradually changes from high to low and then gradually changes from low to high to the waveform control signal input terminal S2.

Further, fig. 7 shows a circuit schematic of a specific implementation of the driving circuit 11, according to an embodiment of the application.

As shown in fig. 7, the first tuning circuit 110 includes a first inverter PI1, a second inverter PI2, a third inverter PI3, and a capacitor C1 (first capacitor). The input end of the first inverter PI1 is connected with the output end of the third inverter PI3, the output end of the first inverter PI1 is connected with the input end of the second inverter PI2, the output end of the second inverter PI2 is connected with the input end of the third inverter, one end of the capacitor C1 is connected with the output end of the first inverter PI1 (the input end of the second inverter PI 2) and the other end of the capacitor C1 is grounded. The input terminal of the first tuning circuit 110 is an output terminal of the first inverter PI1 (an input terminal of the second inverter PI 2), which is connected to the voltage control signal input terminal S1 of the driving circuit 11 for receiving the voltage control signal, and the output terminal of the first tuning circuit 110 (a first tuning signal output terminal) is an output terminal of the third inverter PI3 (an input terminal of the first inverter PI 1) for outputting the first tuning signal to the booster circuit 111.

It will be appreciated that in some embodiments, the first, second, and third inverters PI1, PI2, PI3 may have the same bias voltage (also referred to as a gate-on voltage in some embodiments) V _bias1 When the voltage input to each inverter is greater than the bias voltage, the inverter output is set to 1 (output high level), and when the voltage input to each inverter is less than the bias voltage, the output of each inverter is set to 0 (i.e., output low level).

In other embodiments, the first tuning signal output by the first tuning circuit 110 may also be controlled in an analog manner, i.e. the adjustment of the first tuning signal is achieved by parameters of different analog devices. For example, fig. 8 illustrates a schematic circuit connection diagram of a first tuning signal that controls the output of the first tuning circuit 110 in an analog manner, according to some embodiments of the application.

Referring to fig. 8, the voltage control signal input terminal S1 may be connected to one end of a resistor R1 (first resistor) and a direct voltage signal VDD is input to the other end of the resistor R1, thereby implementing adjustment of the second tuning signal using an analog signal. The voltage signal VDD charges the capacitor C1 through the resistor R1, and the voltage charged to the two ends of the capacitor C1 is larger than V _bias1 When the voltage at the input end of the second inverter PI2 is greater than V _bias1 The second inverter PI2 outputs a low level, so that the output of the third inverter PI3 is a high level, so that the output of the first inverter PI1 is a low level, and the capacitor C1 is discharged through the first inverter PI 1. The voltage across capacitor C1 to discharge C1 is less than V _bias1 When the voltage at the input end of the second inverter PI2 is smaller than V _bias1 The second inverter PI2 outputs a high level, so that the output of the third inverter PI3 is a low level. In this way, the level of the output of the third inverter PI3 is periodically switched between a high level and a low level to form a frequency f ₁ I.e. the first tuning signal).

It will be appreciated that in some embodiments, the frequency f of the first tuning signal ₁ Can be calculated by the following formula (3).

F in formula (3) ₁ For the frequency of the first tuning signal, R ₁ Is the resistance value of the resistor R1, C ₁ Is the capacitance of the capacitor C1. In other embodiments, the frequency f of the first tuning signal ₁ The calculation may also be performed in other forms, and is not limited herein. In some embodiments, f is as described above ₁ May also be referred to as the natural frequency of the first tuned circuit. That is, the frequency of the first tuning signal can be adjusted by using different resistors R1 and capacitors C1.

It will be appreciated that the bias voltage V of the second inverter can be used _bias1 To adjust the pulse width W of the first tuning signal ₁ At VDD, R ₁ 、C ₁ In a certain case, the higher the bias voltage of the second inverter PI2, the longer the time to charge the capacitor C1, the pulse width W of the first tuning signal ₁ The wider, that is, the bias voltage V of each inverter can be adjusted _bias1 To adjust the pulse width W of the first tuning signal ₁ 。

In some embodiments, the first tuning signal output by the first tuning circuit 110 may also be controlled by a combination of analog and digital signals, i.e. the adjustment of the first tuning signal is achieved by parameters of different analog devices and by inputting different digital signals to the first tuning circuit 110. For example, fig. 9A illustrates a schematic circuit connection diagram of a first tuning signal that controls the output of the first tuning circuit 110 by a combination of analog and digital signals, according to some embodiments of the application.

Referring to fig. 9A, the voltage control signal input terminal S1 may be connected to one end of the resistor R1, and input a frequency f at the other end of the resistor R1 ₁ Square wave so that the duty of the signal can be controlled by the voltageThe duty ratio (or pulse width) of the first tuning signal is adjusted to adjust the duty ratio (pulse width) of the first tuning signal, and the driving voltage V output by the booster circuit 111 is further adjusted _C . For example, the resistor R1 is configured to receive the voltage control signal at a frequency f ₁ Pulse width W _S1 Of (wherein W _S1 ≤W ₁ ) During the period when the voltage control signal is low, the input end of the second inverter PI2 is low, the output end is high, the output end of the third inverter PI3 is low, during the period when the voltage control signal is high, the input end of the second inverter PI2 is high, the output end is low, the output end of the third inverter PI3 is high, that is, the first tuning signal is high when the voltage control signal is high, the pulse width W of the voltage control signal is adjusted _S1 I.e. the pulse width of the first tuning signal can be adjusted (since pulse width = duty cycle x period, the pulse width is adjusted, i.e. the duty cycle is adjusted). For example, referring to fig. 9B, the natural frequency of the first tuning circuit 110 is f ₁ Pulse width W ₁ The frequency of the voltage control signal is f ₁ Pulse width W _S1 ＝0.5W ₁ The first tuning signal is at a high level only when the voltage control signal and the inherent signal of the first tuning circuit are both at a high level, so that the first tuning signal is at a frequency f ₁ Pulse width of 0.5W ₁ Is a square wave of (c).

In other embodiments, the first tuning signal output by the first tuning circuit 110 may also be controlled by a digital signal only, i.e. by inputting a different digital signal to the first tuning circuit 110. For example, fig. 10 illustrates a schematic circuit connection diagram of a first tuning signal that is controlled by a digital signal to be output by the first tuning circuit 110, according to some embodiments of the application.

Referring to fig. 10, the voltage control signal may be directly input to the voltage control signal input terminal S1. Since there is no resistor and capacitor C1 connection, the first inverter PI1 is bypassed (i.e., the first inverter does not affect the output of the first tuning circuit 110), and the voltage at the input of the second inverter PI2 is consistent with the voltage control signalThe output is opposite to the voltage control signal so that the output voltage of the third inverter PI3 (i.e., the output voltage of the first tuning circuit 110) is the same as the voltage control signal. That is, the waveform of the first tuning signal is the same as the voltage control signal input terminal S1 inputs the voltage control signal. For example, assume that the voltage control signal input to the voltage control signal input terminal S1 has a frequency f _S1’ Pulse width W _S1’ The first tuning signal output by the first tuning circuit 110 is also a square wave with a frequency f _S1’ Pulse width W _S1’ Is a square wave of (c). And then the first tuning signal can be adjusted by adjusting the frequency and the pulse width of the voltage control signal.

That is, the first tuning circuit 110 provided in the embodiment of the present application may generate the first tuning signal with a fixed pulse width and frequency under the condition of not receiving the external control signal (input dc voltage, refer to the embodiment of fig. 8), and drive the EL device to emit light with a fixed brightness, or may receive the external digital signal/analog signal to adjust the first tuning signal, thereby adjusting the peak value of the ac electrical signal applied to the EL device by the driving circuit 11, and further adjusting the light emitting brightness of the EL device, and increasing the versatility of the driving circuit 11.

With continued reference to fig. 7, the boost circuit 111 includes a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) M1, an inductance L, a diode D, and a capacitor C2 (second capacitor). The gate of the MOSFET M1 is connected to the output end of the third inverter PI3 (i.e., the output end of the first tuning circuit 110), the source of the MOSFET M1 is grounded, the drain of the MOSFET M1 is connected to one end of the inductor L and the anode of the diode D, and the other end of the inductor L is connected to the dc voltage input terminal VDD; the cathode of the diode D is grounded to one end of the capacitor C2, and the other end of the capacitor C2 is grounded. The input end of the boost circuit 111 is the gate of the MOSFET M1, the output end is the cathode of the diode D, and the output end is connected with the voltage terminal V113 of the full-bridge output driver 1131, the source of the P-channel MOSFET M2 and the source of the P-channel MOSFET M4 in the full-bridge driving circuit 113 to provide the driving voltage V to the full-bridge driving circuit 113 _C 。

At the first stageWhen the tuning signal is at a low level, the MOSFET M1 is turned off, the inductor L charges the capacitor C2, and the voltage at two ends of the capacitor C2 can be higher than the voltage of the direct-current voltage input terminal VDD due to the large capacity of the capacitor C2; when the first tuning signal is at a high level, the MOSFET M1 is turned on, the direct-current voltage inductor L no longer charges the capacitor C2, and the voltage across the capacitor C2 does not drop sharply but drops slowly during the power supply of the full-bridge driving circuit 113 due to the larger capacity of the capacitor C2, and the larger the duty ratio of the first tuning signal, the higher the frequency, and the smaller the voltage variation across the capacitor C2, i.e., V under a certain load condition _C The greater the effective value of (2). That is, the duty ratio of the first tuning signal output from the first tuning circuit 110 is adjusted by the voltage control signal, that is, the driving voltage V output from the booster circuit 111 to the full-bridge driving circuit 113 is adjusted _C Further, the peak value of the ac electric signal applied to the EL device through the output terminal OUT1 and the output terminal OUT2 is adjusted to realize adjustment of the luminance of the EL device.

It will be appreciated that, with the booster circuit 111 shown in fig. 7, in the case where the impedance of the EL device to be driven is constant, if the luminance of the EL device is to be increased, the voltage V outputted from the booster circuit 111 needs to be increased _C I.e. to increase the power of the boost circuit 111. As described above, the waveform of the first tuning signal can be adjusted to increase the voltage V output from the booster circuit 111 _C For example, increasing the frequency and pulse width of the first tuning waveform. However, when the frequency is increased, that is, the number of times of charging the capacitor C2 per unit time is increased, the voltage is increased, but due to the limitation of the quality factor of the inductor L, the energy consumed by the inductor L is also increased, so that the boosting efficiency and the output effect are reduced; when the pulse width is increased, i.e. the electric energy stored in the inductor L is increased in a single period, the voltage is increased, but the pulse width cannot be increased without limit due to the limit of the limiting current of the inductor to avoid damaging the inductor L, and the boosting efficiency and the output effect are also reduced due to the limit of the quality factor of the inductor L. It can be seen from this that, referring to fig. 11, the frequency and pulse width of the first tuning signal, the quality factor and limiting current of the inductance L, the voltage V output from the booster circuit 111 _C And boosting upThe output power of the circuits 111 are mutually restricted, and the quality factor and the limiting current of the inductance L are determined values for one determined booster circuit 111, so that the boosting efficiency of the booster circuit can be improved by adjusting the frequency and the pulse width to the first tuning waveform.

For example, in some embodiments, after the boost circuit 111 is determined, the boost circuit 111 may be driven to output the voltage V by first tuning signals of different frequencies and/or different pulse width combinations _C A pulse width that maximizes the boosting efficiency of the booster circuit 111 at different frequencies and/or a frequency that maximizes the boosting efficiency of the booster circuit 111 at different pulse widths are obtained. The frequency of the first tuning signal generated by the first tuning circuit 110 can be obtained by the above formula (3), and the pulse width of the first tuning signal can be adjusted to the pulse width that makes the boosting circuit 111 boost the best efficiency at the above frequency by adjusting the bias voltage of the second inverter PI2 or changing the pulse width of the voltage control signal. In this way, the boosting efficiency of the booster circuit 111 can be improved.

With continued reference to fig. 7, the second tuning circuit 112 includes a fourth inverter PI4, a fifth inverter PI5, a sixth inverter PI6, and a capacitor C3 (third capacitor). The input end of the fourth inverter PI4 is connected to the output end of the sixth inverter PI6, the output end of the fourth inverter PI4 is connected to the input end of the fifth inverter PI5, the output end of the fifth inverter PI5 is connected to the input end of the sixth inverter, one end of the capacitor C3 is connected to the output end of the fourth inverter PI1 (the input end of the fifth inverter PI 5), and the other end is grounded. The input end of the second tuning circuit 112 is the output end of the fourth inverter PI4 (the input end of the fifth inverter PI 2), which is connected to the waveform control signal input terminal S2 of the driving circuit 11 for receiving the waveform control signal, and the output end of the second tuning circuit 112 is the output end of the sixth inverter PI6 (the input end of the fourth inverter PI 4) for outputting the second tuning signal to the full-bridge driving circuit 113.

It will be appreciated that in some embodiments, the fourth, fifth, and sixth inverters PI4, PI5, PI6 may have the same bias voltage (also referred to as a gate-on voltage in some embodiments) V _bias2 In the followingWhen the voltage input to each inverter is greater than the bias voltage, the inverter output is set to 1 (output high level), and when the voltage input to each inverter is less than the bias voltage, the output of each inverter is set to 0 (i.e., output low level).

In some embodiments, the second tuning signal output by the second tuning circuit 112 may also be controlled in an analog manner, i.e. the adjustment of the second tuning signal is achieved by parameters of different analog devices. For example, fig. 12 illustrates a schematic circuit connection diagram of a second tuning signal that controls the output of the second tuning circuit 112 in an analog manner, according to some embodiments of the application.

Referring to fig. 12, the waveform control signal input terminal S2 may be connected to one end of a resistor R2 (second resistor), and a voltage signal VDD of direct current is input to the other end of the resistor R2, thereby realizing adjustment of the second tuning signal using an analog signal. The voltage signal VDD charges the capacitor C3 through the resistor R2, and the voltage charged to the two ends of the capacitor C3 is greater than V _bias2 The voltage at the input terminal of the fifth inverter P52 is greater than V _bias2 The fifth inverter PI5 outputs a low level, so that the output of the sixth inverter PI6 is a high level, so that the output of the fourth inverter PI4 is a low level, and the capacitor C3 is discharged through the fourth inverter PI 4. The voltage across capacitor C3 to discharge C3 is less than V _bias3 When the voltage at the input end of the fifth inverter PI5 is smaller than V _bias2 The fifth inverter PI5 outputs a high level, so that the output of the sixth inverter PI6 is a low level. In this way, the level of the output of the sixth inverter PI6 is periodically switched between the high level and the low level to form a frequency f ₂ I.e. the first tuning signal).

It will be appreciated that in some embodiments, the frequency f of the second tuning signal ₂ Can be calculated by the following formula (4).

F in formula (4) ₂ For the frequency of the second tuning signal, R ₂ Is the resistance value of the resistor R2，C ₃ Is the capacitance of capacitor C3. In other embodiments, the frequency f of the second tuning signal ₂ The calculation may also be performed in other forms, and is not limited herein. In some embodiments, f is as described above ₂ May also be referred to as the natural frequency of the second tuning circuit.

It will be appreciated that the bias voltage V of the fifth inverter can be used _bias2 To adjust the pulse width W of the second tuning signal ₂ At VDD, R ₂ 、C ₃ In a certain case, the higher the bias voltage of the fifth inverter PI5, the longer the time to charge the capacitor C3, the pulse width W of the second tuning signal ₂ The wider, that is, the bias voltage V of each inverter can be adjusted _bias1 To adjust the pulse width W of the second tuning signal ₂ . In the case of a constant capacitance C3 and by adjusting the size of the resistor R2, the frequency f of the second tuning signal can be adjusted ₂ The larger the resistance R2, the frequency f of the second tuning signal ₂ The lower.

In some embodiments, the second tuning signal output by the second tuning circuit 112 may also be controlled by a combination of analog and digital signals, i.e., the adjustment of the second tuning signal is achieved by different parameters of the analog device and different digital signals input to the second tuning circuit 112. For example, fig. 13A illustrates a schematic diagram of a circuit connection for controlling a second tuning signal output by the second tuning circuit 112 by a combination of analog and digital signals, according to some embodiments of the application.

Referring to fig. 13A, the waveform control signal input terminal S2 may be connected to one end of the resistor R2, and input a frequency f at the other end of the resistor R2 ₂ N, pulse width of n.W ₂ (n is a positive integer), that is, by using different n to input square waves with different frequencies to the second tuning circuit 112, the frequency and duty ratio of the second tuning signal are adjusted, and thus the frequency of the ac driving voltage output by the full-bridge driving circuit 113 is adjusted. For example, the resistor R2 is used to receive the waveform control signal at the end of the waveform control signal with the frequency f ₂ N, pulse width of n.W ₂ (n is a positive integer)A square wave in which the input terminal of the fifth inverter PI5 is low and the output terminal is high during the low level period of the waveform control signal, so that the output terminal of the sixth inverter PI6 is low, and the input terminal of the fifth inverter PI5 is high and the output terminal is low when the voltage control signal is high and the inherent signal of the second tuning circuit 112 is high, so that the output terminal of the sixth inverter PI6 is high, that is, the frequency of the second tuning signal is the same as that of the waveform control signal (i.e., f ₂ /n). For example, referring to fig. 13B, the natural frequency of the second tuning circuit 112 is f ₂ Pulse width W ₂ The frequency of the waveform control signal is f ₁ 2, pulse width of 2W ₂ The second tuning signal is at a high level only when the waveform control signal and the inherent signal of the second tuning circuit are both at a high level, so that the second tuning signal is at a frequency f ₂ 2, pulse width of 2W ₂ Is a square wave of (c).

In other embodiments, the adjustment of the second tuning signal may also be achieved by controlling the first tuning signal output by the second tuning circuit 112 only by a digital signal, i.e. by inputting a different digital signal to the second tuning circuit 112. For example, fig. 14 illustrates a schematic circuit connection diagram of a second tuning signal that is controlled by a digital signal to be output by the second tuning circuit 112, according to some embodiments of the application.

Referring to fig. 14, the waveform control signal may be directly input to the waveform control signal input terminal S2. Since there is no resistor and capacitor C3 connection, the fourth inverter PI4 is bypassed (i.e., the fourth inverter PI4 does not affect the output of the second tuning circuit 112), the voltage at the input of the fifth inverter PI5 is identical to the waveform control signal and the output is opposite to the waveform control signal, so that the output voltage of the sixth inverter PI6 (i.e., the output voltage of the second tuning circuit 112) is identical to the waveform control signal. That is, the waveform of the second tuning signal is the same as the waveform control signal input from the waveform control signal input terminal S2. For example, assume that the waveform control signal input to the waveform control signal input terminal S2 is of frequency f _S2 Pulse width W _S2 Then the second tuning circuit 112 outputs a square wave ofIs also a second tuning signal of frequency f _S2 Pulse width W _S2 Is a square wave of (c). And then the second tuning signal can be adjusted by adjusting the frequency and the pulse width of the waveform control signal.

That is, the second tuning circuit 110 provided in the embodiment of the present application may generate the second tuning signal with a fixed pulse width and frequency under the condition of not receiving the external control signal (input dc voltage, refer to the embodiment of fig. 12), and drive the EL device to emit light in one color, or may receive the external digital signal/analog signal to adjust the frequency of the second tuning signal, thereby adjusting the frequency of the ac signal applied to the EL device by the driving circuit 11, further adjusting the light emitting color of the EL device, and increasing the versatility of the driving circuit 11.

With continued reference to fig. 7, the full-bridge drive circuit 113 includes a full-bridge output drive 1131, a P-channel MOSFET M2 (first P-channel MOSFET), a P-channel MOSFET M4 (second P-channel MOSFET), an N-channel MOSFET M3 (first N-channel MOSFET), and an N-channel MOSFET M5 (second N-channel MOSFET), wherein the circuit composed of the P-channel MOSFET M2, the P-channel MOSFET M4, the N-channel MOSFET M3, and the N-channel MOSFET M5 is referred to as a full-bridge circuit. The full-bridge output driver 1131 is a circuit/chip for driving a full-bridge circuit, the input terminals of the full-bridge output driver 1131 include a control terminal S113 and a voltage terminal V113, and the output terminals include an output terminal Q1, an output terminal Q2, and an output terminal And output terminal->Wherein the control port S113 is connected to the output end of the second tuning circuit 112 (the output end of the sixth inverter PI 6), the voltage terminal V113 is connected to the output end of the booster circuit 111 (the cathode of the diode D), the output terminal Q1 is connected to the gate of the P-channel MOSFET M2, the output terminal Q2 is connected to the gate of the N-channel MOSFET M3, and the output terminal>Gate electrode of P-channel MOSFET M4Connection, output terminal->The source of the P-channel MOSFET M2 is connected to the output terminal (cathode of the diode D) of the booster circuit 111, the drain is electrically connected to the source of the N-channel MOSFET M3, the drain of the N-channel MOSFET M3 is grounded, the source of the MOSFET M3 and/or the drain of the P-channel MOSFET M2 is electrically connected to the voltage output terminal OUT1, the source of the P-channel MOSFET M4 is connected to the output terminal (cathode of the diode D) of the booster circuit 111, the drain is electrically connected to the source of the N-channel MOSFET M5, the drain of the N-channel MOSFET M5 is grounded, and the source of the MOSFET M5 and/or the drain of the P-channel MOSFET M4 is electrically connected to the voltage output terminal OUT 2.

When the control terminal 113 receives the second tuning signal and is active (the square wave is in the high level period), the full-bridge output driver 1131 outputs the high level to the output terminals Q1 and Q2 and outputs the high level to the output terminals And output terminal->Outputting a low level so that the P-channel MOSFET M2 and the N-channel MOSFET M5 are turned on, the P-channel MOSFET M4 and the N-channel MOSFET M3 are turned off, and the voltage between the output terminal OUT1 and the output terminal OUT2 is V _C The method comprises the steps of carrying out a first treatment on the surface of the When the control terminal 113 receives the second tuning signal being inactive (the square wave is in the low level period), it outputs a low level to the output terminal Q1 and the output terminal Q2, and is +.>And output terminal->Outputting a high level to turn off the P-channel MOSFET M2 and the N-channel MOSFET M5 and turn on the P-channel MOSFET M4 and the N-channel MOSFET M3, wherein the voltage between the output terminal OUT1 and the output terminal OUT2 is-V _C . That is, an alternating current signal between the output terminal OUT1 and the output terminal OUT2U _D The waveform of (a) is the same as the frequency of the second tuning signal, the duty ratio is the same (the pulse width is the same), the high level is V _C At low level of-V _C Is a square wave of (c).

It will be appreciated that in other embodiments, the full bridge output driver 1131 may output a low level to the output terminals Q1 and Q2 and a low level to the output terminals when the control terminal 113 receives the second tuning signal active (during the high level of the square wave)And output terminal->Outputting a high level to turn off the P-channel MOSFET M2 and the N-channel MOSFET M5 and turn on the P-channel MOSFET M4 and the N-channel MOSFET M3, wherein the voltage between the output terminal OUT1 and the output terminal OUT2 is-V _C The method comprises the steps of carrying out a first treatment on the surface of the When the control terminal 113 receives the second tuning signal being inactive (the square wave is in the low level period), it outputs a high level to the output terminal Q1 and the output terminal Q2, and is +.>And output terminal->Outputting a low level so that the P-channel MOSFET M2 and the N-channel MOSFET M5 are turned on, the P-channel MOSFET M4 and the N-channel MOSFET M3 are turned off, and the voltage between the output terminal OUT1 and the output terminal OUT2 is V _C . That is, the alternating current signal U between the output terminal OUT1 and the output terminal OUT2 _D Is the same as the frequency of the second tuning signal, opposite to the waveform, and has a high level of V _C At low level of-V _C Is a square wave of (c).

It will be appreciated that in some embodiments, the ground in each of the circuits in the drive circuit 11 is connected to the ground terminal GND.

The driving circuit 11 shown in fig. 7 can drive the EL device by square wave ac signals, so that energy consumption can be reduced, and the endurance of the electronic equipment using the driving circuit 11 to drive the EL device can be improved. In addition, the devices in the driving circuit 11 are small, and devices such as transformers which occupy a large amount of space are not used, so that the device is easy to miniaturize and is beneficial to reducing the volume of electronic equipment. For example, referring to fig. 15, the foregoing driving circuit 11 may be packaged as the driving chip 11C shown in fig. 15, the driving chip 11C includes terminals including a voltage control signal input terminal S1, a direct current voltage input terminal VDD, a waveform control signal input terminal S2, a ground input terminal GND, and an output terminal including an output terminal OUT1 and an output terminal OUT2, and the chip has a length and a width of about 5mm, and is small in size, facilitating miniaturization of electronic devices.

In addition, the waveforms and frequencies of the first tuning signal and the second tuning signal can be adjusted by combining the analog signal, the digital signal, the analog signal and the digital signal, so that the brightness and the color of the EL device can be adjusted, the driving circuit 11 can be suitable for different scenes, and the universality of the driving circuit 11 is improved

Optionally, in some embodiments, the inductance value of the inductor L is 220 μh, the capacitance value of the capacitor C2 is 0.1 μf (100V), the resistance value of the resistor R1 is 330kΩ, and the resistance value of the resistor R2 is 1mΩ. The capacitance value of the capacitor C1 is 13pF, and the capacitance value of the capacitor C3 is 650pF.

It will be appreciated that the configuration of the driving circuit 11 shown in fig. 7 is merely an example, and in other embodiments, the driving circuit 11 may include more or fewer devices, merge or split portions of devices, and replace portions of devices, which are not limited herein.

For example, in some embodiments, referring to fig. 16A, the driving circuit 11 may not include the first tuning circuit 110, but directly connect the voltage control input terminal S1 with the gate of the MOSFET M1, so that the processor of the smart band 1 may directly input the voltage control signal to the gate of the MOSFET M1 through the voltage control input terminal S1 to adjust the driving electric signal U output by the driving circuit 11 _D Is a peak of (c).

For another example, in some embodiments, referring to fig. 16B, the driving circuit 11 may not include the second tuning circuit 112, but the waveform control input terminal S2 may be directly and entirelyThe control terminal 113 of the bridge output drive 1131 is connected, so that the processor of the smart band 1 can directly input a waveform control signal to the full bridge output drive 1131 through the waveform control input terminal S2 to adjust the driving electric signal U output by the driving circuit 11 _D Is a frequency of (a) is a frequency of (b).

For another example, in some embodiments, referring to fig. 16C, the driving circuit 11 may not include the first tuning circuit 110 and the second tuning circuit 112, but directly connect the voltage control input terminal S1 with the gate of the MOSFET M1, so that the processor of the smart band 1 may directly input the voltage control signal to the gate of the MOSFET M1 through the voltage control input terminal S1 to adjust the driving electric signal U output by the driving circuit 11 _D Further adjusting the brightness of the EL device; the waveform control input terminal S2 is directly connected with the control terminal 113 of the full-bridge output drive 1131, so that the processor of the smart bracelet 1 can directly input the waveform control signal to the full-bridge output drive 1131 through the waveform control input terminal S2 to regulate the driving electric signal U output by the driving circuit 11 _D And thus adjusts the color of the EL device.

For another example, in some embodiments, some of the circuitry in the drive circuit 11 may be replaced, such as replacing the first tuning circuit and/or the second tuning circuit.

For another example, the full-bridge circuit formed by the P-channel MOSFET M2, the P-channel MOSFET M4, the N-channel MOSFET M3, and the N-channel MOSFET M5 may be a full-bridge circuit formed by other forms, such as replacing the corresponding MOSFETs with an electron Triode (Triode), a bipolar transistor BJT (Bipolar Junction Transistor), a J-type field effect transistor Junction gate FET (Field Effect Transistor), and a V-type trench field effect transistor VMOS (Vertical Metal Oxide Semiconductor).

For another example, the first tuning circuit 110 or the second tuning circuit 112 may be replaced by other tuning circuits. For example, in some embodiments, the number of inverters in the first tuning circuit 110 or the second tuning circuit 112 may be increased, thereby decreasing the frequency of the first tuning circuit 110 or the second tuning circuit 112. Specifically, the first tuning circuit 110 or the second tuning circuit 112 may be replaced by the tuning circuit 120 shown in fig. 17, and referring to fig. 17, the tuning circuit 120 may include n inverters (where n is smaller, for example, n <20, n is odd, and where n is larger, for example, n >20, n is either odd or even).

The embodiment of the present application also provides an EL device driving apparatus 2, and referring to fig. 18, the EL device driving apparatus 2 includes a processor 21 and a driving circuit 22. The processor 21 is configured to send a voltage control signal and/or a waveform control signal to the driving circuit 22, so as to adjust the peak value and the frequency of the square wave ac electric signal output by the driving circuit 22.

The processor 21 may include at least one processor unit, such as a digital signal processing (Digital Signal Processor, DSP), a micro control unit (Micro Control Unit, MCU), and a microprocessor unit (Micro Processor Unit, MPU), among others.

The driving circuit 22 may include at least one of any of the driving circuits provided in the foregoing embodiments, for example, the driving circuit 11.

Since the EL device driving apparatus 2 can drive the EL device by square wave, the energy consumption of the EL device is saved, and the endurance of the electronic device which uses the driving apparatus 2 to drive the EL device can be improved.

The embodiment of the application also provides electronic equipment, which comprises at least one driving circuit, at least one EL device and a processor, wherein the driving circuit, the at least one EL device and the processor are provided for sending a voltage control signal and/or a waveform control signal to the driving circuit so that the driving circuit drives the EL device to emit light.

Because the electronic equipment drives the EL device through the square wave, the energy consumption of the EL device is saved, and the cruising ability of the electronic equipment can be improved.

It will be appreciated that the electronic devices provided by embodiments of the present application include, but are not limited to, wearable devices (e.g., smart watches, smart bracelets, wearable medical devices, etc.), cell phones, tablet computers, head mounted displays, mobile email devices, portable game consoles, portable music players, reader devices, and the like.

Further, the embodiment of the application also provides a driving method of the EL device, which is applied to the electronic equipment comprising the processor, the driving circuit provided by the previous embodiments and the EL device. The following description will take the foregoing smart band 1 as an example.

Specifically, fig. 19 shows a flow diagram of a method of driving an EL device, according to some embodiments of the application. As shown in fig. 19, the flow includes:

s1901: the processor 10 generates and transmits a voltage control signal and/or a waveform control signal to the driving circuit 11.

When detecting that the user adjusts the color and/or brightness of the EL device of the smart watch 1, the smart bracelet 1 generates a corresponding voltage control signal and a corresponding waveform control signal according to the corresponding relation between the preset voltage and the brightness and the corresponding relation between the preset frequency and the color. For example, the processor 10 may generate a voltage control signal having a duty cycle gradually increasing from a high to a low and then gradually increasing from a low to a high, or may generate a waveform control signal having a frequency gradually increasing from a high to a low and then gradually increasing from a low.

It will be appreciated that in some embodiments, the preset voltage-luminance correspondence, preset frequency-color correspondence may be obtained by experiment according to the hardware parameters of the driving circuit 11 and the characteristics of the EL device.

S1902: the driving circuit 11 adjusts the peak value and/or the frequency of the driving electric signal according to the voltage control signal and/or the waveform control signal.

The driving circuit 11 adjusts the peak value and/or the frequency of the driving electrical signal according to the voltage control signal and/or the waveform control signal, and the specific adjustment manner can refer to the embodiments of fig. 7 to 14, which are not described herein.

For example, when the duty ratio of the voltage control signal is gradually increased from a high level to a low level and then gradually increased from a low level to a high level, the peak value of the driving electric signal is gradually increased from a high level to a low level and then gradually increased from a low level to a high level. For example, when the frequency of the waveform control signal is gradually changed from high to low and then gradually changed from low to high, the frequency of the driving electric signal is gradually changed from high to low and then gradually changed from low to high.

S1903: the EL device 12 emits light according to the peak value and frequency of the driving electric signal.

The EL device emits light according to the peak value and frequency of the driving electric signal.

For example, when the voltage of the driving electric signal is gradually increased from a small value to a large value, the light emission luminance of the EL device 12 gradually becomes dark from bright, and gradually becomes dark, thereby forming a breathing lamp effect. For another example, when the frequency of the driving electric signal gradually increases from low to high, and then gradually increases from low, the emission color of the EL device 12 gradually changes.

The foregoing has outlined rather broadly the more detailed description of embodiments of the invention, wherein the principles and embodiments of the invention are explained in detail using specific examples, the above examples being provided solely to facilitate the understanding of the method and core concepts of the invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.

Claims

1. An electronic device, comprising:

a controller for generating a control signal;

the driving circuit outputs square wave alternating current signals according to the control signals generated by the controller;

the electroluminescent device is used for emitting light according to the square wave alternating current signal output by the driving circuit, the brightness of the light emitted by the electroluminescent device is determined by the high electric signal value of the square wave alternating current signal, and the color of the light emitted by the electroluminescent device is determined by the frequency of the square wave alternating current signal.

2. The electronic device of claim 1, wherein the high and low electrical signal values of the square wave ac electrical signal, the frequency of the square wave ac electrical signal, are determined based on the control signal.

3. The electronic device of claim 2, wherein the control signal comprises a voltage control signal, and the drive circuit comprises:

the first tuning circuit is used for receiving the voltage control signal and outputting first tuning signals with different duty ratios according to the voltage control signal;

and the boosting circuit is used for boosting the first voltage input into the boosting circuit into a second voltage according to the duty ratio of the first tuning signal, wherein the second voltage is increased along with the increase of the duty ratio of the first tuning signal, and the high electric signal of the square wave alternating current signal is the same as the second voltage.

4. The electronic device of claim 3, wherein the control signal further comprises a waveform control signal, and the drive circuit further comprises:

the second tuning circuit is used for receiving the waveform control signal and outputting second tuning signals with different frequencies according to the waveform control signal;

the full-bridge driving circuit is used for receiving the second tuning signal and the second voltage, outputting the square wave alternating current signal according to the frequency and the duty ratio of the second tuning signal, wherein the frequency of the square wave alternating current signal is the same as the frequency of the second tuning signal, the duty ratio of the square wave alternating current signal is the same as the duty ratio of the second tuning signal, the high electric signal value of the square wave alternating current signal is the second voltage, and the low electric signal value is the reverse voltage of the second voltage.

5. The electronic device of claim 4, wherein the full-bridge drive circuit outputs a second voltage when the second tuning signal is a high electrical signal, and outputs an inverted voltage of the second voltage when the second tuning signal is a low electrical signal; or outputting a second voltage when the second tuning signal is a low electrical signal, and outputting an inverted voltage of the second voltage when the second tuning signal is a high electrical signal.

6. The electronic device of claim 4, wherein the first tuning circuit comprises: a first inverter, a second inverter, a third inverter, and a first capacitor;

the input end of the first inverter is connected with the output end of the third inverter, the output end of the first inverter is connected with the input end of the second inverter, the output end of the second inverter is connected with the input end of the third inverter, and one end of the first capacitor is connected with the output end of the first inverter and the other end of the first capacitor is grounded;

and the output end of the first inverter is used for receiving the voltage control signal, and the output end of the third inverter is used for outputting a first tuning signal to the boost circuit.

7. The electronic device of claim 6, wherein the output of the first inverter is further coupled to one end of a first resistor, and the other end of the first resistor is configured to receive the voltage control signal.

8. The electronic device according to claim 6 or 7, characterized in that the booster circuit comprises: a MOSFET, an inductor, a diode, and a second capacitor;

the grid electrode of the MOSFET is used for receiving the first tuning signal, the source electrode of the MOSFET is grounded and connected with one end of the second capacitor, the drain electrode of the MOSFET is connected with one end of the inductor and the anode of the diode, the other end of the inductor is used for receiving the first voltage, and the cathode of the diode is connected with the other end of the second capacitor;

the cathode of the diode is used for outputting the second voltage to the full-bridge driving circuit.

9. The electronic device of any one of claims 4-8, wherein the second tuning circuit comprises: a fourth inverter, a fifth inverter, a sixth inverter, and a third capacitor;

the input end of the fourth inverter is connected with the output end of the sixth inverter, the output end of the fourth inverter is connected with the input end of the fifth inverter, the output end of the fifth inverter is connected with the input end of the sixth inverter, one end of the third capacitor is connected with the output end of the fourth inverter, and the other end of the third capacitor is grounded;

And an output terminal of the fourth inverter is configured to receive the waveform control signal, and an output terminal of the sixth inverter is configured to output the second tuning signal to the full-bridge driving circuit.

10. The electronic device of claim 9, wherein the output of the fourth inverter is further coupled to one end of a second resistor, and the other end of the second resistor is configured to receive the waveform control signal.

11. The electronic device of claim 9 or 10, wherein the full-bridge drive circuit comprises: full bridge output drive, first P-channel MOSFET, second P-channel MOSFET, first N-channel MOSFET, and second N-channel MOSFET;

the full-bridge output driver comprises a control signal input end, a voltage input end, a first output end, a second output end, a third output end and a fourth output end, wherein the control signal input end is used for receiving the second tuning signal, and the voltage input end is used for receiving the second voltage;

the first output end is connected with the grid electrode of the first P-channel MOSFET, the second output end is connected with the grid electrode of the first N-channel MOSFET, the third output end is connected with the grid electrode of the second P-channel MOSFET, the fourth output end is connected with the grid electrode of the first N-channel MOSFET, the source electrode of the first P-channel MOSFET and the source electrode of the second P-channel MOSFET are used for receiving the second voltage, the source electrode of the first N-channel MOSFET and the drain electrode of the second N-channel MOSFET are grounded, the drain electrode of the first P-channel MOSFET is connected with the source electrode of the first N-channel MOSFET, the drain electrode of the second P-channel MOSFET is connected with the source electrode of the second N-channel MOSFET, and the drain electrode of the first P-channel MOSFET and the drain electrode of the second P-channel MOSFET are used for outputting the square wave alternating current signal to the electroluminescent device;

The full-bridge output driver outputs a voltage for turning on the first P-channel MOSFET to the first output terminal, a voltage for turning off the first P-channel MOSFET to the second output terminal, a voltage for turning off the second P-channel MOSFET to the third output terminal, a voltage for turning on the second N-channel MOSFET to the fourth output terminal, and a voltage for turning off the first P-channel MOSFET to the first output terminal, a voltage for turning on the first N-channel MOSFET to the second output terminal, and a voltage for turning off the second P-channel MOSFET to the third output terminal when the second tuning signal is a high signal; or alternatively

The full-bridge output driver outputs a voltage for turning on the first P-channel MOSFET to the first output terminal, a voltage for turning off the first N-channel MOSFET to the second output terminal, a voltage for turning off the second P-channel MOSFET to the third output terminal, a voltage for turning on the second N-channel MOSFET to the fourth output terminal, and a voltage for turning off the first P-channel MOSFET to the first output terminal, a voltage for turning on the first N-channel MOSFET to the second output terminal, and a voltage for turning off the second P-channel MOSFET to the fourth output terminal when the second tuning signal is a low electrical signal.