TWM522513U - Power control device - Google Patents

Description

Power control device

The present invention relates to a power control device, and more particularly to a power control device for a protection circuit module for controlling a surge current.

Almost all circuits operating inside an electronic device use DC power as a power source, and energy storage components are required in the circuit. Therefore, there is a capacitor (referred to as a capacitor for short). When the power is turned on (or called the power-on, the initial start of the circuit), the initial voltage of the capacitor is zero, which is approximately short-circuited, so a large transient current is generated, which is the surge current. This surge current can cause noise, even cause malfunction of the electronic circuit, and cause component failure or malfunction.

At present, the conventional method for solving the surge current is roughly classified into the first type, and a series resistor is connected to the power path to limit the current. However, the resistance causes the loss to rise, or by adding a bypass (bypass) line to bypass the resistor after power-on, which increases the complexity of the line. The second type is the slow-start mode, which allows the load switch to go from the off (or off) state to the on (or open) state for a longer period of time, that is, the impedance of the load switch is infinite (completely Turn off) Slowly transition to near zero (fully turned on). This method creates a problem that the transition time of the load switch is not easily controlled.

The present invention provides a power control device, in particular, a power control device for a protection circuit module for controlling a surge current, which can reduce or effectively suppress a surge when the line is turned on (or is called a power-on or an initial circuit start). Current.

The present embodiment provides a power control device for controlling a surge current, which includes a protection circuit module for controlling a surge current, including a control unit and a load open turn off. The control unit generates a start signal. The load switch has a first end, a second end, and a control end. The first end of the load switch receives the DC input voltage, and the second end is coupled to the load control module having the load capacitance, and the control end is coupled to the control unit and controlled by the start signal. When the circuit is initially started, the start signal is a pulse width modulation signal that lasts for a preset time.

In an embodiment, the load control module is a boost circuit or a buck circuit or a buck-boost circuit.

In an embodiment, the load switch comprises a P-type metal oxide semiconductor field effect transistor.

In an embodiment, the protection circuit module for controlling the surge current further includes an enable switch. The enable switch is coupled between the gate of the solid state load switch and the ground, and the control end of the enable switch receives the start signal.

In an embodiment, the load switch comprises an N-type metal oxide semiconductor field effect transistor.

In an embodiment, the control unit is a microcontroller.

In an embodiment, the control unit is implemented as an integrated circuit module.

In one embodiment, the control unit is a microcontroller or integrated circuit module that produces a variable frequency pulse width modulation signal as the enable signal.

In one embodiment, the control unit is a microcontroller or integrated circuit module that generates a pulse width modulation signal with a duty cycle variable as the enable signal.

In one embodiment, the control unit is a microcontroller or integrated circuit module that generates a pulse width modulation signal with a gradually increasing duty cycle as the enable signal.

In summary, the present embodiment provides a power control device, including a protection circuit module for controlling a surge current, and using a pulse width modulation method to control a start signal of a load switch to reduce a surge current and achieve a suppression surge. The purpose of the current can also avoid noise and malfunction caused by the surge current.

That is, the pulse width modulation method is used, and the frequency and duty cycle of the load switch are changed to control the magnitude of the surge current to achieve the purpose of suppressing the surge current.

In order to further understand the features and technical contents of this creation, please refer to the following detailed description and drawings of this creation, but these descriptions and drawings are only used to illustrate this creation, not the right to this creation. The scope is subject to any restrictions.

100‧‧‧Power control unit

1‧‧‧Protection circuit module for controlling surge current

11‧‧‧Load switch

A‧‧‧first end

B‧‧‧second end

c‧‧‧Control terminal

12‧‧‧Control unit

EN‧‧‧ start signal

Vin‧‧‧DC input voltage

GND‧‧‧ Grounding

2‧‧‧Load Control Module

CL‧‧‧ load capacitance

21‧‧‧Load circuit

111‧‧‧P type metal oxide semiconductor field effect transistor

112‧‧‧Enable switch

3‧‧‧Boost circuit

Vo‧‧‧ output voltage

L1‧‧‧Inductance

D1‧‧‧ diode

Q1‧‧‧ switch

C1‧‧‧ capacitor

T‧‧‧Preset time

I‧‧‧current

EN1‧‧‧ start signal

I1‧‧‧ Current

12'‧‧‧Microcontroller or integrated circuit module

Q2‧‧‧Load switch

Cout‧‧‧ output capacitor

Vout‧‧‧ output voltage

4‧‧‧Load Control Module

1 is a block diagram of load switch control of a protection circuit module for controlling a surge current of a power control device according to an embodiment of the present invention.

2 is a circuit diagram of a booster circuit as a load control module in which a protection circuit module for controlling a surge current of a power supply control device is provided in the present embodiment.

Fig. 3 is a waveform diagram of a conventional start signal and a booster circuit using a slow start mode.

4 is a waveform diagram of a start signal of a protection circuit module for controlling a surge current and a current of a booster circuit according to an embodiment of the present invention.

FIG. 5 is a waveform diagram showing a start signal of a protection circuit module for controlling a surge current of a power supply control device and a current of a booster circuit according to another example of the present invention.

6 is a circuit diagram of a protection circuit module for controlling a surge current implemented by a microcontroller or an integrated circuit module of another power supply control device according to another example of the present invention.

[Embodiment of Protection Circuit for Controlling Surge Current]

Please refer to FIG. 1 , which is a structural diagram of load switch control for controlling a surge current provided by an embodiment of the present power control device 100 . The protection circuit module 1 for controlling the surge current includes the control unit 12 and the load switch 11 in the present embodiment. The protection circuit module 1 for controlling the surge current transmits the DC input voltage Vin to the load control module 2. Therefore, the protection circuit module 1 for controlling the surge current in the present embodiment is exemplified by a load switch control circuit. For the protection circuit module 1 for controlling the surge current, the load control module 2 includes a load capacitance CL and a load circuit 21. In Figure 1, the load capacitance CL is specifically drawn to highlight when the circuit is started (or turned on) due to The capacitance of the load control module 2 itself needs to receive current to store the charge. However, this creation does not limit the connection relationship between the capacitance of the load control module and the load switch 11. The capacitance of the load control module may not be directly connected to the load switch 11, and may be connected to the load switch 11 through other circuit components (inductors or resistors, etc.). Please refer to the description of the embodiment of FIG. 2. In addition, the load switch 11 described in the present application is a solid state switch implemented by semiconductor technology, for example, including a transistor switch, but the present invention does not limit the implementation of the load switch 11.

Referring again to Figure 1, control unit 12 generates an enable signal EN. The load switch 11 has a first end a, a second end b and a control end c. The first end a of the load switch 11 receives the DC input voltage Vin, and the second end b is coupled to the load control module 2 having the load capacitance CL. The control terminal c is coupled to the control unit 12 and controlled by the start signal EN.

When the protection circuit module 1 that controls the surge current has not been activated, the DC input voltage Vin cannot be transmitted to the load control module 2. When the protection circuit module 1 for controlling the surge current is initially activated, the start signal EN is a pulse width modulation (PWM) signal for a preset time T. After the preset time T, the start signal continues to remain high (High), allowing the load control module to obtain power for normal operation. This preset time T is variable and can be determined according to the actual application. For example, it depends on the magnitude of the capacitance of the load control module 2 (such as the capacitance value of the load capacitance CL), but the present creation is not limited thereto. For a detailed implementation of the enable signal EN, please refer to the subsequent further description.

According to the concept of the present creation, in an embodiment, the enable signal EN can be, for example, a variable frequency pulse width modulation signal, but the present creation is not limited thereby. In another embodiment, the enable signal EN may be a pulse width modulated signal having a duty cycle variable. In yet another embodiment, the enable signal EN is a pulse width modulated signal with a gradually increasing duty cycle, as will be further described below.

According to the circuit architecture of FIG. 1, the load control module is described by taking a boost circuit 3 as an example. In FIG. 2, the load switch 11 includes a P-type metal oxide semiconductor field effect transistor 111 and an enable switch 112. Figure 2 shows The circuit of the load switch 11 is only one of the exemplary examples to help illustrate, and is not intended to limit the creation. In other embodiments, the load control module can also be a buck circuit or a buck-boost circuit.

Next, the load switch 11 of FIG. 2 will be further described. The source and collector of the P-type MOSFET 111 are the first end a and the second end b of the load switch 11, respectively. The enable switch 112 is coupled between the 111 gate of the P-type MOSFET and the ground GND. In the present embodiment, the enable switch 112 is an N-type metal oxide semiconductor field effect transistor, but the present creation is not limited thereto. The control terminal (e.g., the gate) of the enable switch 112 receives the enable signal EN from the control unit 12 (see Fig. 1).

Next, the booster circuit 3 of FIG. 2 will be described. The booster circuit 3 is a typical booster circuit for boosting the DC input voltage Vin to a higher voltage output voltage Vo. The boosting circuit 3 includes an inductor L1, a diode D1, a switch Q1 (in the FIG. 2, an N-type metal oxide semiconductor field effect transistor), and a capacitor C1. One end of the inductor L1 receives the DC input voltage Vin through the load switch 11. The other end of the inductor is connected to the anode of the diode D1. The switch Q1 is connected between the anode of the diode D1 and the ground GND. The capacitor C1 is connected between the cathode of the diode D1 and the ground GND, and the end of the cathode of the diode D1 connected to the capacitor C1 serves as an output terminal to provide an output voltage Vo. Those skilled in the art should be able to easily understand the working mode of the booster circuit 3, and will not be described here.

When the circuit is just started, the load switch 11 supplies the input voltage Vin to the boosting circuit 3, and the current flowing through the inductor L1 is represented by I. Referring to FIG. 3, the conventional slow-start mode is to directly raise the enable signal EN to a high level (High), so that the current flowing through the inductor L1 passes through the diode D1 to charge the capacitor C1. The charge has not been stored, so that during the charge accumulation of the capacitor C1, the current I forms an inrush current. In FIG. 3, in the case where the inductance L1 and the capacitance C1 are known, with the circuit architecture of FIG. 2, the maximum value of the surge current of the present embodiment is exemplified by 38.0 amps. Then according to the control method of this creation, the electricity of Figure 2 In the case of a road structure and identical circuit elements, the start signal EN is made to be a pulse width modulation signal for a preset time T, see FIG. As is apparent from Figure 4, the current I is significantly less than the original 38.0 amps and the current maximum is reduced to 7.50 amps.

In other words, this creation is to switch the start signal EN multiple times during startup to avoid excessive transient currents. Further, according to the control method of the present creation, the frequency and the duty cycle of the pulse width signal as the start signal EN can be adjusted, and the present creation is not limited. After the preset time T, the enable signal EN is at a high level (High), indicating that the circuit has completed startup and starts normal operation. And in the normal operation of the circuit, the start signal EN is continuously maintained at a high level (High).

FIG. 5 is a waveform diagram of a start signal of a protection circuit for controlling a surge current and a current of a booster circuit provided by another example of the present invention. The enable signal EN1 in Fig. 5 is a pulse width modulation signal whose duty cycle is gradually increased. According to the pulse width modulation signal whose duty cycle is gradually increased, the current I1 flowing to the load (for example, the current I of FIG. 2) can maintain its maximum value in each duty cycle not exceeding a set upper limit, for example, each The maximum value of current I1 in the duty cycle is approximately equal, as shown in 5. It should be noted that the startup signal of FIG. 5 is only an exemplary implementation of the startup signal EN for the purpose of helping to demonstrate that the current level of the load control module can be performed when the protection circuit module for controlling the surge current is initially started. Adjustment, but this creation is not limited. According to a similar principle, when the frequency of the pulse width modulation signal as the start signal EN is adjusted, the magnitude of the current input to the load control module at the time of starting can also be adjusted.

Next, according to the foregoing FIG. 1, the control unit 12 of the present invention may be a microcontroller, and can also be implemented by an integrated circuit module (IC) or a wafer. FIG. 6 is another example of the present invention. The control unit 12' is exemplified by a microcontroller or an integrated circuit module for implementing a circuit diagram of the load switch control circuit, but is not limited to the control unit of the present invention. When the control unit 12' transmits the DC input voltage Vin to the load control module 4 through the control load switch Q2. When the protection circuit module for controlling the surge current of FIG. 6 is just started, the output capacitor Cout needs to be included (even including the load control module itself). Some capacitors are charged. According to the control method described above, the transient surge current of the output capacitor Cout and the capacitor (not shown in FIG. 6) including the load control module 4 itself can be charged. Decrease in magnitude.

[Possible effects of the examples]

In summary, the protection circuit module for controlling the surge current provided by the present embodiment uses the pulse width modulation method to control the start signal of the load switch to control the magnitude of the surge current and achieve the purpose of suppressing the surge current. It also avoids noise and malfunction caused by surge current. Moreover, by changing the frequency of switching and the duty cycle, the magnitude of the surge current can be further controlled.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the patent of the present invention.

100‧‧‧Power control unit

1‧‧‧Protection circuit module for controlling surge current

11‧‧‧Load switch

A‧‧‧first end

B‧‧‧second end

c‧‧‧Control terminal

12‧‧‧Control unit

EN‧‧‧ start signal

Vin‧‧‧DC input voltage

GND‧‧‧ Grounding

2‧‧‧Load Control Module

CL‧‧‧ load capacitance

21‧‧‧Load circuit

Claims (10)

A power control device for controlling a surge current, comprising a protection circuit module for controlling a surge current, the protection circuit module for controlling a surge current comprising: a control unit for generating a start signal; and a load switch, Having a first end, a second end, and a control end, the first end receives a DC input voltage, and the second end is coupled to a load control module having a load capacitor coupled to the control unit And being controlled by the start signal; wherein, when the protection circuit module for controlling the surge current is initially started, the start signal is a pulse width modulation signal that lasts for a preset time. The power control device of claim 1, wherein the load control module is a boost circuit, a buck circuit or a buck-boost circuit. The power control device of claim 1, wherein the load switch comprises a P-type metal oxide semiconductor field effect transistor. According to the power supply control device of claim 3, the load switch further includes: a uniform energy switch coupled between a gate of the P-type MOSFET and a ground, the enable switch Receive the start signal. The power control device of claim 1, wherein the load switch comprises an N-type metal oxide semiconductor field effect transistor. The power control device of claim 1, wherein the control unit is a microcontroller. The power control device of claim 1, wherein the control unit is implemented by an integrated circuit module. The power control device of claim 1, wherein the control unit is a microcontroller or an integrated circuit module that generates a variable frequency pulse width modulation signal as a start signal. The power control device of claim 1, wherein the control unit is a microcontroller or an integrated circuit module that generates a pulse width modulation signal with a duty cycle variable as a start signal. The power control device of claim 1, wherein the control unit is a microcontroller or an integrated circuit module that generates a pulse width modulation signal whose duty cycle is gradually increased as a start signal.