CN108768353B

CN108768353B - Driving circuit

Info

Publication number: CN108768353B
Application number: CN201810549420.3A
Authority: CN
Inventors: 陈启仁
Original assignee: Qisda Optronics Suzhou Co Ltd; Qisda Corp
Current assignee: Qisda Optronics Suzhou Co Ltd; Qisda Corp
Priority date: 2018-05-31
Filing date: 2018-05-31
Publication date: 2022-05-17
Anticipated expiration: 2038-05-31
Also published as: CN108768353A

Abstract

The invention discloses a driving circuit, which is used for driving a first integrated chip, wherein the first integrated chip is provided with an input port and an enabling port, the first integrated chip is provided with a first enabling voltage, and the driving circuit comprises a voltage providing unit and a protection unit. The voltage supply unit is coupled with the input port and used for supplying a first input voltage; the protection unit is coupled with the output end of the voltage supply unit and is provided with a first control node which is coupled with the enabling port; when the first input voltage reaches the first threshold voltage, the first node voltage reaches a first enabling voltage, and the first integrated chip works. The invention can avoid the risk of damage to the first integrated chip and the electric elements thereof caused by the instant change of the first input voltage.

Description

Driving circuit

Technical Field

The present invention relates to a driving circuit, and more particularly, to a driving circuit having functions of protecting an integrated chip and an electric element.

Background

A pulse width modulation chip (PWM IC) generally has an Enable port (Enable pin), and a fixed voltage level is usually set for the Enable port to be linked with an input voltage Vin, and the fixed voltage level may be referred to as an Enable voltage. When the input voltage Vin reaches a certain level, the voltage at the Enable port (Enable pin) reaches the Enable voltage, so that the pwm chip is enabled, the pwm chip starts to operate, and the electrical component (such as a metal-oxide semiconductor field effect transistor MOSFET) connected to the pwm chip starts to operate.

Referring to fig. 1, fig. 1 is a schematic diagram of a driving circuit in the prior art. In the driving circuit 100 ', when the input voltage Vin' reaches 6.8V, the voltage at the enable port EN 'of the pwm chip IC 1' reaches 1.26V, which reaches the enable voltage of the pwm chip IC1 ', so that the pwm chip IC 1' starts to operate. In practical operation, when the input voltage Vin 'is high (e.g., 20V) and the enable voltage is low (e.g., 1.26V), the current flowing through the powered device Q1' (e.g., MOSFET) coupled to the pwm chip IC1 'will suddenly increase when the input voltage Vin' changes momentarily. When some connectors in the power supply circuit are in poor contact or have an instantaneous power failure, the input voltage Vin 'may have an instantaneous change of dropping from 20V to 7V and then rising back to 20V, because the voltage at the enable port EN' can still reach the enable voltage when the input voltage Vin 'is 7V, the clock pulse modulation chip IC 1' continues to operate, and in order to maintain normal operation, the duty ratio of the pulse width modulation chip IC1 'is increased, for example, to more than 90%, and at this time, the duty ratio of the electric element Q1' connected with the pulse width modulation chip IC1 'is kept consistent with that of the pulse width modulation chip IC 1'. When the input voltage Vin ' is instantaneously returned to 20V from 7V, the pwm chip IC1 ' needs some response time to reduce the duty ratio, but during this period, the power consumption device Q1 ' will be subjected to a large instantaneous current, so that there is a risk that the pwm chip IC1 ' itself and the power consumption device Q1 ' are damaged.

Disclosure of Invention

The invention aims to provide a driving circuit which is provided with a protection unit so as to protect an integrated chip and electric elements thereof in the circuit and avoid the problem that the integrated chip and the electric elements are damaged or even damaged due to transient large current which may occur.

In order to achieve the above object, the present invention provides a driving circuit for driving a first ic, the first ic having an input port and an enable port, the first ic having a first enable voltage, the driving circuit comprising:

a voltage providing unit coupled to the input port, the voltage providing unit being configured to provide a first input voltage; and

the protection unit is coupled with the output end of the voltage supply unit and is provided with a first control node which is coupled with the enabling port and defines the voltage at the first control node as a first node voltage;

when the first input voltage reaches the first threshold voltage, the first node voltage reaches the first enabling voltage, and the first integrated chip works;

when the required voltage of the first integrated chip is a second required voltage, the second required voltage is smaller than the first required voltage, the driving circuit determines a second working mode corresponding to the second required voltage, and further determines that the threshold input voltage of the first integrated chip is a second threshold voltage, the second threshold voltage is smaller than the first threshold voltage, when the first input voltage reaches the second threshold voltage, the first node voltage reaches the first enabling voltage, and the first integrated chip works.

As an optional technical solution, when the driving circuit is in the first operating mode, if the first input voltage is less than the first threshold voltage, the first node voltage is less than the first enable voltage, and the first integrated chip does not operate; when the driving circuit is in the second working mode, if the first input voltage is smaller than the second threshold voltage, the first node voltage is smaller than the first enabling voltage, and the first integrated chip does not work.

As an optional technical solution, the protection unit includes:

a first voltage division unit having a first end and a second end opposite to each other, the first end being coupled to the output end of the voltage supply unit, the second end being coupled to the first control node, and defining the voltage at the two ends of the first voltage division unit as a first divided voltage; and

the second voltage division unit is connected with the first voltage division unit in series, the second voltage division unit is provided with a third end and a fourth end which are opposite, the third end is coupled with the second end, the fourth end is grounded, the voltages at the two ends of the second voltage division unit are second divided voltages, the sum of the first divided voltages and the second divided voltages is equal to the first input voltage, the first node voltage is equal to the second divided voltages, and when the required voltage of the first integrated chip is different, the ratio of the second divided voltages to the first input voltage is different.

As an optional technical solution, if the effective resistance value of the first voltage dividing unit is a first unit resistance value, which is denoted as R1, the effective resistance value of the second voltage dividing unit is a second unit resistance value, which is denoted as R2, the first input voltage is denoted as V1, and the second voltage is denoted as VF2, then: VF2/V1 ═ R2/(R1+ R2), and when the required voltages of the first ic chip are different, the resistances of the second cells are different.

As an optional technical solution, the first voltage dividing unit includes a first number of resistors, where the first number is ≧ 1, and the second voltage dividing unit includes a second number of resistors, where the second number is ≧ 2.

As an optional technical solution, the first voltage dividing unit includes 1 resistor defined as a first resistor, a resistance value of the first resistor is a first resistance value, the resistance value of the first unit is equal to the first resistance value, the second voltage dividing unit includes 2 resistors connected in series and respectively defined as a second resistor and a third resistor, the resistance value of the second resistor is a second resistance value, and the resistance value of the third resistor is a third resistance value, wherein, when the driving circuit is in the first working mode, the resistance value of the second unit is equal to the second resistance value; when the driving circuit is in the second working mode, the resistance value of the second unit is equal to the sum of the second resistance value and the third resistance value.

As an optional technical solution, the protection unit further has a second control node, the driving circuit further includes a control unit, the control unit has a first output end, the first output end is configured to output a first level signal, the first output end is coupled to the second control node, one end of the second resistor is the third end, the other end of the second resistor is coupled to the second control node, one end of the third resistor is coupled to the second control node, and the other end of the third resistor is the fourth end, where when the driving circuit is in the first working mode, the first level signal is a low level signal, the effective resistor included in the second voltage dividing unit is the second resistor, and the resistance of the second unit is equal to the second resistance; when the driving circuit is in the second working mode, the first level signal is a high level signal, the effective resistors included in the second voltage division unit are the second resistor and the third resistor, and the resistance value of the second unit is equal to the sum of the second resistance value and the third resistance value.

As an optional technical solution, the control unit further has a first control end, the first control end is coupled to the voltage providing unit, when in use, the control unit provides a first level signal to the protection unit through the first output end according to the required voltage of the first ic chip to determine the operating mode of the driving circuit and the threshold input voltage of the first ic chip, then the control unit provides a voltage signal to the voltage providing unit through the first control end according to the required voltage, and the voltage providing unit outputs the matched first input voltage according to the voltage signal.

As an optional technical solution, the control unit further has a second control end, the second control end is coupled to the enable port of the first ic, when in use, the control unit provides a first level signal to the protection unit through the first output end according to the required voltage of the first ic to determine the operating mode of the driving circuit and the threshold input voltage of the first ic, and then the first control end outputs a high level signal.

As an optional technical solution, the first voltage dividing unit includes 1 resistor defined as a first resistor, a resistance value of the first resistor is a resistance value of the first unit, the second voltage dividing unit includes 5 resistors connected in series and respectively defined as a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, the protection unit further includes a second control node, a third control node, a fourth control node and a fifth control node, one end of the second resistor is the third terminal, the other end of the second resistor is coupled to the second control node, one end of the third resistor is coupled to the second control node, the other end of the third resistor is coupled to the third control node, one end of the fourth resistor is coupled to the third control node, the other end of the fourth resistor is coupled to the fourth control node, one end of the fifth resistor is coupled to the fourth control node, and the other end of the fifth resistor is coupled to the fifth control node, one end of the sixth resistor is coupled to the fifth control node, the other end of the sixth resistor is grounded, the driving circuit further comprises a control unit having a first control end, a first output end, a second output end, a third output end and a fourth output end, the first control end is coupled to the voltage providing unit, the first output end is coupled to the second control node, the second output end is coupled to the third control node, the third output end is coupled to the fourth control node, the fourth output end is coupled to the fifth control node, wherein,

when the required voltage of the first integrated chip is the first required voltage, the driving circuit sends a first level signal corresponding to the first required voltage through the control unit to control the first output end to output a low level signal, and the second output end, the third output end and the fourth output end to output high level signals, so that the working mode of the driving circuit is determined to be the first working mode, the threshold input voltage is further determined to be the first threshold voltage, at the moment, the resistance value of the second unit is equal to the resistance value of the second resistor, and then the control unit controls the voltage providing unit to output the first input voltage matched with the first threshold voltage;

when the required voltage of the first integrated chip is the second required voltage, the driving circuit sends a second level signal corresponding to the second required voltage through the control unit to control the first output end, the third output end and the fourth output end to output high level signals, the second output end outputs low level signals, so that the working mode of the driving circuit is determined to be the second working mode, the threshold input voltage is further determined to be the second threshold voltage, at the moment, the resistance value of the second unit is equal to the sum of the resistance values of the second resistor and the third resistor, and then the control unit controls the voltage providing unit to output the first input voltage matched with the second threshold voltage;

when the required voltage of the first integrated chip is a third required voltage, and the third required voltage is smaller than the second required voltage, the driving circuit sends a third level signal corresponding to the third required voltage through the control unit to control the first output end, the second output end and the fourth output end to output high level signals, and the third output end outputs a low level signal, so that the working mode of the driving circuit is determined to be a third working mode, and further the threshold input voltage is determined to be a third threshold voltage which is smaller than the second threshold voltage, at this time, the resistance value of the second unit is equal to the sum of the resistance values of the second resistor, the third resistor and the fourth resistor, and then the control unit controls the voltage providing unit to output the first input voltage matched with the third threshold voltage;

when the required voltage of the first integrated chip is a fourth required voltage, and the fourth required voltage is less than the third required voltage, the driving circuit sends a fourth level signal corresponding to the fourth required voltage through the control unit to control the first output terminal, the second output terminal and the third output terminal to output high level signals, and the fourth output terminal outputs low level signals, so as to determine that the working mode of the driving circuit is a fourth working mode, and further determine that the threshold input voltage is a fourth threshold voltage, and the fourth threshold voltage is less than the third threshold voltage, at this time, the resistance value of the second unit is equal to the sum of the resistance values of the second resistor, the third resistor, the fourth resistor and the fifth resistor, and then the control unit controls the voltage providing unit to output the first input voltage matched with the fourth threshold voltage;

when the required voltage of the first integrated chip is a fifth required voltage, and the fifth required voltage is less than the fifth required voltage, the driving circuit sends a fifth level signal corresponding to the fifth required voltage through the control unit to control the first output terminal, the second output terminal, the third output terminal and the fourth output terminal to output a high level signal, so as to determine that the working mode of the driving circuit is a fifth working mode, and further determine that the threshold input voltage is a fifth threshold voltage, wherein the fifth threshold voltage is less than the fourth threshold voltage, at this time, the resistance value of the second unit is equal to the sum of the resistance values of the second resistor, the third resistor, the fourth resistor and the fifth resistor, and then the control unit controls the voltage providing unit to output the first input voltage matched with the fifth threshold voltage.

The driving circuit of the invention determines a plurality of different working modes according to different required voltages of the first integrated chip, and further determines different threshold input voltages of the first integrated chip. The threshold input voltage becomes larger as the required voltage becomes larger. In each working mode, the first integrated chip can work only when the first input voltage reaches the threshold input voltage at the moment, so that the voltage of the first control node coupled with the enabling port of the first integrated chip can reach the first enabling voltage, and the risk that the voltage level of the enabling port can still reach the first enabling voltage when the first input voltage is momentarily reduced, the first integrated chip still continues to work and the duty ratio is improved for normal work, and instantaneous large current is generated when the first input voltage is instantaneously restored to the original input voltage, so that the first integrated chip and electric elements of the first integrated chip are damaged is avoided.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

FIG. 1 is a schematic diagram of a prior art driver circuit;

FIG. 2 is a block diagram of a driving circuit according to an embodiment of the present invention;

FIG. 3 is a block diagram of another embodiment of a driving circuit according to the present invention;

fig. 4 is a schematic view of the protection unit of fig. 3.

Detailed Description

The following description of the embodiments refers to the accompanying drawings for illustrating the specific embodiments in which the invention may be practiced. The directional terms used in the present invention, such as "up", "down", "front", "back", "left", "right", "side", etc., refer to the directions of the attached drawings. Accordingly, the directional terms used are used for explanation and understanding of the present invention, and are not used for limiting the present invention.

In the following embodiments, the same portions are denoted by the same reference numerals in different drawings.

Referring to fig. 2, fig. 2 is a block diagram of a driving circuit according to an embodiment of the invention. The driving circuit 1000 of the present invention is used for driving the first integrated chip 2000, and the first integrated chip 2000 can be connected to at least one power consuming component 3000. The first integrated chip 2000 has an input port VIN and an enable port EN, the first integrated chip 2000 has a first enable voltage VE1, and when the voltage level of the enable port EN reaches the first enable voltage VE1, the first integrated chip 2000 operates. In practice, the first enable voltage VE1 may be a voltage level related to the characteristics of the first ic 2000 itself, and typically, the enable voltage of an ic may be a fixed value. In this embodiment, the first enable voltage VE1 of the first integrated chip 2000 is 1.21V.

As shown in fig. 2, the driving circuit 1000 includes a voltage providing unit 100 and a protection unit 200. The voltage providing unit 100 is coupled to the input port VIN of the first integrated chip 2000, and the voltage providing unit 100 is configured to provide a first input voltage. The protection unit 200 is coupled to the output terminal of the voltage providing unit 100, the protection unit 200 has a first control node Q1, the voltage at the first control node Q1 is defined as a first node voltage VQ1, and the first control node Q1 is coupled to the enable port EN of the first integrated chip 2000.

The driving circuit 1000 of the present invention can be applied to a whole system. In practical operation, the first ic 2000 has different required voltages according to different operation conditions of the whole system, and the driving circuit 1000 correspondingly has different operation modes. In this embodiment, the voltage providing unit 100 may be an adapter, and further, the voltage providing unit 100 may be a type-C adapter, the output voltage (i.e., the aforementioned first input voltage) of the adapter includes, for example, 5V, 9V, 12V, 15V, and 20V, and the specific output voltage of the adapter may be switched and adjusted according to an instruction of a power supply and power receiving control chip of the overall system. As shown in fig. 2, the driving circuit 1000 may further include a control unit 300, in practical operation, the control unit 300 is, for example, the above-mentioned power supply and power receiving control chip, and the control unit 300 is coupled to the voltage providing unit 100 to control the output voltage of the voltage providing unit 100. Specifically, the control unit 300 may have a first control terminal c1, and the first control terminal c1 is coupled to the voltage providing unit 100. In use, the control unit 300 sends a voltage command to the voltage providing unit 100 through the first control terminal c1 according to the current required voltage of the first integrated chip 2000, and the voltage providing unit 100 outputs a first input voltage matching the current requirement to the input port VIN of the first integrated chip 2000 according to the voltage command.

When the required voltage of the first integrated chip 2000 is the first required voltage according to the current operating condition, the driving circuit 1000 determines the first operating mode corresponding to the first required voltage, and further determines that the threshold input voltage of the first integrated chip 2000 is the first threshold voltage VD1, when the first input voltage reaches the first threshold voltage VD1, the first node voltage VQ1 reaches the first enable voltage VE1, and since the first control node Q1 is coupled to the enable port EN, the voltage level of the enable port EN also reaches the first enable voltage VE1, so that the first integrated chip 2000 operates; when the first input voltage is less than the first threshold voltage VD1, the first node voltage VQ1 is less than the first enable voltage VE1, so the voltage level of the enable port EN coupled to the first control node Q1 is also less than the first enable voltage VE1, and the first integrated chip 2000 does not operate.

In the present invention, when the first integrated chip 2000 determines that the required voltage is the first required voltage according to the current operation condition, the driving circuit 1000 determines the first operating mode and further determines the first threshold voltage VD1, and at this time, only when the first input voltage reaches the first threshold voltage VD1, the first node voltage VQ1 can reach the first enabling voltage VE1, and the enabling port EN can be enabled. The first threshold voltage VD1 may be a voltage level that is not directly related to the characteristics of the first ic 2000 itself, but rather is related to the first required voltage of the first ic 2000. In this embodiment, the first required voltage is 20V, and the first threshold voltage VD1 is 16V.

The following description will be made by taking a scenario in the background art as an example when the required voltage of the first integrated chip 2000 is the first required voltage. At this time, the driving circuit 1000 determines the first operation mode, and further determines the first threshold voltage VD1 of the first integrated chip 2000. In this embodiment, the first required voltage is 20V, the first threshold voltage VD1 is 16V, and the first enable voltage VE1 is 1.21V. Initially, the first input voltage outputted by the voltage providing unit 100 according to the current required voltage is 20V, and reaches the first threshold voltage VD1, the first node voltage VQ1 reaches the first enable voltage VE1, the enable port EN is enabled, and the first integrated chip 2000 operates. If the first input voltage output by the voltage providing unit 100 changes instantaneously due to poor contact or instantaneous power failure of some components (e.g., connectors) in the voltage providing unit 100, for example, drops from 20V to 7V and returns to 20V instantaneously, and when the first input voltage drops to 7V, it is smaller than the first threshold voltage VD1, then the first node voltage VQ1 is smaller than the first enable voltage VE1, so that the voltage level of the enable port EN is also smaller than the first enable voltage VE1, and the first integrated chip 2000 does not operate; when the first input voltage returns from 7V to 20V, the first input voltage reaches the first threshold voltage VD1, the enable port EN is enabled, and the first integrated chip 2000 resumes operation.

When the required voltage of the first integrated chip 2000 is the second required voltage according to the current operating condition, and the second required voltage is smaller than the first required voltage, the driving circuit 1000 determines the second operating mode corresponding to the second required voltage, and further determines that the threshold input voltage of the first integrated chip 2000 is the second threshold voltage VD2, and the second threshold voltage VD2 is smaller than the first threshold voltage VD 1. When the first input voltage reaches the second threshold voltage VD2, the first node voltage VQ1 reaches the first enable voltage VE1, and since the first control node Q1 is coupled to the enable port EN, the voltage level of the enable port EN also reaches the first enable voltage VE1, so that the first integrated chip 2000 operates; when the first input voltage is less than the second threshold voltage VD2, the first node voltage VQ1 is less than the first enable voltage VE1, so the voltage level of the enable port EN coupled to the first control node Q1 is also less than the first enable voltage VE1, and the first integrated chip 2000 does not operate.

In the present invention, when the first integrated chip 2000 determines that the required voltage is the second required voltage according to the current operation condition, the driving circuit 1000 determines the second operation mode and further determines the second gate-on voltage VD2, and at this time, only when the first input voltage reaches the second threshold voltage VD2, the first node voltage VQ1 can reach the first enable voltage VE1, and the enable port EN can be enabled. Similarly, the second threshold voltage VD2 may be a voltage level that is not directly related to the characteristics of the first ic 2000 itself, but rather is related to the second required voltage of the first ic 2000. In this embodiment, the second required voltage is, for example, 15V, and the second threshold voltage VD2 is 11V.

The case when the demand voltage of the first integrated chip 2000 is the second demand voltage is also explained by taking the scenario in the background art as an example. At this time, the driving circuit 1000 determines the second operation mode, and further determines the second threshold voltage VD2 of the first integrated chip 2000. In this embodiment, the second required voltage is 15V, the second threshold voltage VD2 is 11V, and the first enable voltage VE1 is still 1.21V. Initially, the first input voltage outputted by the voltage providing unit 100 according to the current demand voltage is 15V, and reaches the second threshold voltage VD2, and the first node voltage VQ1 reaches the first enable voltage VE1, the enable port EN is enabled, and the first integrated chip 2000 operates. If the first input voltage output by the voltage providing unit 100 changes instantaneously due to poor contact or instantaneous power failure of some components (e.g., connectors) in the voltage providing unit 100, for example, drops from 15V to 7V and returns to 15V instantaneously, and when the first input voltage drops to 7V, the first input voltage is smaller than the second threshold voltage VD2, the first node voltage VQ1 is smaller than the first enable voltage VE1, so that the voltage level of the enable port EN is also smaller than the first enable voltage VE1, and the first integrated chip 2000 does not operate; when the first input voltage returns from 7V to 15V, the first input voltage reaches the second threshold voltage VD2, the enable port EN is enabled, and the first integrated chip 2000 resumes operation.

In the present invention, the first ic 2000 has different required voltages according to different operation conditions, and the driving circuit 1000 determines a plurality of different operation modes and further determines different threshold input voltages of the first ic 2000. Generally, the threshold input voltage is increased along with the increase of the required voltage, that is, when the required voltage is larger, the corresponding threshold input voltage is also larger; when the required voltage is smaller, the corresponding threshold input voltage is also smaller. In each operating mode, only when the first input voltage reaches the threshold input voltage at this time, the voltage of the first control node Q1 coupled to the enable port EN of the first ic 2000 can reach the first enable voltage VE1, so that the first ic 2000 can operate, and the risk of damage to the first ic 2000 itself and the power consumption element 3000 due to the fact that the voltage level of the enable port EN can still reach the first enable voltage VE1 when the first input voltage is momentarily reduced is avoided, so that the first ic 2000 still continues to operate and the duty ratio is increased for normal operation, and when the first input voltage is momentarily restored to the original input voltage, a momentary large current is generated.

In practical applications, before the driving circuit 1000 of the present invention is used, threshold input voltages corresponding to different voltages required by the first ic 2000 can be set through experiments. Thus, when the driving circuit 1000 is used, after the current required voltage of the first integrated chip 2000 is determined, the threshold input voltage corresponding to the current required voltage can be quickly determined by the previous setting. The first required voltage of the first integrated chip 2000 is, for example, 20V. When the voltage received at the input port VIN of the first integrated chip 2000 is the first required voltage, the duty cycle of the first integrated chip 2000 reaches, for example, 30%. Then, the first input voltage received by the first integrated chip 2000 is instantaneously adjusted from 20V to the first voltage value and then returned to 20V, and the first voltage value may be selected from a plurality of experimental values in the experimental process. When the first input voltage drops from 20V to the first voltage value, assuming that the first integrated chip 2000 continues to operate and the duty ratio of the first integrated chip 2000 is increased to 35% compared to the previous duty ratio for normal operation, when the first input voltage is instantly restored to 20V from the first voltage value, the first integrated chip 2000 needs some reaction time to change the duty ratio from 35% to 30%, during which the first integrated chip 2000 and the electric component 3000 will bear the instantaneous large current, and when the instantaneous large current is determined to be the maximum safe current that the first integrated chip 2000 and the electric component 3000 can bear, the first voltage value selected in the current experiment can be determined to be the lowest safe voltage of the first integrated chip 2000, and the lowest safe voltage can be used as the threshold input voltage corresponding to the first required voltage. That is, when the required voltage of the first integrated chip 2000 is determined as the first required voltage, the lowest safe voltage acceptable for the first integrated chip 2000 can be determined according to the maximum safe current that the first integrated chip 2000 and the electric element 3000 thereof can bear, and the lowest safe voltage is set as the first threshold voltage VD 1. When the required voltage of the first integrated chip 2000 is other values, the corresponding threshold input voltage can be selected by the above method, which is not described herein.

Thus, even if the first input voltage outputted from the voltage supply unit 100 changes instantaneously during the operation of the driving circuit 1000, since different threshold input voltages are set for different desired voltages of the first integrated chip 2000, if the instantaneous variation range of the first input voltage is between the desired voltage and the corresponding threshold input voltage, for example, instantly falls from 20V to 17V and then returns to 20V, since 17V is larger than the corresponding threshold input voltage (e.g., 16V in this embodiment), the first integrated chip 2000 continues to operate, and even if the first input voltage is restored to the required voltage, a slightly larger current appears, however, it can be known from previous experiments that the current is still within the safe current range that the first ic 2000 and the electronic component 3000 can bear, and the first ic 2000 and the electronic component 3000 can work normally without being damaged. When the instantaneous variation range of the first input unit exceeds the range between the required voltage and the corresponding threshold input voltage, for example, the instantaneous variation range is from 20V to 7V and then returns to 20V, and since 7V is smaller than the corresponding threshold input voltage (for example, 16V in the present embodiment), the first ic no longer operates when the voltage is instantaneously reduced, so as to prevent the first ic 2000 and the electric element 3000 thereof from being damaged due to the instantaneous large current when the first input voltage returns to the required voltage. Since the instantaneous large current exceeds the safe current range that the first ic 2000 and the electric element 3000 thereof can bear, the first ic 2000 will be damaged if it works.

As shown in fig. 2, the protection unit 200 includes a first voltage dividing unit 210 and a second voltage dividing unit 220, the first voltage dividing unit 210 has a first terminal and a second terminal opposite to each other, the first terminal is coupled to the voltage providing unit 100 (specifically, the output terminal of the voltage providing unit 100), the second terminal is coupled to the first control node Q1, and the voltage across the first voltage dividing unit 210 is defined as a first divided voltage denoted as VF 1; the second voltage dividing unit 220 is connected in series with the first voltage dividing unit 210, and the second voltage dividing unit 220 has a third end and a fourth end opposite to each other, the third end is coupled to the second end of the first voltage dividing unit 210, and the fourth end is grounded. The voltage across the second voltage dividing unit 220 is defined as a second divided voltage, denoted as VF2, the first input voltage is denoted as V1, and the sum of the first divided voltage and the second divided voltage is equal to the first input voltage, i.e., V1 is VF1+ VF 2. In this embodiment, the first node voltage VQ1 is equal to the second divided voltage. In this way, the voltage level that the enable port EN of the first integrated chip 2000 can obtain is directly related to the first input voltage outputted by the voltage providing unit 100.

In this embodiment, the effective resistance of the first voltage divider unit 210 is the first unit resistance, denoted as R1, and the effective resistance of the second voltage divider unit 220 is the second unit resistance, denoted as R2, which satisfies the following conditions: VF2/V1 ═ R2/(R1+ R2). That is, the first node voltage VQ1 ═ V1 × R2/(R1+ R2). In practical operation, the effective resistance of the protection unit 200 can be defined as the total resistance, denoted as R0, and the above equation can be rewritten as the first node voltage VQ1 being V1R 2/R0. The magnitude of the first node voltage VQ1 is related to the magnitude of the first input voltage and the ratio of the second cell resistance to the total resistance of the protection cell 200. It can be determined that the ratio of the second cell resistance to the total resistance of the protection cell 200 is the first ratio, and the enable port EN of the first ic 2000 is coupled to the first control node Q1, and the voltage level of the enable port EN of the first ic 2000 depends on the first input voltage and the first ratio.

In the present invention, when the required voltages of the first integrated chip 2000 are different, the driving circuit 1000 determines different operation modes, and the ratio of the second divided voltage to the first input voltage may be different. Specifically, the second cell resistance value may be different when the required voltage of the first integrated chip 2000 is different. For example, when the required voltage of the first integrated chip 2000 is the first required voltage, the first required voltage is, for example, 20V, the second unit resistance may be 8.18k Ω, and the first unit resistance may be 100k Ω, so that the ratio of the second divided voltage to the first input voltage is equal to the ratio of the second unit resistance to the total resistance of the protection unit 200, that is, 8.18/(8.18+10) ═ 0.0756. When the required voltage of the first integrated chip 2000 is the second required voltage, the second required voltage is, for example, 15V, the first unit resistance may be 100k Ω, and the second unit resistance is changed to 12.36k Ω, so that the ratio of the second divided voltage to the first input voltage is equal to the ratio of the second unit resistance to the total resistance of the protection unit 100, that is, 12.36/(100+12.36) ═ 0.11. Generally, the ratio of the second divided voltage to the first input voltage increases as the required voltage of the first integrated chip 2000 becomes smaller, therefore, when the required voltage of the first integrated chip 2000 is larger, the first input voltage output by the voltage supply unit 100 is larger, since the ratio of the second divided voltage (i.e., the first node voltage VQ1) to the first input voltage is smaller, the voltage level of the enable port EN can reach the first enable voltage VE1 only when the first input voltage reaches a larger threshold voltage, when the required voltage of the first integrated chip 2000 is smaller, the first input voltage output by the voltage providing unit 100 is smaller, since the ratio of the second divided voltage (i.e., the first node voltage VQ1) to the first input voltage is larger, the voltage level of the enable port EN can reach the first enable voltage VE1 when the first input voltage is required to reach the smaller threshold voltage. In other words, the threshold input voltage of the first integrated chip 2000 of the present invention becomes larger as the required voltage thereof becomes larger.

In practice, the first voltage dividing unit 210 may include a first number of resistors, where the first number is ≧ 1. The first number of resistors may be connected, for example, in series. The second voltage divider unit 220 may include a second number of resistors, which is ≧ 2, which may also be connected, for example, in series.

As shown in fig. 2, in the present embodiment, the first voltage dividing unit 210 may include 1 resistor, which is defined as a first resistor 211, and the first resistor 211 has a first resistance value, denoted as R1, which is equal to the first unit resistance value, i.e., R1 — R1. In this embodiment, the first resistance of the first resistor 211 is 100k Ω. The second voltage divider unit 220 may include 2 resistors connected in series and respectively defined as a second resistor 221 and a third resistor 222, wherein the second resistor 221 has a second resistance value r2, and the third resistor 222 has a third resistance value r 3. In this embodiment, the second resistance of the second resistor 221 is 8.18k Ω, and the third resistance of the third resistor 222 is 4.18k Ω.

When the required voltage of the first integrated chip 2000 is the first required voltage (20V in this embodiment), the driving circuit 1000 determines the first operating mode, and at this time, the second unit resistance value is equal to the second resistance value, that is, R2 is R2, and according to that the ratio of the second divided voltage to the first input voltage is equal to the ratio of the second unit resistance value to the total resistance value of the protection unit 200, the following steps are obtained: VF2/V1 ═ R2/(R1+ R2) ═ R2/(R1+ R2). VF2/V1 is thus calculated to be 0.0756, so that when the first input voltage reaches the first threshold voltage VD1 (16V in this embodiment), the first node voltage VQ1 is 16 × 0.0756V to be 1.21V, and reaches the first enable voltage VE1, enabling the enable port EN.

When the required voltage of the first integrated chip 2000 is the second required voltage (15V in this embodiment), the driving circuit 1000 determines the second operating mode, and obtains the following result according to that the ratio of the second divided voltage to the first input voltage is equal to the ratio of the second unit resistance value to the total resistance value of the protection unit 200:

VF2/V1 ═ R2/(R1+ R2) ═ R2+ R3)/(R1+ R2+ R3. It is thus calculated that VF2/V1 is 0.11, so that when the first input voltage reaches the second threshold voltage VD2 (11V in the present embodiment), the first node voltage VQ1 is 11 × 0.11V is 1.21V, and the first enable voltage VE1 is reached, enabling the enable port EN.

The method for obtaining the different second cell resistance values in different operation modes is described below. As shown in fig. 2, the protection unit 200 further has a second control node Q2, the control unit 300 further has a first output end out1, the first output end out1 is used for outputting a first level signal, the first output end out1 is coupled to the second control node Q2, one end of the second resistor 221 is the third end, the other end of the second resistor 221 is coupled to the second control node Q2, one end of the third resistor 222 is coupled to the second control node Q2, and the other end of the third resistor 222 is grounded. When the required voltage of the first integrated chip 2000 is the first required voltage, the driving circuit 1000 determines the first operating mode, the control unit 300 controls the first output terminal out1 to output the first level signal, and at this time, the first level signal is a low level signal, and the second control node Q2 is pulled low, so that one end of the second resistor 221 is coupled to the first control node, and the other end of the second resistor is regarded as ground, so that the effective resistor included in the second voltage dividing unit 220 is only the second resistor 221, and the second unit resistance value is equal to the second resistance value of the second resistor 221, that is, R2 is R2; when the required voltage of the first integrated chip 2000 is the second required voltage, the driving circuit 1000 determines the second operating mode, the control unit 300 controls the first output segment out1 to output the first level signal, at this time, the first level signal is a high level signal, and the second control node Q2 maintains a normal high level, so that the effective resistors included in the second voltage dividing unit 220 are the second resistor 221 and the third resistor 222 connected in series, and thus the second unit resistance value is equal to the sum of the second resistance value of the second resistor 221 and the third resistance value of the third resistor 222, i.e., R2 is equal to (R2+ R3). In this way, in different operation modes, the driving circuit 1000 outputs different level signals to control the voltage level of the second control node Q2, so as to change the effective resistance included in the second voltage dividing unit 220, thereby obtaining different second unit resistance values.

In this embodiment, the first voltage dividing unit 210 only includes the first resistor 211, so the first unit resistance is a fixed value, and the second unit resistance of the second voltage dividing unit 220 is a variable value in different operating modes, so that the ratio of the second unit resistance to the total resistance of the protection unit 200 is different in different operating modes, so as to realize that the larger the required voltage of the first integrated chip 2000 is, the larger the threshold input voltage thereof is. In practical operation, the first unit resistance of the first voltage dividing unit 210 and the second unit resistance of the second voltage dividing unit 220 may be set to be variable values, or the first unit resistance of the first voltage dividing unit 210 is a variable value while the second unit resistance of the second voltage dividing unit 220 is a fixed value. The larger the required voltage of the first integrated chip 2000 is, the larger the threshold input voltage is, and when the first input voltage reaches the corresponding threshold input voltage, the voltage level of the enable port EN reaches the first enable voltage VE 1.

In practical operation, in order to further improve the operation stability and safety of the driving circuit 1000 and the first integrated chip 2000, as shown in fig. 2, the control unit 300 further has a first control terminal c1, and the first control terminal c1 is coupled to the voltage providing unit 100. When determining the current required voltage of the first integrated chip 2000 according to the current operating condition, the driving circuit 1000 first provides a first level signal to the protection unit 200 through the first output terminal out1 of the control unit 300 according to the current required voltage to determine the corresponding current operating mode. Since the threshold input voltages of the corresponding first integrated chips 2000 in different operating modes are different, the threshold input voltage corresponding to the current operating mode can be determined after the current operating mode is determined. Then, the driving circuit 1000 provides the first voltage signal to the voltage providing unit 100 through the first control terminal c1 of the control unit 300 according to the current demand voltage, and the voltage providing unit 100 outputs the first input voltage matching the current demand voltage according to the first voltage signal. In this way, when the input port VIN of the first integrated chip 2000 receives the first input voltage matching the current demand voltage output from the voltage providing unit 100, it is ensured that the current threshold input voltage is adjusted to a state matching the current demand voltage, so that the driving circuit 1000 operates more stably.

In practical operation, in order to further improve the operation stability and safety of the driving circuit 1000 and the first ic 2000, as shown in fig. 2, the control unit 300 further has a second control terminal c2, and the second control terminal c2 is coupled to the enable port EN of the first ic 2000. In this embodiment, the second control terminal c2 is coupled to the first control node Q1, and the first control node Q1 is coupled to the enable port EN, so that the second control terminal c2 is coupled to the enable port EN. After determining the current required voltage of the first integrated chip 2000 according to the current operating condition, the driving circuit 1000 first provides a first level signal to the protection unit 200 through the first output terminal out1 of the control unit 300 according to the current required voltage to determine the corresponding current operating mode, so as to determine the threshold input voltage corresponding to the current operating mode. Then, the driving circuit 1000 outputs a high signal through the second control terminal c2 of the control unit 300 to open the enable port EN, so that the first integrated chip 2000 operates when the first input voltage reaches the threshold input voltage corresponding to the current operating mode. In this embodiment, the second control terminal c2 is similar to a switch of the enable port EN, and when the second control terminal c2 outputs a high level signal, the enable port EN is opened to receive the first node voltage VQ1 of the first control node Q1, and is enabled to enable the first integrated chip 2000 to operate when the first node voltage VQ1 reaches the first enable voltage VE 1; when the second control terminal c2 outputs a low level signal, the enable port EN is turned off, and the first integrated chip 2000 does not operate no matter whether the first input voltage reaches the threshold input voltage. Thus, when the input port VIN of the first integrated chip 2000 receives the first input voltage matched with the current demand voltage output from the voltage providing unit 100, it is ensured that the driving circuit 1000 has determined the current operating mode according to the current demand voltage and has set the corresponding threshold input voltage, and the current threshold input voltage has been adjusted to a state matched with the current demand voltage, so that the driving circuit 1000 operates more stably.

In this embodiment, the first voltage dividing unit 210 includes 1 resistor, the second voltage dividing unit 220 includes 2 resistors, the protection unit 200 includes two control nodes, and the second voltage dividing unit 220 has two second unit resistances, so that the driving circuit 1000 has two working modes for the first integrated chip 2000 to switch between two different voltages. In practical operation, the first number and the second number may be other values, so that the protection unit 200 has a plurality of (more than two) control nodes, and the second voltage dividing unit 220 has a plurality of (more than two) second unit resistances, so that the driving circuit 1000 has a plurality of (more than two) working modes for the first ic 2000 to switch to use when having a plurality of different required voltages.

Referring to fig. 3 and 4, fig. 3 is a block diagram illustrating a driving circuit according to another embodiment of the present invention; fig. 4 is a schematic view of the protection unit of fig. 3. In this embodiment, the first voltage dividing unit 210 still includes only 1 resistor, which is defined as the first resistor 211, and the first resistor 211 has a first resistance value, denoted as R1, which is equal to the first unit resistance value, i.e., R1 is R1. Unlike the embodiment shown in fig. 2, in the present embodiment, the second voltage dividing unit 220' has 5 resistors connected in series, which are respectively defined as a second resistor 221, a third resistor 222, a fourth resistor 223, a fifth resistor 224 and a sixth resistor 225, the protection unit 200 correspondingly has a second control node Q2, a third control node Q3, a fourth control node Q4 and a fifth control node Q5, one end of the second resistor 221 is the third terminal of the second voltage dividing unit 220, the other end of the second resistor 221 is coupled to the second control node Q2, one end of the third resistor 222 is coupled to the second control node Q2, the other end of the third resistor 222 is coupled to the third control node Q3, one end of the fourth resistor 223 is coupled to the third control node Q3, the other end of the fourth resistor 223 is coupled to the fourth control node Q4, one end of the fifth resistor 224 is coupled to the fourth control node Q4, and the other end of the fifth resistor 224 is coupled to the fifth control node Q5, one end of the sixth resistor 225 is coupled to the fifth control node Q5, and the other end of the sixth resistor 225 is grounded. The driving circuit 1000 ' further includes a control unit 300 ', the control unit 300 ' has a first output end 1, a second output end out2, a third output end out3 and a fourth output end out4, the first output end out1 is coupled to the second control node Q2, the second output end out2 is coupled to the third control node Q3, the third output end out3 is coupled to the fourth control node Q4, and the fourth output end out4 is coupled to the fifth control node Q5.

When the required voltage of the first integrated chip 2000 is the first required voltage according to the current operating condition, the driving circuit 1000 'first sends a first level signal through the control unit 300' according to the first required voltage to control the first output terminal out1 to output a low level signal, and the second output terminal out2, the third output terminal out3 and the fourth output terminal out4 to output a high level signal, so that the first integrated chip 300 'first sends the first level signal to determine that the operating mode of the driving circuit 1000' is the first operating mode, and determines that the threshold input voltage of the first integrated chip 2000 is the first threshold voltage VD1 according to the first operating mode. In this embodiment, the first required voltage is 20V. Since the first output terminal out1 outputs a low level signal and the other output terminals output high level signals, the second control node Q2 coupled to the first output terminal out1 is pulled low, and the other control nodes maintain a normal high voltage level, so that one end of the second resistor 221 is coupled to the first control node Q1, and the other end is regarded as ground, so that the effective resistor included in the second voltage dividing unit 220' is only the second resistor 221, and the second unit resistance is equal to the second resistor 221 resistance. In this embodiment, the resistance of the first resistor 211 is, for example, 100k Ω, the resistance of the second resistor 222 is, for example, 8.18k Ω, and the first enable voltage VE1 is 1.21V, and when the first input voltage reaches the first threshold voltage VD1, the first node voltage VQ1 reaches the first enable voltage VE1, so that 1.21 ═ V1 × 8.18/(100+8.18) is obtained, so that in the first operating mode, when the first node voltage VQ1 reaches the first enable voltage VE1, the first input voltage is 16V, and at this time, the first input voltage reaches the first threshold voltage VD1, that is, the first threshold voltage VD1 of the first integrated chip 2000 is 16V. Then, the driving circuit 1000 'controls the first control terminal c1 of the control unit 300' to send a first voltage signal to the voltage providing unit 100 according to the first required voltage, and the voltage providing unit 100 outputs a first input voltage matched with the first required voltage according to the first voltage signal. In this embodiment, the first input voltage at this time may be equal to the first required voltage, i.e. 20V.

When the required voltage of the first integrated chip 2000 is the second required voltage according to the current operating condition, the driving circuit 1000 'first sends a second level signal through the control unit 300' according to the second required voltage to control the first output terminal out1, the third output terminal out3 and the fourth output terminal out4 to output a high level signal, and the second output terminal out2 outputs a low level signal, so that the control unit 300 'first sends the second level signal to determine that the operating mode of the driving circuit 1000' is the second operating mode, and determines that the threshold input voltage of the first integrated chip 2000 is the second threshold voltage VD2 according to the second operating mode. In this embodiment, the second required voltage is 15V. Since the third control node Q3 coupled to the second input terminal out2 is pulled low and the remaining control nodes are maintained at a normal high voltage level, one end of the third resistor 222 is coupled to the second control node Q2, and the other end is regarded as ground, so that the effective resistors included in the second voltage dividing unit 220' are the second resistor 221 and the third resistor 222, and the second unit resistance is equal to the sum of the resistances of the second resistor 221 and the third resistor 222. In this embodiment, the resistance of the first resistor 211 is 100k Ω, the resistance of the second resistor 221 is 8.18k Ω, the resistance of the third resistor 222 is 4.18k Ω, the first enable voltage VE1 is 1.21V, and when the first input voltage reaches the second threshold voltage VD2, the first node voltage VQ1 reaches the first enable voltage VE1, then:

1.21＝V1*(8.18+4.18)/(100+8.18+4.18)；

therefore, in the second operation mode, when the first node voltage VQ1 reaches the first enable voltage VE1, the first input voltage is 11V, and the first input voltage reaches the second threshold voltage VD2, that is, the second threshold voltage VD2 of the first integrated chip 2000 is determined to be 11V. Then, the driving circuit 1000 'controls the first control terminal c1 of the control unit 300' to send a second voltage signal to the voltage providing unit 100 according to the second required voltage, and the voltage providing unit 100 outputs a first input voltage matched with the second required voltage according to the second voltage signal. In this embodiment, the first input voltage may be equal to the second required voltage, i.e. 15V.

When the required voltage of the first integrated chip 2000 is the third required voltage according to the current operation condition, the driving circuit 1000 'first sends a third level signal through the control unit 300' according to the third required voltage to control the first output end out1, the second output end out2 and the fourth output end out4 to output a high level signal, and the third output end out3 outputs a low level signal, so that the control unit 300 'first sends the third level signal to determine that the operation mode of the driving circuit 1000' is the third operation mode, and determines that the threshold input voltage of the first integrated chip 2000 is the third threshold voltage VD3 according to the third operation mode, and the third threshold voltage VD3 is smaller than the second threshold voltage VD 2. In this embodiment, the third required voltage is 12V. Since the fourth control node Q4 coupled to the third input terminal out3 is pulled low and the remaining control nodes are maintained at a normal high voltage level, one end of the fourth resistor 223 is coupled to the third control node Q3, and the other end is regarded as ground, so that the effective resistors included in the second voltage dividing unit 220' are the second resistor 221, the third resistor 222 and the fourth resistor 223, and the second unit resistance is equal to the sum of the resistances of the second resistor 221, the third resistor 222 and the fourth resistor 223. In this embodiment, the resistance of the first resistor 211 is 100k Ω, the resistance of the second resistor 221 is 8.18k Ω, the resistance of the third resistor 222 is 4.18k Ω, the resistance of the fourth resistor 223 is 5.46k Ω, and the first enable voltage VE1 is 1.21V, and when the first input voltage reaches the third threshold voltage VD3, the first node voltage VQ1 reaches the first enable voltage VE1, then: 1.21 ═ V1 (8.18+4.18+5.46)/(100+8.18+4.18+ 5.46). Therefore, in the third operating mode, when the first node voltage VQ1 reaches the first enable voltage VE1, the first input voltage is 8V, and at this time, the first input voltage reaches the third threshold voltage VD3, that is, it is determined that the third threshold voltage VD3 of the first integrated chip 2000 is 8V. Then, the driving circuit 1000 'controls the first control terminal c1 of the control unit 300' to send a third voltage signal to the voltage providing unit 100 according to the third required voltage, and the voltage providing unit 100 outputs a first input voltage matched with the third required voltage according to the third voltage signal. In this embodiment, the first input voltage at this time may be equal to the third required voltage, i.e. 12V.

When the required voltage of the first integrated chip 2000 is the fourth required voltage according to the current operation condition, the driving circuit 1000 'first sends a fourth level signal through the control unit 300' according to the fourth required voltage to control the first output end out1, the second output end out2 and the third output end out3 to output a high level signal, and the fourth output end out4 outputs a low level signal, so that the control unit 300 'first sends the fourth level signal to determine that the operation mode of the driving circuit 1000' is the fourth operation mode, and determines that the threshold input voltage of the first integrated chip 2000 is the fourth threshold voltage VD4 according to the fourth operation mode, and the fourth threshold voltage VD4 is smaller than the third threshold voltage VD 3. In this embodiment, the fourth required voltage is 9V. Since the fifth control node Q5 coupled to the fourth input terminal out3 is pulled low and the remaining control nodes are maintained at a normal high voltage level, one end of the fifth resistor 224 is coupled to the fourth control node Q4, and the other end is regarded as ground, so that the effective resistors included in the second voltage dividing unit 220' are the second resistor 221, the third resistor 222, the fourth resistor 223 and the fifth resistor 224, and the second unit resistance is equal to the sum of the second resistor 221, the third resistor 222, the fourth resistor 223 and the fifth resistor 224. In this embodiment, the resistance of the first resistor 211 is 100k Ω, the resistance of the second resistor 221 is 8.18k Ω, the resistance of the third resistor 222 is 4.18k Ω, the resistance of the fourth resistor 223 is 5.46k Ω, the resistance of the fifth resistor 224 is 14.11k Ω, and the first enable voltage VE1 is 1.21V, and when the first input reaches the fourth threshold voltage VD4, the first node voltage VQ1 reaches the first enable voltage VE1, so that: 1.21 ═ V1 (8.18+4.18+5.46+14.11)/(100+8.18+4.18+5.46+ 14.11). In the fourth operation mode, when the first node voltage VQ1 reaches the first enable voltage VE1, the first input voltage is 5V, and the first input voltage reaches the third threshold voltage VD3, that is, the first threshold voltage VD2 of the first integrated chip 2000 is determined to be 5V. Then, the driving circuit 1000 'controls the first control terminal c1 of the control unit 300' to send a fourth voltage signal to the voltage providing unit 100 according to the fourth required voltage, and the voltage providing unit 100 outputs a first input voltage matched with the fourth required voltage according to the fourth voltage signal, in this embodiment, the first input voltage may be equal to the fourth required voltage, that is, 9V.

When the required voltage of the first integrated chip 2000 is the fifth required voltage according to the current operating condition, the driving circuit 1000 'first sends a fifth level signal through the control unit 300' according to the fifth required voltage to control the first output end out1, the second output end out2, the third output end out3 and the fourth output end out4 to output a high level signal, so that the control unit 300 'first sends the fifth level signal to determine that the operating mode of the driving circuit 1000' is the fifth operating mode, and determines that the threshold input voltage of the first integrated chip 2000 is the fifth threshold voltage VD5 according to the fifth operating mode, and the fifth threshold voltage VD5 is smaller than the fourth threshold voltage VD 4. In this embodiment, the fifth required voltage is 5V. Since all the control nodes are maintained at the normal high voltage level, one end of the sixth resistor 225 is coupled to the fifth control node Q5, and the other end is grounded, so that the effective resistors included in the second voltage dividing unit 220' are the second resistor 221, the third resistor 222, the fourth resistor 223, the fifth resistor 224, and the sixth resistor 225, and therefore the second unit resistance is equal to the sum of the resistances of the second resistor 221, the third resistor 222, the fourth resistor 223, the fifth resistor 224, and the sixth resistor 225. In this embodiment, the resistance of the first resistor 211 is 100k Ω, the resistance of the second resistor 221 is 8.18k Ω, the resistance of the third resistor 222 is 4.18k Ω, the resistance of the fourth resistor 223 is 5.46k Ω, the resistance of the fifth resistor 224 is 14.11k Ω, the resistance of the sixth resistor 225 is 2.74k Ω, the first enabling voltage VE1 is 1.21V, and when the first input voltage reaches the fifth threshold voltage VD5, the first node voltage VQ1 reaches the first enabling voltage VE1, so that: 1.21 ═ V1, (8.18+4.18+5.46+14.11+2.74)/(100+8.18+4.18+5.46+14.11+ 2.74). In the fifth operating mode, when the first node voltage VQ1 reaches the first enable voltage VE1, the first input voltage is 4.7V, and the first input voltage reaches the fifth threshold voltage VD5, that is, the fifth threshold voltage VD5 of the first integrated chip 2000 is determined to be 4.7V. Then, the driving circuit 1000 'controls the first control terminal c1 of the control unit 300' to send a fifth voltage signal to the voltage providing unit 100 according to the fifth required voltage, and the voltage providing unit 100 outputs a first input voltage matched with the fifth required voltage according to the fifth voltage signal, in this embodiment, the first input voltage may be equal to the fifth required voltage, that is, 5V.

In this way, in different operating modes, the driving circuit 1000 controls the potentials of the control nodes by outputting different level signals, so as to change the effective resistance included in the second voltage dividing unit 220 ', thereby obtaining different second unit resistance values, and making the ratio of the second divided voltage at the two ends of the second voltage dividing unit 220' to the first input voltage different.

The above detailed description of the preferred embodiments is intended to more clearly illustrate the features and spirit of the present invention, and is not intended to limit the scope of the present invention by the preferred embodiments disclosed above. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. The scope of the claims to be accorded the invention is therefore to be accorded the broadest interpretation so as to encompass all such modifications and equivalent arrangements as is known in the art.

Claims

1. A driving circuit for driving a first IC chip having an input port and an enable port, the first IC chip having a first enable voltage, the driving circuit comprising:

when the required voltage of the first integrated chip is a second required voltage, the second required voltage is smaller than the first required voltage, the driving circuit determines a second working mode corresponding to the second required voltage, and further determines that the threshold input voltage of the first integrated chip is a second threshold voltage, the second threshold voltage is smaller than the first threshold voltage, when the first input voltage reaches the second threshold voltage, the first node voltage reaches the first enabling voltage, and the first integrated chip works; and

when the driving circuit is in the first working mode, if the first input voltage is smaller than the first threshold voltage, the first node voltage is smaller than the first enabling voltage, and the first integrated chip does not work; when the driving circuit is in the second working mode, if the first input voltage is smaller than the second threshold voltage, the first node voltage is smaller than the first enabling voltage, and the first integrated chip does not work.

2. The drive circuit according to claim 1, wherein: the protection unit includes:

the second voltage division unit is connected with the first voltage division unit in series, the second voltage division unit is provided with a third end and a fourth end which are opposite, the third end is coupled with the second end, the fourth end is grounded, the voltages at the two ends of the second voltage division unit are second divided voltages, the sum of the first divided voltage and the second divided voltage is equal to the first input voltage, the first node voltage is equal to the second divided voltage, and when the required voltages of the first integrated chip are different, the ratio of the second divided voltage to the first input voltage is different.

3. The drive circuit according to claim 2, wherein: the effective resistance value of the first voltage dividing unit is a first unit resistance value, which is denoted as R1, the effective resistance value of the second voltage dividing unit is a second unit resistance value, which is denoted as R2, the first input voltage is denoted as V1, and the second voltage dividing unit is denoted as VF2, and then: VF2/V1 ═ R2/(R1+ R2), and when the required voltages of the first ic chip are different, the resistances of the second cells are different.

4. The drive circuit according to claim 3, wherein: this first partial pressure unit contains first quantity resistance, and this first quantity is ≧ 1, and this second partial pressure unit contains second quantity resistance, and this second quantity is ≧ 2.

5. The drive circuit according to claim 4, wherein: the first voltage division unit comprises 1 resistor defined as a first resistor, the resistance value of the first resistor is a first resistance value, the resistance value of the first unit is equal to the first resistance value, the second voltage division unit comprises 2 resistors connected in series and respectively defined as a second resistor and a third resistor, the resistance value of the second resistor is a second resistance value, the resistance value of the third resistor is a third resistance value, and when the driving circuit is in the first working mode, the second unit resistance value is equal to the second resistance value; when the driving circuit is in the second working mode, the resistance value of the second unit is equal to the sum of the second resistance value and the third resistance value.

6. The drive circuit according to claim 5, wherein: the protection unit further has a second control node, the driving circuit further includes a control unit, the control unit has a first output end, the first output end is used for outputting a first level signal, the first output end is coupled to the second control node, one end of the second resistor is the third end, the other end of the second resistor is coupled to the second control node, one end of the third resistor is coupled to the second control node, and the other end of the third resistor is the fourth end, wherein when the driving circuit is in the first working mode, the first level signal is a low level signal, the effective resistor included in the second voltage division unit is the second resistor, and the resistance value of the second unit is equal to the second resistance value; when the driving circuit is in the second working mode, the first level signal is a high level signal, the effective resistors included in the second voltage division unit are the second resistor and the third resistor, and the resistance value of the second unit is equal to the sum of the second resistance value and the third resistance value.

7. The drive circuit according to claim 6, wherein: the control unit is also provided with a first control end which is coupled with the voltage providing unit, when in use, the control unit firstly provides a first level signal to the protection unit through the first output end according to the required voltage of the first integrated chip so as to determine the working mode of the driving circuit and the threshold input voltage of the first integrated chip, then the control unit provides a voltage signal to the voltage providing unit through the first control end according to the required voltage, and the voltage providing unit outputs the matched first input voltage according to the voltage signal.

8. The drive circuit according to claim 7, wherein: the control unit is also provided with a second control end which is coupled with the enabling port of the first integrated chip, when in use, the control unit firstly provides a first level signal to the protection unit through the first output end according to the required voltage of the first integrated chip so as to determine the working mode of the driving circuit and the threshold input voltage of the first integrated chip, and then the first control end outputs a high level signal.

9. The drive circuit according to claim 4, wherein: the first voltage-dividing unit comprises 1 resistor defined as a first resistor, the resistance of the first resistor is the resistance of the first unit, the second voltage-dividing unit comprises 5 resistors connected in series and respectively defined as a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor, the protection unit further comprises a second control node, a third control node, a fourth control node and a fifth control node, one end of the second resistor is the third end, the other end of the second resistor is coupled with the second control node, one end of the third resistor is coupled with the second control node, the other end of the third resistor is coupled with the third control node, one end of the fourth resistor is coupled with the third control node, the other end of the fourth resistor is coupled with the fourth control node, one end of the fifth resistor is coupled with the fourth control node, and the other end of the fifth resistor is coupled with the fifth control node, one end of the sixth resistor is coupled to the fifth control node, the other end of the sixth resistor is grounded, the driving circuit further comprises a control unit having a first control end, a first output end, a second output end, a third output end and a fourth output end, the first control end is coupled to the voltage providing unit, the first output end is coupled to the second control node, the second output end is coupled to the third control node, the third output end is coupled to the fourth control node, the fourth output end is coupled to the fifth control node, wherein,

when the required voltage of the first integrated chip is a fifth required voltage, and the fifth required voltage is less than the fifth required voltage, the driving circuit sends a fifth level signal corresponding to the fifth required voltage through the control unit to control the first output terminal, the second output terminal, the third output terminal, and the fourth output terminal to output a high level signal, so as to determine that the working mode of the driving circuit is a fifth working mode, and further determine that the threshold input voltage is a fifth threshold voltage, and the fifth threshold voltage is less than the fourth threshold voltage, at this time, the second unit resistance value has a sum of resistance values equal to the second resistor, the third resistor, the fourth resistor, and the fifth resistor, and then the control unit controls the voltage providing unit to output the first input voltage matching the fifth threshold voltage.