High-voltage-difference, high-efficiency, wide-current and low-quiescent-current circuit

Abstract

The utility model discloses a high-voltage-difference, high-efficiency, wide-current and low-quiescent-current circuit, and relates to the technical field of circuit control, the circuit is externally connected with an input voltage and comprises a low-power-consumption voltage stabilizing circuit, a switch voltage stabilizing circuit, a change-over switch circuit and a comparison circuit, the input voltage supplies power to the VIN end of the low-power-consumption voltage stabilizing circuit and the VIN end of the switch voltage stabilizing circuit, and the comparison circuit supplies power to the VIN end of the change-over switch circuit. The input end of the comparison circuit is connected with a reference voltage and a thermistor, the output end of the comparison circuit is connected with the enabling end of the switch voltage stabilizing circuit, the output end of the switch voltage stabilizing circuit and the output end of the low-power-consumption voltage stabilizing circuit are connected with a change-over switch circuit, and the output end of the change-over switch circuit serves as the total output end of the circuit. The working mode of the LDO (low dropout regulator) can be controlled through hardware lap joint and temperature induction, and the low dropout regulator has the advantages of being high in safety, easy to operate and high in reliability.

Description

Technical Field

[0001] The invention relates to the technical field of circuit control, in particular to a high voltage difference, high efficiency, wide current and low quiescent current circuit. Background Art

[0002] In some battery management system (BMS) application circuits, it is often necessary to obtain voltage directly from the high-voltage bus to continuously power the MCU microprocessor and peripheral circuits.

[0003] The current of a microprocessor can often vary from several UA to tens of mA. For example, the MCU is in sleep mode at 10UA, but reaches 50MA when working, and the voltage difference is 60V.

[0004] At this time, the power consumption of LDO reaches 60*0.05=3w. Such high power consumption will cause a lot of heat and the efficiency is very low, but it will reach the UA level in deep sleep. Summary of the invention

[0005] The present invention proposes a high voltage difference, high efficiency, wide current and low quiescent current circuit, which can control the working mode of LDO (low voltage difference linear regulator) through hardware overlap and temperature sensing, and has the characteristics of high safety, easy operation and strong reliability.

[0006] The technical solution of the present invention is as follows:

[0007] A high-voltage difference, high-efficiency, wide-current, low-quiescent-current circuit, the circuit is externally connected to an input voltage, comprises a low-power voltage regulator circuit, a switching voltage regulator circuit, a switching switch circuit and a comparison circuit, the VIN terminals of the low-power voltage regulator circuit and the switching voltage regulator circuit are powered by the input voltage, the input of the comparison circuit is connected to a reference voltage and a thermistor, the output terminal of the comparison circuit is connected to an enable terminal of the switching voltage regulator circuit, the output terminals of the switching voltage regulator circuit and the low-power voltage regulator circuit are connected to a switching switch circuit, and the output terminal of the switching switch circuit serves as the total output terminal of the circuit.

[0008] As a further optimization of this solution, the low-power voltage stabilization circuit includes a low-power voltage regulator, a VIN pin of the low-power voltage regulator is connected to an input voltage, and capacitors are connected in series between the input and output of the low-power voltage regulator and the power ground.

[0009] As a further optimization of this solution, the switching regulator circuit includes a switching regulator, the VIN pin of the switching regulator is connected to the input voltage, the enable end of the switching regulator is connected to the output of the comparison circuit, the SW pin of the switching regulator serves as the output of the switching regulator circuit, and the BST pin of the switching regulator is connected to the SW pin through a capacitor C3.

[0010] As a further optimization of this solution, the SW pin of the switching regulator is connected to an inductor L1, a capacitor and a resistor connected in parallel are connected between the other end of the inductor L1 and the power ground, and a Zener diode D1 is connected between the SW pin of the switching regulator and the power ground.

[0011] As a further optimization of this solution, the comparison circuit includes a comparator, a thermistor NTC1 and a resistor R4 are connected in series between the in-phase terminal of the comparator and the reference voltage, and the output terminal of the comparator is connected to the enable terminal of the switching voltage regulator circuit.

[0012] As a further optimization of this solution, the switching switch circuit includes multiple switching tubes, and the controlled end of the switching switch circuit is connected to the output end of the comparison circuit. When the switching switch circuit turns on the low-power voltage regulator circuit, the switching voltage regulator circuit is disconnected, and the low-power voltage regulator circuit is used as the total output; when the switching switch circuit short-circuits the low-power voltage regulator circuit, the switching voltage regulator circuit is turned on, and the switching voltage regulator circuit is used as the total output.

[0013] As a further optimization of this solution, the switching circuit includes MOSFETs Q1-Q3, the MOSFETs Q1 and Q2 are pmos, the MOSFET Q3 is nmos, the gates of the MOSFETs Q1 and Q3 are connected to the output of the comparison circuit, the source of the MOSFET Q1 is connected to the output of the low-power voltage regulator circuit, the source of the MOSFET Q2 is connected to the output of the switching voltage regulator circuit, the drains of the MOSFET Q1 and the MOSFET Q2 are connected in parallel as a total output, the gate of the MOSFET Q2 is connected to the drain of the MOSFET Q3, and the source of the MOSFET Q3 is grounded.

[0014] The working principle and beneficial effects of the present invention are:

[0015] Because an increase in current or a larger voltage difference will increase the LDO power consumption and eventually cause the temperature to rise, this design directly controls the system to enter the LDO or DC / DC working mode by detecting temperature changes.

[0016] The entire power supply system is composed of ultra-low static power consumption LDO, DC / DC converter, comparator, MOS tube and other devices. LDO provides 3.3V power supply voltage to power the ultra-low power consumption comparator.

[0017] The temperature change of LDO is detected by NTC. When the voltage difference is large and the current rises to a certain level, the temperature will rise sharply. At this time, NTC will detect that the temperature has increased, the resistance value will drop sharply, and the resistance value will exceed the voltage division threshold voltage.

[0018] When the comparator outputs a high level, the circuit output will automatically switch from the default LDO mode to the DC / DC mode. When the temperature drops to a certain level, it will automatically switch back to the LDO mode. At this time, if the current is still relatively large.

[0019] It will switch to DC / DC mode repeatedly, and the judgment will be repeated in this way, eventually controlling the temperature efficiency of the entire system within a certain range. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 This is a structural diagram of this application;

[0022] Figure 2 This is the circuit diagram of this application. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] As the instruction manual Figure 1 As shown, a high-voltage difference, high-efficiency, wide-current and low-quiescent-current circuit is externally connected to an input voltage, and includes a low-power voltage regulator circuit, a switching voltage regulator circuit, a switching switch circuit and a comparison circuit. The VIN terminals of the low-power voltage regulator circuit and the switching voltage regulator circuit are powered by the input voltage, the input of the comparison circuit is connected to a reference voltage and a thermistor, the output terminal of the comparison circuit is connected to an enable terminal of the switching voltage regulator circuit, the output terminals of the switching voltage regulator circuit and the low-power voltage regulator circuit are connected to a switching switch circuit, and the output terminal of the switching switch circuit serves as the total output terminal of the circuit.

[0025] Under normal circumstances in this application, the temperature is at a relatively low value, and it is in LDO mode at this time. The current circuit is powered by a static voltage regulator. When the input voltage difference is large and the current rises to a certain level, the temperature in the system rises, which is sensed by the thermistor and fed back to the comparison circuit. After the temperature rises, the resistance of the thermistor decreases, the voltage divider decreases, the in-phase input of the comparator increases, and the comparator output changes from 0 to 1, then the control switching circuit is switched, the low-power voltage regulator is disconnected, and the switching voltage regulator is turned on, thereby realizing the state switching. When the temperature returns to the normal threshold, the in-phase voltage divider of the comparison circuit decreases, and the comparison circuit output changes from 1 to 0, then the switching voltage regulator is controlled to be turned off, and the switching switch is switched to short the switching voltage regulator and turn on the low-power voltage regulator.

[0026] As stated in the attached Figure 2 As shown, the low power voltage regulator circuit includes a low power voltage regulator, a VIN pin of the low power voltage regulator is connected to an input voltage, and capacitors are connected in series between the input and output of the low power voltage regulator and the power ground.

[0027] The low-dropout linear regulator is a new generation of integrated circuit regulator. The biggest difference between it and the three-terminal regulator is that the low-dropout linear regulator is a micro-chip system with very low self-consumption. It can be used for current main channel control. The chip integrates hardware circuits such as MOSFET with extremely low on-line on-resistance, Schottky diode, sampling resistor and voltage divider resistor, and has over-current protection, over-temperature protection, precision reference source, differential amplifier, delay device and other functions.

[0028] The switching regulator circuit includes a switching regulator, a VIN pin of the switching regulator is connected to an input voltage, an enable terminal of the switching regulator is connected to an output of a comparison circuit, a SW pin of the switching regulator serves as an output of the switching regulator circuit, and a BST pin of the switching regulator is connected to the SW pin via a capacitor C3.

[0029] The SW pin of the switching regulator is connected to an inductor L1, and the other end of the inductor L1 is connected to a capacitor and a resistor connected in parallel with the power ground, and a voltage regulator D1 is connected between the SW pin of the switching regulator and the power ground. The inductor L1 plays a filtering role, and the voltage regulator D1 can ensure the stability of the output voltage of the switching regulator.

[0030] A switching regulator uses an output stage that repeatedly switches between "on" and "off" states, along with energy storage components (capacitors and inductors) to produce an output voltage. It is regulated by adjusting the switching timing based on feedback samples of the output voltage.

[0031] The comparison circuit includes a comparator, a thermistor NTC1 and a resistor R4 are connected in series between the in-phase terminal of the comparator and the reference voltage, and the output terminal of the comparator is connected to the enable terminal of the switch voltage regulator circuit. The switching switch circuit includes multiple switch tubes, and the controlled end of the switching switch circuit is connected to the output end of the comparison circuit. When the switching switch circuit is connected to the low-power voltage regulator circuit, the switching voltage regulator circuit is disconnected, and the low-power voltage regulator circuit is used as the total output; when the switching switch circuit short-circuits the low-power voltage regulator circuit, the switching voltage regulator circuit is connected, and the switching voltage regulator circuit is used as the total output. The switching circuit includes MOSFETs Q1-Q3, MOSFETs Q1 and Q2 are pmos, MOSFET Q3 is nmos, the gates of MOSFETs Q1 and Q3 are connected to the output of the comparison circuit, the source of MOSFET Q1 is connected to the output of the low-power voltage regulator circuit, the source of MOSFET Q2 is connected to the output of the switching voltage regulator circuit, the drains of MOSFET Q1 and MOSFET Q2 are connected in parallel as the total output, the gate of MOSFET Q2 is connected to the drain of MOSFET Q3, and the source of MOSFET Q3 is grounded.

[0032] The thermistor NTC1 senses the temperature of the LDO. When the temperature rises too much, it means that the current increases, indicating that the system needs to switch modes and feedback is given to the comparator. Through the change of the comparator output, the controller switches the state of the MOS tube in the switch circuit to achieve the change of the system output.

[0033] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high voltage difference, high efficiency, wide current and low quiescent current circuit, the circuit is externally connected to an input voltage, characterized in that: It includes a low-power voltage stabilizing circuit, a switching voltage stabilizing circuit, a switching switch circuit and a comparison circuit. The VIN terminals of the low-power voltage stabilizing circuit and the switching voltage stabilizing circuit are powered by an input voltage. The input of the comparison circuit is connected to a reference voltage and a thermistor. The output terminal of the comparison circuit is connected to an enable terminal of the switching voltage stabilizing circuit. The output terminals of the switching voltage stabilizing circuit and the low-power voltage stabilizing circuit are connected to a switching switch circuit. The output terminal of the switching switch circuit serves as the total output terminal of the circuit.

2. A high voltage difference, high efficiency, wide current and low quiescent current circuit according to claim 1, characterized in that: The low-power voltage stabilizing circuit comprises a low-power voltage stabilizer, a VIN pin of the low-power voltage stabilizer is connected to an input voltage, and capacitors are connected in series between the input and output of the low-power voltage stabilizer and the power ground.

3. A high voltage difference, high efficiency, wide current and low quiescent current circuit according to claim 1, characterized in that: The switching regulator circuit includes a switching regulator, a VIN pin of the switching regulator is connected to an input voltage, an enable terminal of the switching regulator is connected to the output of the comparison circuit, a SW pin of the switching regulator serves as the output of the switching regulator circuit, and a BST pin of the switching regulator is connected to the SW pin via a capacitor C3.

4. A high voltage difference, high efficiency, wide current and low quiescent current circuit according to claim 3, characterized in that: The SW pin of the switching regulator is connected to an inductor L1, a capacitor and a resistor connected in parallel are connected between the other end of the inductor L1 and the power ground, and a voltage regulator D1 is connected between the SW pin of the switching regulator and the power ground.

5. A high voltage difference, high efficiency, wide current and low quiescent current circuit according to claim 1, characterized in that: The comparison circuit comprises a comparator, a thermistor NTC1 and a resistor R4 are connected in series between the in-phase terminal of the comparator and the reference voltage, and the output terminal of the comparator is connected to the enable terminal of the switching voltage regulator circuit.

6. A high voltage difference, high efficiency, wide current and low quiescent current circuit according to claim 1, characterized in that: The switching switch circuit includes multiple switching tubes, and the controlled end of the switching switch circuit is connected to the output end of the comparison circuit. When the switching switch circuit connects to the low-power voltage regulator circuit, the switching voltage regulator circuit is disconnected, and the low-power voltage regulator circuit is used as the total output; when the switching switch circuit short-circuits the low-power voltage regulator circuit, the switching voltage regulator circuit is connected, and the switching voltage regulator circuit is used as the total output.

7. A high voltage difference, high efficiency, wide current and low quiescent current circuit according to claim 6, characterized in that: The switching circuit includes MOSFETs Q1-Q3, wherein the MOSFETs Q1 and Q2 are pmos, the MOSFET Q3 is nmos, the gates of the MOSFETs Q1 and Q3 are connected to the output of the comparison circuit, the source of the MOSFET Q1 is connected to the output of the low-power voltage regulator circuit, the source of the MOSFET Q2 is connected to the output of the switching voltage regulator circuit, the drains of the MOSFET Q1 and the MOSFET Q2 are connected in parallel as a total output, the gate of the MOSFET Q2 is connected to the drain of the MOSFET Q3, and the source of the MOSFET Q3 is grounded.

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