Low cost charge pump driven high side NMOS circuit

Abstract

The utility model discloses a low -cost charge pump drive high side NMOS circuit relates to the field of using electricity, and this low -cost charge pump drive high side NMOS circuit includes: charge pump drive control module is used to receive the square wave signal from MCU, and square wave signal carries out level conversion and amplification, compared with prior art, the beneficial effects of the utility model are: the utility model constructs the stable and reliable charge pump boost circuit, does not need boost inductance, and voltage can control, the peripheral circuit is very simple, and is composed of common diode, transistor, and low cost, when not needing driving high side NMOS, the leakage current is 0, can fully satisfy the lithium battery long time standby requirement, and the expandability is strong, and the adjustable voltage dividing resistor is suitable for different string number battery or voltage, can drive multiple high side NMOS simultaneously, and compared with the special charge pump drive IC on the market has great cost advantage, and the cost is saved at least 2 / 3 compared with cost.

Description

Technical Field

[0001] This utility model relates to the field of electricity, specifically a low-cost charge pump driven high-side NMOS circuit. Background Technology

[0002] In applications such as vacuum cleaners, floor scrubbers, sweepers, two-wheeled electric vehicles, scooters, battery swapping, smart homes, electric vehicles, drones, and energy storage batteries, it is often necessary to control the on / off state of the positive terminal of the power supply. Currently, the industry generally adopts two solutions: one is to use a P-channel MOSFET (PMOS) as a high-voltage side switch, and the other is to use an N-channel MOSFET (NMOS) in conjunction with a dedicated charge pump driver integrated circuit (IC).

[0003] For PMOS solutions, the on-resistance is typically high, resulting in limited overcurrent capability, fewer available models, and relatively high prices. For NMOS solutions using dedicated charge pump driver ICs, while the performance is excellent, the dedicated charge pump driver ICs themselves are expensive, increasing system costs. Furthermore, this market is mainly dominated by imported components, posing supply chain risks.

[0004] In summary, the existing solutions for controlling the positive terminal of the power supply are too expensive and need to be improved. Utility Model Content

[0005] The purpose of this invention is to provide a low-cost charge pump driven high-side NMOS circuit to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A low-cost charge pump driven high-side NMOS circuit includes:

[0008] The charge pump drive control module is used to receive a square wave signal (Pump_PWM) from the MCU (1kHz, 5% duty cycle), and perform level conversion and amplification on the square wave signal to provide a stable and controlled bias voltage for the subsequent charge pump push-pull drive module, thereby accurately starting or stopping the boost operation of the charge pump.

[0009] The charge pump push-pull drive module is used to adjust the charging status of the capacitor (capacitor C5) based on the bias voltage. Through the superposition effect of capacitor charging and voltage, the input battery voltage is effectively raised to a higher stable voltage (such as about 39.5V) to drive the high-side NMOS (MOSFETs Q1 and Q2).

[0010] The high-side NMOS switch module is used to control the high-side NMOS to turn on and off according to the MCU's enable signal (MOS_EN);

[0011] The high-side NMOS push-pull control module is used to assist the high-side NMOS switching module, accelerate the turn-on and turn-off process of the high-side NMOS, and improve the switching speed.

[0012] The output of the charge pump drive control module is connected to the input of the charge pump push-pull drive module. The output of the charge pump push-pull drive module is connected to the input of the high-side NMOS switch module and the first input of the high-side NMOS push-pull control module. The output of the high-side NMOS switch module is connected to the second input of the high-side NMOS push-pull control module.

[0013] As a further improvement of this utility model: the charge pump drive control module includes transistors Q5 and Q9. The emitter of transistor Q5 is supplied with a power supply voltage (here powered by 6 lithium batteries). The emitter of transistor Q5 is connected to one end of resistor R7. The other end of resistor R7 is connected to the base of transistor Q5 and one end of resistor R10. The collector of transistor Q5 is connected to the input terminal of the charge pump push-pull drive module. The other end of resistor R10 is connected to the collector of transistor Q9. The emitter of transistor Q9 is grounded. The base of transistor Q9 receives the square wave signal Pump_PWM from the MCU through resistor R13.

[0014] As a further embodiment of this utility model: the charge pump push-pull drive module includes transistors Q6 and Q8. The base of transistor Q6 is connected to the base of transistor Q8, the negative terminal of Zener diode Z2, one end of resistor R12, and one end of resistor R8. The other end of resistor R8 is connected to the output terminal of the charge pump drive control module. The other end of resistor R12 is grounded. The positive terminal of Zener diode Z2 is grounded. The collector of transistor Q8 is grounded. The emitter of transistor Q8 is connected to the emitter of transistor Q6 and one end of capacitor C5. The collector of transistor Q6 is connected to one end of resistor R4 and the positive terminal of diode D2. The other end of resistor R4 is supplied with the power supply voltage. The negative terminal of diode D2 is connected to the other end of capacitor C5 and the positive terminal of diode D3. The negative terminal of diode D3 is connected to one end of capacitor C6, the input terminal of the high-side NMOS switch module, and the first input terminal of the high-side NMOS push-pull control module. The other end of capacitor C6 is grounded.

[0015] As a further embodiment of this invention: the high-side NMOS switching module includes transistors Q7 and Q10. The base of transistor Q10 is connected to the MCU's enable signal MOS_EN through resistor R16. The emitter of transistor Q10 is grounded. The collector of transistor Q10 is connected to one end of resistor R14. The other end of resistor R14 is connected to one end of resistor R11 and the base of transistor Q7. The emitter of transistor Q7 is connected to the other end of resistor R11 and the output terminal of the charge pump push-pull drive module. The collector of transistor Q7 is connected to the second input terminal of the high-side NMOS push-pull control module.

[0016] As a further embodiment of this utility model: the high-side NMOS push-pull control module includes transistors Q3 and Q4. The emitter of transistor Q3 is connected to the emitter of transistor Q4. The emitter of transistor Q3 is connected to the gate (G) of the high-side NMOS (Q1, Q2) through a resistor. The collector of transistor Q3 is connected to the output terminal of the charge pump push-pull drive module through resistor R5. The base of transistor Q3 is connected to the base of transistor Q4 and one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R9 and the output terminal of the high-side NMOS switching module. The other end of resistor R9 is connected to the source (S) of the high-side NMOS (Q1, Q2).

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model constructs a stable and reliable charge pump boost circuit, which does not require a boost inductor and the voltage can be controlled; the peripheral circuit is very simple, composed of commonly used diodes and transistors, and the cost is low; the leakage current is 0 when there is no need to drive the high-side NMOS, which can fully meet the long-term standby requirements of lithium batteries; it has strong scalability, and the voltage divider resistor can be adjusted to adapt to different battery series numbers or voltages; it can drive multiple high-side NMOS at the same time, which has a great cost advantage compared with dedicated charge pump driver ICs on the market (commercial charge pump ICs can generally only drive two channels, one for charging and one for discharging), saving at least 2 / 3 of the cost. Attached Figure Description

[0018] Figure 1 This is a circuit diagram of a low-cost charge pump driven high-side NMOS circuit. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1 A low-cost charge pump driven high-side NMOS circuit includes:

[0021] The charge pump drive control module is used to receive a square wave signal (Pump_PWM) from the MCU (1kHz, 5% duty cycle), and perform level conversion and amplification on the square wave signal to provide a stable and controlled bias voltage for the subsequent charge pump push-pull drive module, thereby accurately starting or stopping the boost operation of the charge pump.

[0022] The charge pump push-pull drive module is used to adjust the charging status of the capacitor (capacitor C5) based on the bias voltage. Through the superposition effect of capacitor charging and voltage, the input battery voltage is effectively raised to a higher stable voltage (such as about 39.5V) to drive the high-side NMOS (MOSFETs Q1 and Q2).

[0023] The high-side NMOS switch module is used to control the high-side NMOS to turn on and off according to the MCU's enable signal (MOS_EN);

[0024] The high-side NMOS push-pull control module is used to assist the high-side NMOS switching module, accelerate the turn-on and turn-off process of the high-side NMOS, and improve the switching speed.

[0025] The output of the charge pump drive control module is connected to the input of the charge pump push-pull drive module. The output of the charge pump push-pull drive module is connected to the input of the high-side NMOS switch module and the first input of the high-side NMOS push-pull control module. The output of the high-side NMOS switch module is connected to the second input of the high-side NMOS push-pull control module.

[0026] In a specific embodiment: Please refer to Figure 1 The example is a 6-cell charge pump circuit. The number of lithium batteries can be increased or decreased depending on the application. The voltage divider resistors can be adjusted appropriately. The following content explains the principle based on a 6-cell lithium battery power supply.

[0027] In this embodiment: Please refer to Figure 1 The charge pump drive control module includes transistors Q5 and Q9. The emitter of transistor Q5 is supplied with the power supply voltage (here powered by 6 lithium batteries). The emitter of transistor Q5 is connected to one end of resistor R7. The other end of resistor R7 is connected to the base of transistor Q5 and one end of resistor R10. The collector of transistor Q5 is connected to the input terminal of the charge pump push-pull drive module. The other end of resistor R10 is connected to the collector of transistor Q9. The emitter of transistor Q9 is grounded. The base of transistor Q9 receives the square wave signal Pump_PWM from the MCU through resistor R13.

[0028] The MCU outputs a 1kHz square wave signal Pump_PWM with a 5% duty cycle to control the conduction status of transistor Q9. When transistor Q9 is on, the base level of transistor Q5 is pulled low, transistor Q5 is on, and outputs a bias voltage of 25.2V to the charge pump push-pull drive module.

[0029] In this embodiment: Please refer to Figure 1The charge pump push-pull drive module includes transistors Q6 and Q8. The base of transistor Q6 is connected to the base of transistor Q8, the negative terminal of Zener diode Z2, one end of resistor R12, and one end of resistor R8. The other end of resistor R8 is connected to the output terminal of the charge pump drive control module. The other end of resistor R12 is grounded. The positive terminal of Zener diode Z2 is grounded. The collector of transistor Q8 is grounded. The emitter of transistor Q8 is connected to the emitter of transistor Q6 and one end of capacitor C5. The collector of transistor Q6 is connected to one end of resistor R4 and the positive terminal of diode D2. The other end of resistor R4 is supplied with the power supply voltage. The negative terminal of diode D2 is connected to the other end of capacitor C5 and the positive terminal of diode D3. The negative terminal of diode D3 is connected to one end of capacitor C6, the input terminal of the high-side NMOS switch module, and the first input terminal of the high-side NMOS push-pull control module. The other end of capacitor C6 is grounded.

[0030] Transistor Q5 provides a bias voltage of 25.2V, which is then divided by resistors R8 and R12 to obtain 2 / 3 of the voltage, approximately 16.8V. This voltage is then clamped to 15V by the 15V Zener diode Z2, providing the bias drive voltage for transistor Q6 and charging the lower end of capacitor C5. (When not charged, the voltage across capacitor C5 is approximately 25.2V - 0.7V = 24.5V).

[0031] When the base of transistor Q6 has a voltage of 15V, the emitter of transistor Q6 receives 15V - 0.7V = 14.3V, which charges the lower end of capacitor C5. Utilizing the principle that the voltage across a capacitor cannot change abruptly, the voltage is boosted, and the final voltage of the upper end of capacitor C5 to ground is 39.5V. The maximum voltage of capacitor C6 is approximately 39.5V - 0.7V = 38.8V.

[0032] In this embodiment: Please refer to Figure 1 The high-side NMOS switching module includes transistors Q7 and Q10. The base of transistor Q10 is connected to the MCU's enable signal MOS_EN through resistor R16. The emitter of transistor Q10 is grounded. The collector of transistor Q10 is connected to one end of resistor R14. The other end of resistor R14 is connected to one end of resistor R11 and the base of transistor Q7. The emitter of transistor Q7 is connected to the other end of resistor R11 and the output of the charge pump push-pull drive module. The collector of transistor Q7 is connected to the second input of the high-side NMOS push-pull control module.

[0033] When MOS_EN is high, transistor Q10 is turned on, pulling down the base voltage of transistor Q7, which in turn turns on Q7. This, through the high-side NMOS push-pull control module, accelerates the turn-on of the high-side NMOS (Q1, Q2). If there is no high-side NMOS push-pull control module, the collector of transistor Q7 is connected to the gate of the high-side NMOS (Q1, Q2) through a resistor, and the output voltage drives the high-side NMOS (Q1, Q2) to turn on. When the base of transistor Q10 is high, the high-side NMOS is turned on; when the base of transistor Q10 is low, the high-side NMOS is turned off.

[0034] In this embodiment: Please refer to Figure 1 The high-side NMOS push-pull control module includes transistors Q3 and Q4. The emitter of transistor Q3 is connected to the emitter of transistor Q4. The emitter of transistor Q3 is connected to the gate (G) of the high-side NMOS (Q1, Q2) through a resistor. The collector of transistor Q3 is connected to the output terminal of the charge pump push-pull drive module through resistor R5. The base of transistor Q3 is connected to the base of transistor Q4 and one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R9 and the output terminal of the high-side NMOS switching module. The other end of resistor R9 is connected to the source (S) of the high-side NMOS (Q1, Q2).

[0035] When transistor Q7 is turned on, it causes transistor Q3 to turn on as well. A large current is drawn directly from the high voltage (39.5V) generated by the charge pump through a very small resistor R5, which quickly charges the gate capacitance of the high-side NMOS (Q1, Q2), thus turning on the high-side NMOS quickly.

[0036] The working principle of this utility model is as follows: The charge pump drive control module receives a square wave signal (Pump_PWM) from the MCU (1kHz, 5% duty cycle) and performs level conversion and amplification on the square wave signal to provide a stable and controlled bias voltage for the subsequent charge pump push-pull drive module, thereby accurately starting or stopping the boost operation of the charge pump; the charge pump push-pull drive module adjusts the charging status of the capacitor (capacitor C5) based on the bias voltage, and through the superposition effect of capacitor charging and voltage, effectively raises the input battery voltage to a higher stable voltage (such as about 39.5V) to drive the high-side NMOS (MOSFETs Q1 and Q2); the high-side NMOS switching module controls the conduction and cutoff of the high-side NMOS according to the MCU's enable signal (MOS_EN); the high-side NMOS push-pull control module assists the high-side NMOS switching module, accelerates the turn-on and turn-off process of the high-side NMOS, and improves the switching speed.

[0037] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-cost charge pump driven high-side NMOS circuit, characterized in that, This low-cost charge pump-driven high-side NMOS circuit includes: The charge pump drive control module is used to receive square wave signals from the MCU, and to perform level conversion and amplification of the square wave signals to provide a stable and controlled bias voltage for the subsequent charge pump push-pull drive module, thereby accurately starting or stopping the boost operation of the charge pump. The charge pump push-pull drive module is used to adjust the capacitor charging status based on the bias voltage. Through the superposition effect of capacitor charging and voltage, the input battery voltage is effectively raised to a higher stable voltage to drive the high-side NMOS. The high-side NMOS switch module is used to control the conduction and cutoff of the high-side NMOS according to the MCU's enable signal; The high-side NMOS push-pull control module is used to assist the high-side NMOS switching module, accelerate the turn-on and turn-off process of the high-side NMOS, and improve the switching speed. The output of the charge pump drive control module is connected to the input of the charge pump push-pull drive module. The output of the charge pump push-pull drive module is connected to the input of the high-side NMOS switch module and the first input of the high-side NMOS push-pull control module. The output of the high-side NMOS switch module is connected to the second input of the high-side NMOS push-pull control module.

2. The low-cost charge pump driven high-side NMOS circuit according to claim 1, characterized in that, The charge pump drive control module includes transistors Q5 and Q9. The emitter of transistor Q5 is supplied with the power supply voltage. The emitter of transistor Q5 is connected to one end of resistor R7. The other end of resistor R7 is connected to the base of transistor Q5 and one end of resistor R10. The collector of transistor Q5 is connected to the input terminal of the charge pump push-pull drive module. The other end of resistor R10 is connected to the collector of transistor Q9. The emitter of transistor Q9 is grounded. The base of transistor Q9 receives the square wave signal Pump_PWM from the MCU through resistor R13.

3. The low-cost charge pump driven high-side NMOS circuit according to claim 1, characterized in that, The charge pump push-pull drive module includes transistors Q6 and Q8. The base of transistor Q6 is connected to the base of transistor Q8, the negative terminal of Zener diode Z2, one end of resistor R12, and one end of resistor R8. The other end of resistor R8 is connected to the output terminal of the charge pump drive control module. The other end of resistor R12 is grounded. The positive terminal of Zener diode Z2 is grounded. The collector of transistor Q8 is grounded. The emitter of transistor Q8 is connected to the emitter of transistor Q6 and one end of capacitor C5. The collector of transistor Q6 is connected to one end of resistor R4 and the positive terminal of diode D2. The other end of resistor R4 is supplied with the power supply voltage. The negative terminal of diode D2 is connected to the other end of capacitor C5 and the positive terminal of diode D3. The negative terminal of diode D3 is connected to one end of capacitor C6, the input terminal of the high-side NMOS switch module, and the first input terminal of the high-side NMOS push-pull control module. The other end of capacitor C6 is grounded.

4. The low-cost charge pump driven high-side NMOS circuit according to claim 1, characterized in that, The high-side NMOS switching module includes transistors Q7 and Q10. The base of transistor Q10 is connected to the MCU's enable signal MOS_EN through resistor R16. The emitter of transistor Q10 is grounded. The collector of transistor Q10 is connected to one end of resistor R14. The other end of resistor R14 is connected to one end of resistor R11 and the base of transistor Q7. The emitter of transistor Q7 is connected to the other end of resistor R11 and the output of the charge pump push-pull drive module. The collector of transistor Q7 is connected to the second input of the high-side NMOS push-pull control module.

5. The low-cost charge pump driven high-side NMOS circuit according to claim 4, characterized in that, The high-side NMOS push-pull control module includes transistors Q3 and Q4. The emitter of transistor Q3 is connected to the emitter of transistor Q4. The emitter of transistor Q3 is connected to the gate (G) of the high-side NMOS through a resistor. The collector of transistor Q3 is connected to the output terminal of the charge pump push-pull drive module through resistor R5. The base of transistor Q3 is connected to the base of transistor Q4 and one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R9 and the output terminal of the high-side NMOS switching module. The other end of resistor R9 is connected to the source (S) of the high-side NMOS.

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