Floating power supply generating circuit for driving circuit and integrated circuit chip

Abstract

The invention discloses a floating power supply generating circuit for a driving circuit. The floating power supply generating circuit comprises a current mirror module, a source following module, a direct current source module, a first resistor, a floating ground reference end, a floating power supply output end and a high-voltage protection module. The current mirror module receives and mirrors the reference current, so that the mirrored current flows through the first resistor and generates voltage drop. The direct current source module provides a reference current. The source following module is electrically connected to the first resistor, superposes the voltage drop on the first resistor and the voltage of the floating ground reference end, and then outputs the voltage. The high-voltage protection module is used for discharge and protection. The floating power supply output end changes along with the floating ground reference end, at least one of the resistance value of the first resistor, the reference current and the mirror image proportion of the current mirror module is adjusted, and the voltage of the floating power supply output end is adjusted. Accurate following and dynamic compensation of the floating ground potential by the output voltage are achieved, and it is guaranteed that the power tube obtains stable driving voltage all the time when the floating ground changes.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a floating power supply generation circuit for drive circuits. Background Technology

[0002] Currently, in power electronics, especially in automotive LED drivers, the driver circuit needs to convert the control signal to the floating power domain required by the power transistor. However, changes in the external switching state cause the voltage of the relevant node where the power transistor control node is located to fluctuate. If the internal power supply of the driver circuit cannot change synchronously with the floating potential, it will affect the normal control of the power transistor.

[0003] Existing floating power supply generation schemes struggle to balance potential tracking and adjustability. While current schemes can achieve basic floating power supply, they lack flexible programming adjustment capabilities, making it difficult to guarantee the stable operation of the drive circuit and the safety of devices. Therefore, a scheme is needed that can generate a stable and adjustable power supply that can track the floating ground potential, and has the ability to compensate for the effects of non-ideal factors, in order to meet the requirements of high reliability. Summary of the Invention

[0004] The purpose of this invention is to provide a floating power supply generation circuit for a drive circuit to solve the problems of insufficient flexibility and limited adjustment capability in existing floating power supply generation schemes. Through the floating power supply generation circuit for a drive circuit of this invention, the output voltage achieves precise tracking and dynamic compensation of the floating ground potential, effectively reducing non-ideal deviations, ensuring that the power transistor always obtains a stable drive voltage when the floating ground changes, and improving reliability.

[0005] In a first aspect, the present invention provides a floating power supply generation circuit for a driving circuit, comprising a current mirror module, a source follower module, a DC current source module, a first resistor, a floating ground reference terminal, a floating power supply output terminal, and a high-voltage protection module. The first terminal of the current mirror module is electrically connected to a first voltage source, the second terminal is electrically connected to the source follower module, and the third terminal is electrically connected to the first terminal of the DC current source module. The current mirror module receives and mirrors a reference current, causing the mirrored current to flow through the first resistor and generate a voltage drop. The second terminal of the DC current source module is electrically connected to the first terminal of the high-voltage protection module, providing a reference current. The first resistor is electrically connected between the source follower module and the high-voltage protection module. The second terminal of the source follower module is electrically connected to the first terminal of the first resistor, serving to buffer and output the voltage drop across the first resistor after superimposing it with the voltage at the floating ground reference terminal. The third terminal of the source follower module is electrically connected to both the floating power supply output terminal and the high-voltage protection module. The second terminal of the high-voltage protection module is electrically connected to the second terminal of the first resistor, and the third and fourth terminals are electrically connected to the floating ground reference terminal and the floating power supply output terminal, respectively, for leakage and overvoltage protection. The floating ground reference terminal is connected to the load, and the floating power supply output terminal changes with the floating ground reference terminal. By adjusting at least one of the following: the resistance value of the first resistor, the reference current, and the mirror ratio of the current mirror module, the voltage of the floating power supply output terminal is adjusted, and the floating power supply output terminal supplies floating power to the load.

[0006] Furthermore, the current mirror module includes a first PMOS transistor and a second PMOS transistor. The source of the second PMOS transistor is electrically connected to the first voltage source, its gate is connected to the gate of the first PMOS transistor and its own drain, and its drain is electrically connected to the source of a fourth PMOS transistor. The source of the first PMOS transistor is electrically connected to the source follower module, and its drain is electrically connected to the source of a third PMOS transistor. The gate of the fourth PMOS transistor is connected to the gate of the third PMOS transistor and its own drain, and its drain is electrically connected to the first terminal of the DC current source module. The drain of the third PMOS transistor is electrically connected to the source follower module. The fourth and third PMOS transistors are used to protect the first and second PMOS transistors when the voltage at the floating ground reference terminal changes. The mirror ratio of the current mirror module is determined by the size ratio of the first and second PMOS transistors, and the current in the branch of the first PMOS transistor is the product of the reference current and the mirror ratio.

[0007] Furthermore, the source follower module includes a first NMOS transistor and a second NMOS transistor. The first NMOS transistor is connected in a diode configuration, with its source electrically connected to the first terminal of the first resistor, its gate connected to its own drain and also connected to the gate of the second NMOS transistor, and its drain electrically connected to the drain of the third PMOS transistor. The second NMOS transistor is connected in a source follower configuration, with its source electrically connected to the floating power supply output terminal, its drain electrically connected to the source of the first PMOS transistor, and its gate electrically connected to the drain of the third PMOS transistor. The source follower module receives the superimposed signal of the voltage drop across the first resistor and the floating ground reference voltage through the first NMOS transistor, and then outputs it to the floating power supply output terminal after voltage buffering by the second NMOS transistor.

[0008] Furthermore, the high-voltage protection module includes: a fifth PMOS transistor, whose source is electrically connected to the floating power supply output terminal, whose drain is electrically connected to the floating ground reference terminal, and whose gate is electrically connected between the drain of the first NMOS transistor and the gate of the second NMOS transistor; and a Zener diode, whose cathode is electrically connected to the floating power supply output terminal, and whose anode is electrically connected to the second terminal of the first resistor. The fifth PMOS transistor is used to drain current from the floating power supply output terminal during voltage jumps, and the Zener diode is used to clamp protection when the voltage at the floating power supply output terminal abnormally rises.

[0009] Furthermore, the high-voltage protection module also includes: a sixth PMOS transistor, whose source is electrically connected to the second terminal of the first resistor, whose gate is electrically connected to the floating ground reference terminal, and whose drain is electrically connected to the DC current source module, for clamping the potential of the second terminal of the first resistor to the potential of the floating ground reference terminal.

[0010] Furthermore, the DC current source module includes: a third NMOS transistor, the source of which is electrically connected to the negative terminal of the DC current source module, and the drain of which is connected to the drain of a fourth PMOS transistor. Its gate is connected to a fixed bias voltage for protecting the DC current source module. The positive terminal of the DC current source module is grounded.

[0011] Furthermore, the first resistor is a variable resistor.

[0012] Furthermore, the voltage at the output of the floating power supply satisfies the following formula: VOUT = Ib*n*r1 + Vagnd_float + Vd, where Ib is the reference current, n is the mirror ratio of the current mirror module, r1 is the resistance of the first resistor, Vagnd_float is the voltage at the floating ground reference terminal, and Vd is the non-ideal voltage deviation. By compensating for the influence of the non-ideal voltage deviation on the output voltage, the voltage difference between the output of the floating power supply and the floating ground reference terminal is stabilized.

[0013] Furthermore, the method of adjusting the floating power supply output terminal includes a first programming method: adjusting the resistance value of the first resistor through a digital decoder. The control signal of the digital decoder is converted from the low-voltage power supply domain to the floating power supply domain with the floating ground reference terminal as the reference via a level conversion circuit. By adjusting the resistance value of the first resistor, the voltage drop across the first resistor is changed, which is used to dynamically adjust the voltage of the floating power supply output terminal.

[0014] Furthermore, the method of adjusting the output of the floating power supply includes a second programming method: by adjusting the magnitude of the reference current generated by the DC current source module, the current flowing through the first resistor is changed, which is used to change the voltage drop across the first resistor, thereby dynamically adjusting the voltage at the output of the floating power supply.

[0015] On the other hand, the present invention also provides an integrated circuit chip, comprising:

[0016] The floating power supply generating circuit for the drive circuit described in any one of the first aspects.

[0017] Compared with the prior art, the present invention achieves precise tracking and dynamic compensation of the output voltage to the floating ground potential through the floating power generation circuit used in the drive circuit, effectively reducing non-ideal deviations, ensuring that the power transistor always obtains a stable drive voltage when the floating ground changes, and improving reliability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a floating power supply generating circuit for a driving circuit in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a load circuit according to an embodiment of the present invention;

[0020] Figure 3 This is another schematic diagram of a floating power supply generating circuit for a driving circuit in an embodiment of the present invention;

[0021] Figure 4 This is another schematic diagram of a floating power supply generation circuit for a driving circuit in an embodiment of the present invention.

[0022] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0023] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0024] This circuit is used in the driving system of automotive LED lights to provide a stable floating power supply for the driver circuit.

[0025] Example:

[0026] This embodiment provides a floating power supply generation circuit for a drive circuit. Please refer to [link to relevant documentation]. Figure 1 The system includes a current mirror module 1, a source follower module 2, a DC current source module 4, a first resistor R1, a floating ground reference terminal AGND_FLOAT, a floating power supply output terminal VOUT, and a high-voltage protection module 3. The first terminal of the current mirror module 1 is electrically connected to the first voltage source VCCA, the second terminal is electrically connected to the source follower module 2, and the third terminal is electrically connected to the first terminal of the DC current source module 4. The current mirror module 1 receives and mirrors the reference current Ib, causing the mirrored current to flow through the first resistor R1 and generate a voltage drop. The second terminal of the DC current source module 4 is electrically connected to the first terminal of the high-voltage protection module 3 to provide the reference current. The first resistor R1 is electrically connected between the source follower module 2 and the high-voltage protection module 3. The second terminal of the source follower module 2 is electrically connected to the first terminal of the first resistor R1, used to perform voltage buffering and output after superimposing the voltage drop across the first resistor R1 and the voltage at the floating ground reference terminal AGND_FLOAT. The third terminal of the source follower module 2 is electrically connected to both the floating power supply output terminal VOUT and the high-voltage protection module 3. The second terminal of the high-voltage protection module 3 is electrically connected to the second terminal of the first resistor R1. The third and fourth terminals are electrically connected to the floating ground reference terminal AGND_FLOAT and the floating power supply output terminal VOUT, respectively, for leakage current and overvoltage protection. The floating ground reference terminal AGND_FLOAT is connected to the load. The floating power supply output terminal VOUT changes with the floating ground reference terminal AGND_FLOAT. By adjusting at least one of the following: the resistance value of the first resistor R1, the reference current Ib, and the mirror ratio n of the current mirror module 1, the voltage of the floating power supply output terminal VOUT is adjusted, and the floating power supply output terminal VOUT supplies floating power to the load.

[0027] The DC current source module 4 provides a reference current Ib. After the reference current Ib flows into the current mirror module 1, it is mirrored. By adjusting the size ratio of the components in the current mirror module 1, the mirrored current n*Ib flows through the first resistor R1, where n is the mirror ratio n of the current mirror module 1. This mirror ratio n is related to the size ratio of the components in the current mirror module 1, thereby generating an adjustable voltage drop across the first resistor R1. The second terminal of the source follower module 2 receives the voltage drop across the first resistor R1 and the voltage of the floating ground reference terminal AGND_FLOAT, performs buffering, and then transmits the processed voltage to the floating power supply output terminal VOUT. The high-voltage protection module 3 functions as a current discharge and overvoltage protection unit. When the voltage at the floating power supply output terminal VOUT experiences an abnormal jump, the high-voltage protection module 3 can release excess current. Simultaneously, when the floating power supply output terminal VOUT becomes abnormally high, it can clamp the voltage within a safe range. The floating ground reference terminal AGND_FLOAT uses the load cathode potential as the reference ground potential for the entire floating power supply, ensuring that the voltage at the floating power supply output terminal VOUT follows the potential changes of the floating ground reference terminal AGND_FLOAT. By adjusting at least one of the following three parameters—the resistance value of the first resistor R1, the reference current Ib provided by the DC current source module 4, and the mirror ratio n of the current mirror module 1—the voltage value at the floating power supply output terminal VOUT can be adjusted, providing a stable floating power supply to the load.

[0028] In actual cases, please refer to Figure 2 and Figure 3 . Figure 2 This is a schematic diagram of the load, which can be the LED assembly of a vehicle headlight. The LED assembly includes a driver circuit. The driver circuit converts the PWM signals (a0, a1, a2) from the 0V~5.5V power supply domain into a floating power supply domain that can properly control the Ma, Mb, and Mc power transistors. When the switching states of Da, Db, and Dc change, the voltages of all nodes A~B float. The floating power supply output terminal VOUT is connected to the driver circuit, and the floating ground reference terminal AGND_FLOAT is connected to the cathode of the LED assembly, ensuring that the floating power supply output terminal VOUT can dynamically adjust with the cathode potential of the load. It should be noted that the LED assembly of the vehicle headlight can include Da, Db, and Dc switches, or only Da, Db, or Dc, or only two of Da, Db, and Dc.

[0029] The above technical solution provides a floating power supply for the driver circuit that follows the changes in the floating ground reference terminal AGND_FLOAT, while ensuring device safety.

[0030] Further, please see Figure 1 The current mirror module 1 includes a first PMOS transistor Q1 and a second PMOS transistor Q2. The source of the second PMOS transistor Q2 is electrically connected to the first voltage source VCCA, its gate is connected to the gate of the first PMOS transistor Q1 and its own drain, and its drain is electrically connected to the source of a fourth PMOS transistor Q4. The source of the first PMOS transistor Q1 is electrically connected to the source follower module 2, and its drain is electrically connected to the source of a third PMOS transistor Q3. The gate of the fourth PMOS transistor Q4 is connected to the gate of the third PMOS transistor Q3 and its own drain, and its drain is electrically connected to the first terminal of the DC current source module 4. The drain of the third PMOS transistor Q3 is electrically connected to the source follower module 2. The fourth PMOS transistor Q4 and the third PMOS transistor Q3 are used to protect the first PMOS transistor Q1 and the second PMOS transistor Q2 when the voltage at the floating ground reference terminal AGND_FLOAT changes. The mirror ratio n of the current mirror module is determined by the size ratio of the first PMOS transistor Q1 and the second PMOS transistor Q2. The current on the branch of the first PMOS transistor Q1 is the product of the reference current Ib and the mirror ratio n.

[0031] In this design, the first PMOS transistor Q1 and the second PMOS transistor Q2 are typically ordinary voltage-rated PMOS transistors (e.g., 5V withstand voltage). The third PMOS transistor Q3 and the fourth PMOS transistor Q4 are typically high-voltage PMOS transistors, with the withstand voltage determined by the manufacturing process (e.g., 60V withstand voltage). Their function is to isolate the first PMOS transistor Q1 and the second PMOS transistor Q2 from the impact of high-voltage floating potential, ensuring the safety of the devices. The current mirror module 1 amplifies the reference current Ib provided by the DC current source module 4 by a fixed ratio n, providing a stable current input Ib×n to the first resistor R1. The branch current ratio of the first PMOS transistor Q1 to the second PMOS transistor Q2 is Ib:n*Ib. The specific design requires consideration of the size ratio of the first PMOS transistor Q1 and the second PMOS transistor Q2.

[0032] By adjusting the mirror ratio n of the current mirror module 1, the voltage value of the floating power supply output terminal VOUT can be controlled, providing a stable floating power supply for the load.

[0033] Furthermore, the source follower module 2 includes a first NMOS transistor Q7 and a second NMOS transistor Q9. The first NMOS transistor Q7 is connected in a diode configuration, with its source electrically connected to the first terminal of the first resistor R1, its gate connected to its own drain and also connected to the gate of the second NMOS transistor Q9, and its drain electrically connected to the drain of the third PMOS transistor Q3. The second NMOS transistor Q9 is connected in a source follower configuration, with its source electrically connected to the floating power supply output terminal VOUT, its drain electrically connected to the source of the first PMOS transistor Q1, and its gate electrically connected to the drain of the third PMOS transistor Q3. The source follower module 2 receives the superimposed signal of the voltage drop across the first resistor and the voltage at the floating ground reference terminal AGND_FLOAT through the first NMOS transistor Q7, and then outputs it to the floating power supply output terminal VOUT after voltage buffering by the second NMOS transistor Q9.

[0034] The source follower module 2 consists of a first NMOS transistor Q7 and a second NMOS transistor Q9, which work together to achieve a stable output of the floating power supply. The source follower module 2 first receives the superimposed voltage through Q7; specifically, see [link to relevant documentation]. Figure 1 The voltage drop across the first resistor R1, Ib×n×r1 (where Ib is the reference current, n is the current mirror ratio, and r1 is the resistance of the first resistor R1), is superimposed on the voltage at the floating ground reference terminal AGND_FLOAT. Ignoring the voltage of the high-voltage protection module 3, the voltage of VB is the voltage value Vagnd_float at the floating ground reference terminal AGND_FLOAT. The voltage at point VA satisfies VA=Vth_Q7+Ib×n×r1+Vagnd_float (Vth_Q7 is the threshold voltage of the first NMOS transistor Q7). Simultaneously, the first NMOS transistor Q7 and the second NMOS transistor Q9 are of the same type. The second NMOS transistor Q9 buffers the VA voltage in a source-follower manner, causing the voltage at the floating power supply output terminal VOUT to follow the change in VA, i.e., VOUT=VA-Vth_Q9 (Vth_Q9 is the threshold voltage of the second NMOS transistor Q9), ultimately canceling out the influence of Vth_Q7 and Vth_Q9. Therefore, the floating power supply output VOUT = Ib × n × R1 + Vagnd_float, stabilizing the floating output voltage. The first NMOS transistor Q7 and the second NMOS transistor Q9 are typically high-voltage NMOS transistors, with the voltage rating determined based on the manufacturing process.

[0035] The above technical solution provides a floating power supply for the driver circuit that follows the changes in the floating ground reference terminal AGND_FLOAT, while ensuring device safety.

[0036] Furthermore, the high-voltage protection module includes: a fifth PMOS transistor Q10, whose source is electrically connected to the floating power supply output terminal VOUT, whose drain is electrically connected to the floating ground reference terminal AGND_FLOAT, and whose gate is electrically connected between the drain of the first NMOS transistor Q7 and the gate of the second NMOS transistor Q9; a Zener diode D1, whose cathode is electrically connected to the floating power supply VOUT, and whose anode is electrically connected to the second terminal of the first resistor R1. The fifth PMOS transistor Q10 is used to drain current from the floating power supply output terminal VOUT during voltage jumps, and the Zener diode D1 is used to clamp protection when the voltage at the floating power supply output terminal VOUT rises abnormally. A sixth PMOS transistor Q8, whose source is electrically connected to the second terminal of the first resistor R1, whose gate is electrically connected to the floating ground reference terminal AGND_FLOAT, and whose drain is electrically connected to the DC current source module 4, is used to clamp the potential at the second terminal of the first resistor R1 to the potential at the floating ground reference terminal AGND_FLOAT.

[0037] In this circuit, the fifth PMOS transistor Q10 discharges excess current at the floating power supply output terminal VOUT when VOUT changes, helping to stabilize the circuit. The Zener diode D1 provides protection; when VOUT becomes abnormally high, it limits VOUT to prevent damage to subsequent circuitry. Ignoring its threshold voltage, the gate voltage of the fifth PMOS transistor Q10 is Vagnd_float. Both the fifth PMOS transistors Q10 and Q10 are typically high-voltage PMOS transistors, with the voltage rating determined by the manufacturing process.

[0038] The above technical solutions ensure device safety and guarantee stable circuit operation.

[0039] Furthermore, the DC current source module includes: a third NMOS transistor Q6, whose source is electrically connected to the negative terminal of the DC current source module 4, and whose drain is connected to the drain of the fourth PMOS transistor Q4. Its gate is connected to a fixed bias voltage VX for protecting the DC current source module. The positive terminal of the DC current source module is grounded.

[0040] The DC current source module provides the reference current Ib. The positive terminal of the DC current source module is connected to the analog ground AGND (0 potential). The fixed bias voltage VX serves as a voltage monitoring point for the internal low-voltage domain. When the low-voltage domain voltage is too high, the fixed bias voltage VX can trigger a protection mechanism to shut down the module.

[0041] Furthermore, the first resistor R1 is a variable resistor, and its resistance value can be adjusted using a decoder (e.g., a digital decoder). C1~Cn are the corresponding digital logic control signals. However, the control signals output by the array decoder are low-voltage domain signals, which cannot be directly adapted to the operating environment of the floating power supply domain in some cases. An additional level shift circuit needs to be designed to convert the low-voltage domain signals into high-level signals in the floating power supply domain, thereby regulating the output voltage of the floating power supply.

[0042] By adjusting the first resistor R1, the resistance value can be flexibly changed. It can also match the number of bits of the decoder digitizer according to actual needs, and adapt to various complex situations related to vehicle lights.

[0043] Furthermore, the voltage at the floating power supply output terminal VOUT satisfies the following relationship: VOUT = Ib * n * r1 + Vagnd_float + Vd, where Ib is the reference current, n is the mirror ratio of the current mirror module, r1 is the resistance of the first resistor, Vagnd_float is the voltage at the floating ground reference terminal, and Vd is the non-ideal voltage deviation. By compensating for the influence of the non-ideal voltage deviation on the output voltage, the voltage difference between the floating power supply output terminal VOUT and the floating ground reference terminal AGND_FLOAT is stabilized.

[0044] This circuit, applied in automotive lighting, integrates a digital processing unit and an analog-to-digital converter (ADC). The non-ideal voltage deviation Vd is primarily caused by variations in device parameters due to chip manufacturing process deviations and changes in ambient temperature. For example, ideally, the source voltage of the sixth PMOS transistor Q8 should equal the floating ground reference voltage Vagnd_float. However, in some cases, there may be a deviation in the threshold voltage Vth_Q7. This threshold voltage Vth_Q7 varies significantly with temperature and manufacturing process; this deviation is defined as the non-ideal voltage deviation Vd. Changes in the non-ideal voltage deviation Vd directly affect the voltage value of VOUT. If the non-ideal voltage deviation Vd decreases, it leads to an increase in the on-resistance of the power transistor. Under high-temperature environments and long-term operating conditions, this results in increased chip power consumption and heat generation, affecting the chip's reliability and lifespan.

[0045] Furthermore, there are two programming methods for adjusting the floating power supply output VOUT.

[0046] The first programming method involves adjusting the resistance value of a first resistor R1 via a digital decoder. The control signal from the digital decoder is converted from the low-voltage power supply domain to the floating power supply domain referenced to the floating ground reference terminal AGND_FLOAT via a level conversion circuit. By adjusting the resistance value of the first resistor R1, the voltage drop across R1 is changed, which is used to dynamically adjust the voltage at the floating power supply output terminal VOUT. This can be dynamically adjusted through programming to compensate for the influence of non-ideal voltage deviation Vd.

[0047] Please refer to the following: Figure 3 The connection method is shown in the figure. The digital decoder is connected to the first resistor R1 through a level shifting circuit, LevelShift. In this method, the resistance value of the first resistor R1 is dynamically adjusted by a digital decoder. The control signal a0 of the digital decoder is in the low-voltage power supply domain (e.g., 0~VDD, where VDD is 5V). The control signal a0 is converted from the low-voltage domain to the floating power supply domain with the floating ground reference terminal AGND_FLOAT as the reference via the level shifting circuit, LevelShift. The inverter INV (low-voltage device) can normally control the power transistor Ma, and at the same time, it works with the Zener diode D1 to achieve overvoltage protection: when the voltage difference between VOUT and AGND_FLOAT exceeds the protection threshold, the Zener diode D1 conducts in reverse to clamp the voltage.

[0048] The above technical solution provides a floating power supply for the driver circuit that follows the changes in the floating ground reference terminal AGND_FLOAT, while ensuring device safety.

[0049] It also includes a second programming method: by adjusting the magnitude of the reference current Ib generated by the DC current source module, the current flowing through the first resistor R1 is changed, which is used to change the voltage drop across the first resistor R1 and dynamically adjust the voltage at the floating power supply output terminal VOUT.

[0050] Among them, reference Figure 4 The connection method is shown in the figure. The digital decoder is connected to the DC current source module 4. In this method, the current flowing through the first resistor R1 is changed by adjusting the magnitude of the reference current Ib generated by the DC current source module 4. Since the current mirror module mirrors this current with a ratio n, the voltage drop Ib * n * R1 on R1 changes accordingly, thereby achieving dynamic adjustment of the entire output voltage VOUT.

[0051] This programming method eliminates the need for a level shift circuit, allowing all control circuits to operate in the low-voltage domain. It provides the driver circuit with a floating power supply that follows the changes in the floating ground reference terminal AGND_FLOAT, while ensuring device safety.

[0052] The above describes the floating power generation circuit for driving circuits provided in the embodiments of this application. An embodiment of this application also provides an integrated circuit chip including the above-described floating power generation circuit for driving circuits.

[0053] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A floating power supply generating circuit for a drive circuit, characterized in that: It includes a current mirror module, a source follower module, a DC current source module, a first resistor, a floating ground reference terminal, a floating power supply output terminal, and a high voltage protection module; The first end of the current mirror module is electrically connected to the first voltage source, the second end is electrically connected to the source follower module, and the third end is electrically connected to the first end of the DC current source module. The current mirror module is used to receive and mirror the reference current, so that the mirrored current flows through the first resistor and generates a voltage drop. The second terminal of the DC current source module is electrically connected to the first terminal of the high voltage protection module to provide the reference current; The first resistor is electrically connected between the source follower module and the high voltage protection module; The second terminal of the source follower module is electrically connected to the first terminal of the first resistor, and is used to perform voltage buffering and output after superimposing the voltage drop across the first resistor and the voltage of the floating ground reference terminal. The third terminal of the source follower module is electrically connected to the floating power supply output terminal and the high voltage protection module, respectively. The second terminal of the high-voltage protection module is electrically connected to the second terminal of the first resistor, and the third and fourth terminals are electrically connected to the floating ground reference terminal and the floating power supply output terminal, respectively, for leakage and overvoltage protection. The floating ground reference terminal is connected to the load, and the floating power output terminal changes with the floating ground reference terminal. At least one of the following can be adjusted: the resistance value of the first resistor, the reference current, and the mirror ratio of the current mirror module, to adjust the voltage of the floating power output terminal. The floating power output terminal supplies floating power to the load.

2. The floating power supply generating circuit for a driving circuit according to claim 1, characterized in that: The current mirror module includes a first PMOS transistor and a second PMOS transistor. The source of the second PMOS transistor is electrically connected to the first voltage source, its gate is connected to the gate of the first PMOS transistor and its own drain, and its drain is electrically connected to the source of a fourth PMOS transistor. The source of the first PMOS transistor is electrically connected to the source follower module, and its drain is electrically connected to the source of a third PMOS transistor. The gate of the fourth PMOS transistor is connected to the gate of the third PMOS transistor and its own drain, and its drain is electrically connected to the first terminal of the DC current source module. The drain of the third PMOS transistor is electrically connected to the source follower module. The fourth and third PMOS transistors are used to protect the first and second PMOS transistors when the voltage at the floating ground reference terminal changes. The mirror ratio of the current mirror module is determined by the size ratio of the first PMOS transistor and the second PMOS transistor, and the current in the branch of the first PMOS transistor is the product of the reference current and the mirror ratio.

3. The floating power supply generating circuit for a driving circuit according to claim 2, characterized in that: The source follower module includes a first NMOS transistor and a second NMOS transistor. The first NMOS transistor is connected in a diode configuration, with its source electrically connected to the first terminal of a first resistor, its gate connected to its own drain and electrically connected to the gate of the second NMOS transistor, and its drain electrically connected to the drain of the third PMOS transistor. The second NMOS transistor is connected in a source follower configuration, with its source electrically connected to the floating power supply output terminal, its drain electrically connected to the source of the first PMOS transistor, and its gate electrically connected to the drain of the third PMOS transistor. The source follower module receives the superimposed signal of the voltage drop across the first resistor and the voltage at the floating ground reference terminal through the first NMOS transistor, and then outputs it to the floating power supply output terminal after voltage buffering by the second NMOS transistor.

4. The floating power supply generating circuit for a drive circuit according to claim 3, characterized in that: The high-voltage protection module includes: The fifth PMOS transistor has its source electrically connected to the floating power supply output terminal, its drain electrically connected to the floating ground reference terminal, and its gate electrically connected between the drain of the first NMOS transistor and the gate of the second NMOS transistor; the Zener diode has its cathode electrically connected to the floating power supply output terminal and its anode electrically connected to the second terminal of the first resistor; the fifth PMOS transistor is used to drain current from the floating power supply output terminal during voltage jumps, and the Zener diode is used to clamp and protect the floating power supply output terminal when the voltage rises abnormally.

5. The floating power supply generating circuit for a drive circuit according to claim 4, characterized in that: The high-voltage protection module also includes: The sixth PMOS transistor has its source electrically connected to the second terminal of the first resistor, its gate electrically connected to the floating ground reference terminal, and its drain electrically connected to the DC current source module, for clamping the potential of the second terminal of the first resistor to the potential of the floating ground reference terminal.

6. The floating power supply generating circuit for a drive circuit according to claim 5, characterized in that: The DC current source module includes: The third NMOS transistor has its source electrically connected to the negative terminal of the DC current source module, its drain connected to the drain of the fourth PMOS transistor, and its gate connected to a fixed bias voltage to protect the DC current source module; the positive terminal of the DC current source module is grounded.

7. The floating power supply generating circuit for a driving circuit according to claim 6, characterized in that: The first resistor is a variable resistor.

8. The floating power supply generating circuit for a driving circuit according to claim 1, characterized in that: The voltage at the output terminal of the floating power supply satisfies the following relationship: VOUT = Ib * n * r1 + Vagnd_float + Vd, where Ib is the reference current, n is the mirror ratio of the current mirror module, r1 is the resistance value of the first resistor, Vagnd_float is the voltage at the floating ground reference terminal, and Vd is the non-ideal voltage deviation. By compensating for the influence of the non-ideal voltage deviation on the output voltage, the voltage difference between the output terminal of the floating power supply and the floating ground reference terminal is stabilized.

9. The floating power supply generating circuit for a driving circuit according to claim 8, characterized in that, The methods for adjusting the output of the floating power supply include a first programming method: The resistance value of the first resistor is adjusted by a digital decoder. The control signal of the digital decoder is converted from the low-voltage power domain to the floating power domain with the floating ground reference terminal as the reference via a level conversion circuit. By adjusting the resistance value of the first resistor, the voltage drop across the first resistor is changed, which is used to dynamically adjust the voltage at the output terminal of the floating power supply.

10. The floating power supply generating circuit for a drive circuit according to claim 8, characterized in that, The method for adjusting the output of the floating power supply includes a second programming method: By adjusting the magnitude of the reference current generated by the DC current source module, the current flowing through the first resistor is changed, thereby changing the voltage drop across the first resistor and dynamically adjusting the voltage at the output terminal of the floating power supply.

11. An integrated circuit chip, characterized in that, include: The floating power supply generating circuit for driving circuits according to any one of claims 1-10.

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