Brake power supply chip and power-on method thereof

Abstract

This invention provides a braking power supply chip and its power-on method, integrating at least a primary buck module, a secondary buck module, and a core voltage regulator module. The primary buck module boosts the external power supply voltage, while the secondary buck module and the core voltage regulator module both step down the external power supply voltage. This allows all three modules to output drive voltages to the gates of their internal power transistors. Therefore, a charge pump is not required to drive the gates of the internal power transistors in the primary and secondary buck modules, as well as the external power transistor in the core voltage regulator module. This not only directly utilizes a 48V power supply voltage but also optimizes the chip area. Furthermore, the primary, secondary, and core voltage regulator modules drive their respective internal power transistor gates through independent boost and buck structures, avoiding common-cause failure problems caused by using the same boost structure.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and in particular to a braking power supply chip and its power-on method. Background Technology

[0002] Currently, chassis systems, including braking, steering, and suspension systems, all require high-functional-safety-level PMIC chips to power the MCU. Most systems are still 12V, with a few starting to use 48V. Existing 48V solutions typically step down the 48V voltage to 12V before supplying power to the 12V system.

[0003] However, existing 48V systems require a pre-voltage step-down chip to reduce the 48V voltage before inputting a 12V power supply to the 12V braking power chip. Therefore, there is currently no solution for a braking power chip that directly utilizes 48V power. Furthermore, existing 12V braking power chips require a single charge pump to boost the input 12V for driving the gates of the power transistors within each power module, leading to a common-cause failure problem due to the use of a single charge pump. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a braking power supply chip and its power-on method, thereby resolving the common-cause failure problem of the power supply in the chip by directly applying a 48V power supply voltage.

[0005] According to a first aspect of the present invention, a braking power supply chip is provided, the chip comprising: A first-stage buck module is used to perform a first step-down on the external power supply voltage and output a first step-down voltage; it is also used to perform a first step-up on the external power supply voltage and output a first drive voltage to the gate of its internal power transistor, wherein the difference between the first drive voltage and the external power supply voltage is greater than or equal to the threshold voltage of the power transistor in the first-stage buck module; the external power supply voltage is greater than or equal to 48V; The secondary step-down module is used to perform a second step-down on the first step-down voltage and output the second step-down voltage; it is also used to perform a third step-down on the external power supply voltage and output a second drive voltage to the gate of its internal power transistor, wherein the difference between the second drive voltage and the first step-down voltage is greater than or equal to the threshold voltage of the power transistor in the secondary step-down module. The core voltage regulator module is used to convert the second step-down voltage into a linear step-down supply voltage or a switching step-down supply voltage according to the mode selection signal; it is also used to perform a fourth step-down on the external power supply voltage and output a third drive voltage to the gate of the external power transistor, wherein the difference between the third drive voltage and the second step-down voltage is greater than or equal to the threshold voltage of the power transistor in the core voltage regulator module. The primary step-down module, the secondary step-down module, and the core voltage regulator module are all integrated into a single chip.

[0006] Optionally, a first linear regulator module is also integrated to perform first linear regulation on the second step-down voltage and output a first supply voltage, which is used to power the first I / O interface of the MCU or the first CAN interface of the system. The second linear regulator module is used to perform second linear regulation on the second step-down voltage and output a second power supply voltage, which is used to power the second I / O interface of the MCU or the second CAN interface of the system. The third linear regulator module is used to perform third linear regulation on the second step-down voltage and output a third power supply voltage, which is used to power the analog-to-digital converter in the MCU.

[0007] Optionally, the second step-down voltage is 6.5V or 7.2V, the corresponding output current is 1.4A, and the operating frequency of the second step-down module is 465KHz; The first power supply voltage is 5V, the accuracy of the first power supply voltage is ±2%, and the output current corresponding to the first power supply voltage is 250mA; The second power supply voltage is 3.3V or 5.0V, the accuracy of the second power supply voltage is ±2%, and the output current corresponding to the second power supply voltage is 250mA; The third power supply voltage is 5.0V, the accuracy of the third power supply voltage is ±1%, and the output current corresponding to the third power supply voltage is 100mA; Both the linear step-down power supply voltage and the switching step-down power supply voltage are between 0.8V and 5.0V. The output current corresponding to the linear step-down power supply voltage is 0.8A, and the output current corresponding to the switching step-down power supply voltage is 1.5A.

[0008] Optionally, a voltage monitoring module is also integrated. The voltage monitoring module is used to detect the first step-down voltage, the second step-down voltage, the first supply voltage, the second supply voltage, the third supply voltage, the switching step-down supply voltage, and the linear step-down supply voltage, and output corresponding fault signals according to the faults detected in each voltage. The fault signals represent the undervoltage or overvoltage of the first step-down voltage, the second step-down voltage, the first supply voltage, the second supply voltage, the third supply voltage, the switching step-down supply voltage, and the linear step-down supply voltage, respectively.

[0009] Optionally, a logic control module is also integrated, which is used to transmit the fault signal output by the voltage monitoring module to the MCU so that the MCU can determine the specific fault of the corresponding module. It also integrates a safety status output module, which is used to transmit the specific fault of the corresponding module to the braking actuator outside the chip when the MCU determines the specific fault of the corresponding module, and output a system shutdown signal to shut down the braking actuator.

[0010] Optionally, the logic control module is further configured to directly output a first shutdown drive signal based on the fault signal output by the voltage monitoring module; It also integrates a safety shutdown module, which cuts off the power input of the first-stage buck module according to the first shutdown drive signal.

[0011] Optionally, the first-stage buck module includes a first withstand voltage NMOS transistor, a second withstand voltage NMOS transistor, and a first low-side NMOS transistor. The drain of the first withstand voltage NMOS transistor is connected to the external power supply voltage, and the source of the first withstand voltage NMOS transistor is connected to the drain of the second withstand voltage NMOS transistor. The first withstand voltage NMOS transistor is turned off according to the first turn-off drive signal connected to its gate. The source of the second withstand voltage NMOS transistor is connected to the drain of the first low-side NMOS transistor. The source of the first low-side NMOS transistor is connected to ground. The withstand voltage of the first withstand voltage NMOS transistor, the second withstand voltage NMOS transistor, and the low-side NMOS transistor is all greater than or equal to 80V.

[0012] Optionally, an analog-to-digital conversion module is also integrated, which is used for: The first supply voltage, the second supply voltage, the third supply voltage, the switching buck supply voltage, and the linear buck supply voltage are all converted from analog to digital into corresponding digital signals and output to the MCU. The externally input voltage signal is converted from analog to digital and then output to the logic control module. The external input mode selection signal is transmitted to the core voltage regulator module; It also integrates a wheel speed sensor power supply module, which is used to convert the wheel speed signal output by the external wheel speed sensor into a digital signal and output it to the MCU. The wheel speed sensor power supply module is also used to power the wheel speed sensor.

[0013] A second aspect of the present invention provides a power-on method for a braking power supply chip, based on the braking power supply chip described in the first aspect and optional embodiments of the present invention, the power-on method comprising: The internal power supply module of the braking power chip supplies power to each module within the chip after receiving an external wake-up signal and an external power supply. After being powered by the external input power supply and the internal power supply module, the first-stage buck module outputs a first buck voltage to the second-stage buck module; After the first step-down voltage is input, the secondary step-down module outputs the second step-down voltage to the core voltage regulator module; After the core voltage regulator module is input with the second step-down voltage, it outputs a linear step-down power supply voltage or a switching step-down power supply voltage to the MCU according to the mode selection signal, so as to power the core of the MCU. After the second step-down voltage is input to the first, second, and third linear voltage regulator modules, the first, second, and third supply voltages are output respectively to supply power to the MCU's I / O interface, the system's CAN interface, and the MCU's ADC.

[0014] Optionally, the power-on process of the chip may also include: The logic control module outputs a first fault injection signal to the core voltage regulator module, the first-stage buck module, the second-stage buck module, the first linear voltage regulator module, the second linear voltage regulator module, and the third linear voltage regulator module; After the core voltage regulator module supplies power to the core of the MCU, it also includes: feeding back the detection structure corresponding to the first fault injection signal to the MCU.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The braking power supply chip provided by this invention integrates at least a first-stage buck module, a second-stage buck module, and a core voltage regulator module. The first-stage buck module boosts the external power supply voltage and outputs a first driving voltage to the gate of its internal power transistor; the second-stage buck module bucks the external power supply voltage a third time and outputs a second driving voltage to the gate of its internal power transistor; the core voltage regulator module bucks the external power supply voltage a fourth time and outputs a third driving voltage to the gate of the external power transistor. Since the difference between the first driving voltage and the external power supply voltage is greater than or equal to the threshold voltage of the power transistor in the first-stage buck module; the difference between the second driving voltage and the first buck voltage is greater than or equal to the threshold voltage of the power transistor in the second-stage buck module; and the difference between the third driving voltage and the second buck voltage is greater than or equal to the threshold voltage of the power transistor in the core voltage regulator module, this invention can achieve gate driving of the power transistors in the first-stage buck module, the second-stage buck module, and the core voltage regulator module without the need for an additional charge pump to boost the external power supply voltage, the first buck voltage, and the second buck voltage. This not only directly utilizes an external power supply voltage of 48V or higher but also optimizes the chip area.

[0016] In addition, the primary buck module, the secondary buck module, and the core voltage regulator module each drive the gate of their internal power transistors through their own independent boost and buck structures, avoiding common-cause failures caused by using the same boost structure and improving the chip's safety.

[0017] In summary, the braking power supply chip provided by this invention, based on the direct application of an external power supply voltage of 48V or higher, not only optimizes the chip area but also reduces common-cause failures between the power supply and drive circuit, thereby improving the chip's safety.

[0018] Furthermore, this invention sets the output current corresponding to the second buck voltage to 1.4A, the output current corresponding to the linear buck supply voltage to 0.8A, and the output current corresponding to the switching buck supply voltage to 1.5A, thereby improving the output power of the second buck module and the core voltage regulator module to meet the power supply requirements of the MCU in a 48V system. In addition, this invention sets the accuracy of the first supply voltage and the second supply voltage to ±2%, and the accuracy of the third supply voltage to ±1%, thereby improving the accuracy of power supply to the MCU's analog-to-digital converter and I / O interface.

[0019] Furthermore, the braking power chip also integrates a safety shutdown module. The logic control module directly outputs a first shutdown drive signal to the safety shutdown module based on the fault signal output by the voltage monitoring module. The safety shutdown module cuts off the power input of the first-stage buck module based on the first shutdown drive signal, thereby achieving shutdown redundancy and further improving the safety of the system using the braking power chip.

[0020] Furthermore, a first and a second withstand voltage NMOS transistor are connected in series within the first-stage buck module. This ensures that if a single withstand voltage NMOS transistor fails, the external power supply voltage will not be transmitted to the second buck module, all linear regulator modules, the core regulator module, and loads such as the MCU and CAN interface, thereby further improving the chip's safety.

[0021] Furthermore, when the first linear regulator module to the third linear regulator module or the core regulator module fails and cannot be turned off, the safety shutdown module outputs a first shutdown drive signal to the gate of the first withstand voltage NMOS transistor to turn off the first withstand voltage NMOS transistor, thereby cutting off the power input of the first-stage buck module, and further cutting off the power input of the first linear regulator module to the third linear regulator module and the core regulator module.

[0022] Furthermore, by integrating an analog-to-digital conversion module, the MCU can read the values ​​of the first power supply voltage, the second power supply voltage, the third power supply voltage, the switching buck power supply voltage, and the linear buck power supply voltage, thereby taking corresponding measures based on the actual magnitude of each voltage, thus further improving the chip's security.

[0023] Furthermore, the braking power chip also integrates a safety status output module, which is used to transmit the specific fault of the corresponding module to the braking actuator outside the chip when the MCU determines the specific fault of the corresponding module, and output a system shutdown signal to shut down the braking actuator, thereby improving the safety of the system using the braking power chip.

[0024] The power-on method for the braking power supply chip provided by this invention first wakes up the internal power supply module within the chip to supply power to the various modules within the chip. Then, the first-stage buck module, the second-stage buck module, and the core voltage regulator module are powered on sequentially, so that the core voltage regulator module outputs a linear buck supply voltage or a switching buck supply voltage to the MCU according to the mode selection signal to power the core of the MCU, thereby ensuring the power-on safety of the chip.

[0025] Furthermore, after the core voltage regulator module supplies power to the core of the MCU, the logic control module outputs a first fault injection signal to the core voltage regulator module to inject a fault into the core voltage regulator module and feeds back the detection result to the MCU, thereby realizing the self-diagnosis of fault detection, that is, whether the fault diagnosis function of the detection chip is normal. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the circuit structure of the electronic braking chip provided in this embodiment; Figure 2 A schematic diagram of the circuit structure of the first-stage step-down module provided in this embodiment; Figure 3 This is a flowchart of the power-on method for the electronic braking chip provided in this embodiment. Attached image description: 101-Level 1 step-down module; 102-Two-stage step-down module; 103 - First linear voltage regulator module; 104 - Second linear regulator module; 105 - Third linear voltage regulator module; 106 - Core voltage regulator module; 110 - Voltage monitoring module; 111 - Logic Control Module; 114 - Safety Shutdown Module; 115 - Analog-to-Digital Conversion Module; 116 - Wheel speed sensor power supply module; 117 - Voltage Tracking Module; 118 - Internal power supply module; 1181 - Internal analog power supply unit; 1182 - Internal digital power supply unit; 1183 - First Reference Source; 1184 - Second Reference Source; 119 - Watchdog module; 120 - Safety Status Output Module; VBAT - External power supply voltage; V0 - First step-down voltage; V1 - Second step-down voltage; V2 - First power supply voltage; V3 - Second power supply voltage; V4 - Third power supply voltage; V5 - Linear buck supply voltage or switching buck supply voltage; V6 - Voltage divider feedback voltage; Ve5 - First shutdown drive signal; Vf1 - System shutdown signal; SW1 - First switching switch; M1 - First withstand voltage NMOS transistor; M2 - Second withstand voltage NMOS transistor; M3 - Low-side NMOS transistor; fsn1 - First state output pin; fsn2 - Second state output pin. Detailed Implementation

[0029] As described in the background section, existing 48V systems require a pre-amplifier to step down the 48V voltage before inputting a 12V power supply to the 12V braking power chip. Therefore, there is currently no solution for a braking power chip that directly utilizes a 48V power supply. Furthermore, existing 12V braking power chips require a single charge pump to boost the input 12V for driving the gates of the power transistors within each power module, leading to a common-cause failure problem due to the use of a single charge pump.

[0030] In view of this, the technical solution of the present invention provides a new braking power supply chip, which integrates at least the first-stage buck module, the second-stage buck module and the core voltage regulator module. On the basis of directly applying an external power supply voltage of 48V or above, it not only optimizes the chip area, but also reduces common-cause failures between the power supply and the drive circuit, thereby improving the safety of the chip.

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0034] Figure 1 This is a schematic diagram of the module structure of the braking power supply chip provided in the first embodiment.

[0035] Please refer to Figure 1 This embodiment provides a braking power supply chip, which integrates at least the first-stage step-down module 101, the second-stage step-down module 102, the first linear voltage regulator module 103, the second linear voltage regulator module 104, the third linear voltage regulator module, and the core voltage regulator module 106.

[0036] The first-stage step-down module 101 is used to step down the external power supply voltage VBAT and output the first step-down voltage V0.

[0037] The first-stage buck module 101 is also used to boost the external power supply voltage VBAT and output a first drive voltage to the gate of its internal power transistor. The difference between the first drive voltage and the external power supply voltage VBAT is greater than or equal to the threshold voltage of the power transistor in the first-stage buck module 101, so as to ensure that the power transistor in the first-stage buck module 101 can be turned on normally.

[0038] Because 48V systems offer cost advantages such as lower power loss, higher output efficiency, and lighter system wiring harnesses, as well as helping to reduce the weight of the entire vehicle, and because 48V is far below the 60V limit for preventing electric shock hazards, and because the maximum charging voltage of a 48V battery is 56V, which is the highest voltage level under safe voltage conditions, the external power supply voltage VBAT is 48V in this embodiment.

[0039] In this embodiment, after the first step-down, the first step-down voltage V0 can be between 12V and 13.5V. After the first step-up, the first drive voltage can be between 50V and 52V.

[0040] Please refer to Figure 2 In this embodiment, the first-stage buck module 101 includes a first-voltage NMOS transistor M1, a second-voltage NMOS transistor M2, and a first low-side NMOS transistor M3. The drain of the first-voltage NMOS transistor M1 is connected to the external power supply voltage VBAT, and the source of the first-voltage NMOS transistor M1 is connected to the drain of the second-voltage NMOS transistor M2. The first-voltage NMOS transistor M1 is turned off according to the first turn-off drive signal Ve5 connected to its gate. The source of the second-voltage NMOS transistor M2 is connected to the drain of the first low-side NMOS transistor M3. The source of the first low-side NMOS transistor M3 is connected to ground. Further, the withstand voltage of both the first-voltage NMOS transistor M1 and the second-voltage NMOS transistor M2 is greater than or equal to 80V. The withstand voltage of the first low-side NMOS transistor M3 is also greater than or equal to 80V.

[0041] By setting up a first withstand voltage NMOS transistor M1 and a second withstand voltage NMOS transistor M2 connected in series, the external power supply voltage VBAT will not be transmitted to the devices in the second-stage buck module when a single withstand voltage NMOS transistor fails. This can be understood as setting up double protection to prevent the devices in the second-stage buck module from being damaged by the external power supply voltage VBAT when a single withstand voltage NMOS transistor fails, which could then lead to the breakdown of all linear regulator modules and the core regulator module, ultimately burning out the chip and MCU, thereby improving the chip's safety.

[0042] The secondary buck module 102 is used to perform a second buck reduction on the first buck voltage V0 and output a second buck voltage V1. The secondary buck module 102 is also used to perform a third buck reduction on the external power supply voltage VBAT and output a second drive voltage to the gate of its internal power transistor to drive the internal power transistor. The difference between the second drive voltage and the first buck voltage V0 is greater than or equal to the threshold voltage of the power transistor within the secondary buck module 102.

[0043] In this embodiment, the second step-down voltage V1 can be 6.5V or 7.2V, the corresponding output current of the second step-down voltage V1 can be 1.4A, and the operating frequency of the second step-down module can be 465KHz. The second drive voltage can be greater than 12V.

[0044] The first linear regulator module 103 is used to perform first linear regulation on the second step-down voltage V1 and output a first power supply voltage V2. The first power supply voltage V2 is used to power the first I / O interface of the MCU or the first CAN interface of the system.

[0045] In this embodiment, the first power supply voltage V2 can be 5V, the accuracy of the first power supply voltage V2 can be ±2%, and the output current corresponding to the first power supply voltage V2 can be 250mA.

[0046] The second linear regulator module 104 is used to perform second linear regulation on the second step-down voltage V1 and output a second power supply voltage V3. The second power supply voltage V3 is used to power the second I / O interface of the MCU or the second CAN interface of the system.

[0047] In this embodiment, the second power supply voltage can be 3.3V or 5.0V, the accuracy of the second power supply voltage can be ±2%, and the output current corresponding to the second power supply voltage can be 250mA.

[0048] The third linear regulator module 105 is used to perform third linear regulation on the second step-down voltage V1 and output a third power supply voltage V4, which is used to power the analog-to-digital converter in the MCU.

[0049] In this embodiment, the third power supply voltage V4 can be 5.0V, the accuracy of the third power supply voltage V4 can be ±1%, and the output current corresponding to the third power supply voltage V4 can be 100mA.

[0050] The core voltage regulator module 106 is used to convert the second buck voltage V1 into a linear buck supply voltage or a switching buck supply voltage V5 according to the mode selection signal, so as to power the processing core of the MCU. The core voltage regulator module 106 is also used to perform a fourth buck operation on the external power supply voltage VBAT and output a third drive voltage to the gate of the external power transistor to drive its own internal power transistor. The difference between the third drive voltage and the second buck voltage V1 is greater than or equal to the threshold voltage of the power transistor inside the core voltage regulator module 106. Further, the third drive voltage can be set to be greater than 12V.

[0051] It can be understood that the core voltage regulator module 106 enters the switching buck output mode or the linear buck output mode according to the mode selection signal, and outputs the buck supply voltage V5. Both the switching buck supply voltage and the linear buck supply voltage are used to supply power to the working core of the MCU.

[0052] In this embodiment, both the linear buck supply voltage and the switching buck supply voltage V5 can be between 0.8V and 5.0V. The output current corresponding to the linear buck supply voltage V5 can be 0.8A, and the output current corresponding to the switching buck supply voltage V5 can be 1.5A.

[0053] In this embodiment, the output current corresponding to the second buck voltage V1 is set to 1.4A, the output current corresponding to the linear buck supply voltage V5 is set to 0.8A, and the output current corresponding to the switching buck supply voltage V5 is set to 1.5A. This improves the output power of the second buck module and the core voltage regulator module 106 to meet the power supply requirements of the MCU in a 48V system. Furthermore, the present invention sets the accuracy of the first supply voltage V2 and the second supply voltage to ±2%, and the accuracy of the third supply voltage V4 to ±1%, thereby improving the accuracy of power supply to the MCU's analog-to-digital converter and I / O interface.

[0054] Since the first buck module in this embodiment directly boosts the external power supply voltage VBAT to drive its internal power transistors, and the second buck module 102 and the core voltage regulator module 106 both directly buck the external power supply voltage VBAT to drive their own power transistors, there is no need to set up an additional charge pump to boost the external power supply voltage VBAT, the first buck voltage V0, and the second buck voltage V1 to achieve gate driving of the internal power transistors of the first buck module 101, the second buck module 102, and the core voltage regulator module 106. This saves the area of ​​the integrated charge pump and thus optimizes the chip area.

[0055] It should be added that, in order to filter the first step-down voltage V0, the second step-down voltage V1, the first power supply voltage V2, the second power supply voltage V3, the third power supply voltage V4, and the switching / linear step-down power supply voltage V5, and to output different voltages according to the different modes of the core voltage regulator module 106, and in order to reduce the chip area, corresponding filtering structures and corresponding mode switching structures are also set on the periphery of the braking power supply chip for each module that supplies power to the MCU.

[0056] Specifically, outside the chip, the secondary buck unit 102 corresponds to a clamping diode D1, a first filter inductor L1, and a first filter capacitor C1. The cathode of the clamping diode D1 and one end of the first filter inductor L1 are connected to the output terminal of the secondary buck unit 102. The other end of the first filter inductor L1 and one end of the first filter capacitor C1 are connected to the second buck voltage V1 output pin of the electronic braking chip, and output the second buck voltage V1. The anode of the clamping diode D1 and the other end of the first filter capacitor C1 are both connected to ground.

[0057] The first linear regulator module 103, the second linear regulator module 104, and the third linear regulator module 105 correspond to the second filter capacitor C2, the third filter capacitor C3, the fourth filter capacitor C4, and the fifth filter capacitor C5, respectively. One end of the second filter capacitor C2 is connected to one end of the first filter capacitor C1 and the second step-down voltage V1 input pin of the braking power supply chip. The second step-down voltage V1 input pin is connected to the input terminals of the first linear regulator module 103, the second linear regulator module 104, and the third linear regulator module 105, respectively, to input the filtered second step-down voltage V1 to the first linear regulator module 103, the second linear regulator module 104, and the third linear regulator module 105. One end of the third filter capacitor C3 is connected to the first power supply voltage V2 pin of the braking power supply chip, and the first power supply voltage V2 pin is connected to the output terminal of the first linear regulator module 103, outputting the first power supply voltage V2. One end of the fourth filter capacitor C4 is connected to the third power supply voltage V3 pin of the braking power chip. The second power supply voltage V3 pin is connected to the output terminal of the second linear regulator module 104, and outputs the second power supply voltage V3. One end of the fifth filter capacitor C5 is connected to the fourth power supply voltage V4 pin of the braking power chip. The third power supply voltage V4 pin is connected to the output terminal of the third linear regulator module 105, and outputs either the third power supply voltage V4 or the fifth power supply voltage V5. The other ends of the second filter capacitor C2, the third filter capacitor C3, the fourth filter capacitor C4, and the fifth filter capacitor C5 are all connected to ground.

[0058] The core voltage regulator module 106 corresponds to the sixth filter capacitor C6, the seventh filter capacitor C7, the first filter resistor R1, the second filter resistor R2, the second filter inductor L2, the power transistor M1, the first voltage divider resistor R3, and the second voltage divider resistor R4. One end of the first filter resistor R1 is connected to the other end of the first filter capacitor C1 and the first current input pin of the braking power chip, which is connected to the core voltage regulator module 106. The other end of the first filter resistor R1 is connected to the second current input pin of the braking power chip and the drain of the power transistor M1, which is connected to the core voltage regulator module 106. The gate of the power transistor M1 is connected to one end of the second filter resistor R2, and the source of the power transistor M1 is connected to the source output pin of the braking power chip, one end of the second filter inductor L2, and ground, which is connected to the core voltage regulator module 106. The other end of the second filter inductor L2 is connected to one end of the first voltage divider resistor R3, one end of the seventh filter capacitor C7, and the feedback pin of the linear buck supply voltage V5, and outputs the linear buck supply voltage V5. The feedback pin of the linear buck supply voltage V5 is used to feed the linear buck supply voltage V5 back to the core voltage regulator module 106 to achieve negative feedback balance of the linear buck supply voltage V5. One end of the sixth filter capacitor C6 is connected to the core voltage regulator module 106 through one end of the braking power chip, and the other end of the sixth filter capacitor C6 is connected to the source of M1. The other end of the seventh filter capacitor C7 is connected to ground. The other end of the first voltage divider resistor R3 is connected to one end of the second voltage divider resistor R4 and the feedback pin of the voltage divider feedback voltage V6 of the braking power chip, and outputs the voltage divider feedback voltage V6. The feedback pin of the voltage divider feedback voltage V6 is used to feed the voltage divider feedback voltage V6 back to the core voltage regulator module 106 to achieve negative feedback balance of the voltage divider feedback voltage V6. Furthermore, when the core voltage regulator module 106 outputs the switching / linear buck supply voltage V5, the core voltage regulator module 106 controls the power transistor M1 to turn on and off. The above describes the specific details of the first-stage step-down module 101, the second-stage step-down module 102, the first linear regulator module 103, the second linear regulator module 104, the third linear regulator module 105, and the core regulator module 106 in this embodiment. The remaining modules in this embodiment will be described in detail below.

[0059] Please continue to refer to this. Figure 1In this embodiment, the braking power supply chip also integrates a voltage monitoring module 110. The voltage monitoring module 110 is used to detect the first step-down voltage V0, the second step-down voltage V1, the first supply voltage V2, the second supply voltage, the third supply voltage V4, the voltage divider feedback voltage V6, and the switching / linear step-down supply voltage V5, and output corresponding fault signals according to the faults detected in each voltage. The fault signals represent the undervoltage or overvoltage of the first step-down voltage V0, the second step-down voltage V1, the first supply voltage V2, the second supply voltage V3, the third supply voltage V4, the voltage divider feedback voltage V6, and the switching / linear step-down supply voltage V5.

[0060] Please continue to refer to this. Figure 1 The braking power supply chip in this embodiment also integrates a logic control module 111. The logic control module 111 is used to transmit the fault signal output by the voltage monitoring module 110 to the MCU, so that the MCU can determine the specific fault of the corresponding module. For example, the fault may be a short circuit to the power supply, a short circuit to ground, or an overcurrent in the internal drive power transistor of the core voltage regulator module 106, which is defined by the corresponding module type and fault type.

[0061] In this embodiment, the MCU obtains the fault signal output by the voltage monitoring module 110 through the SPI communication interface within the chip.

[0062] Please continue to refer to this. Figure 1 In this embodiment, the braking power chip also integrates a safety status output module 120. The safety status output module 120 is used to transmit the specific fault of the corresponding module to the braking actuator outside the chip when the MCU determines the specific fault of the corresponding module, so as to notify the braking actuator outside the chip whether the braking power chip is in a safe state, and to shut down the braking actuator by outputting a system shutdown signal Vf1, thereby improving the safety of the system using the braking power chip.

[0063] In this embodiment, the braking power chip is provided with a first state output pin fsn1 and a second state output pin fsn2. The safety state output module 120 transmits digital signals representing specific faults of the corresponding module to the braking actuator outside the chip through the first state output pin fsn1 and the second state output pin fsn2 to notify the braking actuator outside the chip whether the braking power chip is in a safe state, and outputs a system shutdown signal Vf1 to the outside through the first state output pin fsn1 and the second state output pin fsn2.

[0064] Please continue to refer to this. Figure 1The braking power chip also integrates a watchdog module 119, which is used to monitor the logic function of the MCU and the communication status between the chip and the MCU, and outputs an MCU fault signal to the MCU according to the detected fault.

[0065] Please continue to refer to this. Figure 1 The braking power chip in this embodiment also integrates a safety shutdown module 114.

[0066] When the MOSFETs in the first-stage buck module 101, second-stage buck module 102, first linear regulator module 103, second linear regulator module 104, third linear regulator module 105, and core regulator module 106 experience short circuits or other faults and cannot be shut down, the logic control module 111 will directly output a first shutdown drive signal Ve5 to the safety shutdown module 114 based on the fault signal output by the voltage monitoring module 110. The safety shutdown module 114 will directly shut down the first withstand voltage NMOS transistor M1 based on the first shutdown drive signal Ve5, thereby cutting off the external power supply voltage VBAT input to the first-stage buck module 101. Since the first-stage buck module 101 steps down the external input voltage to output a first-stage buck voltage V0, this becomes the power supply voltage for the subsequent second-stage buck module 102. The second step-down module 102 outputs a second step-down voltage V1 from the first step-down voltage V0, which is the power supply voltage for the subsequent first linear regulator module 103, second linear regulator module 104, third linear regulator module 105, and core regulator module 106. Therefore, after disconnecting the external power supply voltage VBAT from the first step-down module 101, the second step-down module 102, first linear regulator module 103, second linear regulator module 104, third linear regulator module 105, and core regulator module 106 all stop working.

[0067] The safety redundancy of shutdown is achieved through the safety shutdown module 114, thereby further improving the safety of the system using the braking power supply chip.

[0068] In addition, this embodiment uses the first withstand voltage NMOS transistor M1 to isolate power supply faults, thus preventing a single fault from causing a complete system failure.

[0069] Please continue to refer to this. Figure 1In this embodiment, the braking power supply chip also integrates an analog-to-digital converter module 115. The analog-to-digital converter module 115 is used to convert the first power supply voltage V2, the second power supply voltage V3, the third power supply voltage V4, the voltage divider feedback voltage V6, and the switching / linear buck power supply voltage V5 into corresponding digital signals and output them to the MCU. This enables the MCU to read the values ​​of the first power supply voltage V2, the second power supply voltage V3, the third power supply voltage V4, the voltage divider feedback voltage V6, and the switching / linear buck power supply voltage V5, and thus take corresponding measures based on the actual magnitude of each voltage, thereby further improving the safety of the chip.

[0070] The analog-to-digital conversion module 115 is also used to convert the externally input voltage signal into a corresponding digital signal and output it to the logic control module 111 to monitor the peripheral circuit of the chip.

[0071] The analog-to-digital converter module 115 is also used to transmit the externally input mode selection signal to the core voltage regulator module 106 so that the core voltage regulator module 106 selects the corresponding output mode.

[0072] In this embodiment, when the externally input mode selection signal is high, the core voltage regulator module 106 enters the linear buck output mode. When the externally input mode selection signal is low, the core voltage regulator module 106 enters the switching buck output mode. Of course, in other embodiments, the mode selection signal can also be set to other types of signals to control the output mode of the core voltage regulator module 106, which is not limited here.

[0073] Please continue to refer to this. Figure 1 In this embodiment, the brake power supply chip also integrates a wheel speed sensor power supply module 116. The wheel speed sensor power supply module 116 is used to convert the wheel speed signal output by the wheel speed sensor outside the chip into a digital signal and output it to the MCU. The wheel speed sensor power supply module 116 is also used to supply power to the wheel speed sensor.

[0074] Please continue to refer to this. Figure 1In this embodiment, the braking power chip also integrates a voltage tracking module 117. The voltage tracking module 117 tracks the first supply voltage V2, the second supply voltage V3, the third supply voltage V4, the voltage divider feedback voltage V6, and the switching / linear buck supply voltage V5, and supplies power to the external sensor based on the tracked voltage. Specifically, the voltage tracking module 117 tracks the first supply voltage V2, the second supply voltage V3, the third supply voltage V4, the voltage divider feedback voltage V6, and the switching / linear buck supply voltage V5. If the external sensor requires a 3.3V supply voltage, the voltage tracking module 117 supplies power to the external sensor based on the required voltage from the tracked voltages. If the external sensor requires a 5V supply voltage, the voltage tracking module 117 supplies power to the external sensor based on the required voltage from the tracked voltages.

[0075] Please continue to refer to this. Figure 1 The braking power chip in this embodiment also integrates an internal power supply module 118, which includes an internal digital power supply unit 1182 and an internal analog power supply unit 1181.

[0076] The internal digital power supply unit 1182 is used to power the digital function modules within the chip, and the internal analog power supply unit 1181 is used to power the analog function modules within the chip. Furthermore, the output voltages of both the internal digital power supply unit 1182 and the internal analog power supply unit 1181 are also output to the voltage monitoring module 110. The voltage monitoring module 110 monitors the output voltages of both units to promptly detect undervoltage or overvoltage in their respective output voltages.

[0077] In this embodiment, both the internal digital power supply unit 1182 and the internal analog power supply unit 1181 can be configured as LDO circuits. That is, the internal power supply module 118 is configured with two discrete LDO circuits to provide power to the digital function module and the analog function module in the chip, respectively.

[0078] from Figure 1 As can be seen from the diagram, the external power supply voltage VBAT is connected to the internal power supply module 118 to provide input voltage for the internal digital power supply unit 1182 and the internal analog power supply unit 1181, thereby enabling the internal digital power supply unit 1182 and the internal analog power supply unit 1181 to convert the external power supply voltage VBAT into digital power supply voltage and analog power supply voltage for external output, respectively.

[0079] For example, the internal digital power supply unit 1182 needs to convert the 48V external power supply voltage VBAT to a 5V digital power supply voltage. Since the 48V external power supply voltage VBAT may fluctuate up to 75V, the high voltage difference between 48V~75V and 5V during the process of stepping down 48V or even 75V to 5V will cause the internal digital power supply unit 1182 to generate a lot of heat, thereby affecting the chip's performance.

[0080] In order to reduce the heat generated by the internal power supply during voltage conversion, this embodiment switches the external power supply voltage VBAT input to the internal power supply module 118 to the first step-down voltage V0 through the first switching switch SW1 after the chip is powered on normally, so that the first step-down voltage V0 is used as the input voltage of the internal digital power supply unit 1182 and the internal analog power supply unit 1181.

[0081] If the first step-down voltage V0 is set to 13.5V, then converting the 13.5V first step-down voltage V0 to a 5V digital power supply voltage can greatly reduce the heat generated by the internal digital power supply unit 1182 and the internal analog power supply unit 1181 during the voltage conversion process, thereby effectively improving the performance of the chip.

[0082] Please continue to refer to this. Figure 1 The internal power supply module 118 is also provided with a first reference source 1183 and a second reference source 1184.

[0083] The first reference source 1183 is used to provide a voltage reference for the functional module.

[0084] The functional modules may include the first-stage buck module 101, the second-stage buck module 102, the first linear regulator module 103, the second linear regulator module 104, the third linear regulator module 105, the core regulator module 106, the analog-to-digital converter module 115, the first current sensing amplifier module, the second current sensing amplifier module, and the logic control module 111, etc., which are not limited here.

[0085] The second reference source 1184 is used to provide a voltage reference for the safety monitoring module.

[0086] The safety monitoring module may include the safety shutdown module 114, the safety status output module 120, and the voltage monitoring module 110.

[0087] Therefore, by setting the first reference source 1183 and the second reference source 1184, the independence between the functional modules and the security monitoring module within the chip is ensured, thereby effectively suppressing common-cause failures caused by the functional modules and the security monitoring module using the same reference source, ensuring the functionality of the functional modules, and further improving the security of the chip.

[0088] In this embodiment, the first reference source and the second reference source monitor each other.

[0089] The specific principle of mutual monitoring between the first reference source and the second reference source is as follows: the voltage reference output by the first reference source generates a first undervoltage threshold through voltage division by a device, the voltage reference output by the second reference source generates a second undervoltage threshold through voltage division by a device, the voltage reference output by the first reference source is compared with the second undervoltage threshold, and the voltage reference output by the second reference source is compared with the first undervoltage threshold.

[0090] If the voltage reference output by the first reference source is less than the second undervoltage threshold, the logic control module outputs a first low-voltage fault signal based on the comparison result; if the voltage reference output by the second reference source is less than the first undervoltage threshold, the logic control module outputs a second low-voltage fault signal based on the comparison result, thereby realizing mutual monitoring between the first and second reference sources.

[0091] Furthermore, the specific scheme for device voltage division may include: connecting the output of the first / second reference source to a diode-connected MOS device to generate a first / second undervoltage threshold of approximately 0.7V.

[0092] Please refer to Figure 3 Based on the braking power supply chip provided in this embodiment, this embodiment also provides a power-on method for the braking power supply chip, the specific method including the following steps: S100: The internal power supply module of the braking power chip supplies power to each module within the chip after receiving an external wake-up signal and an external power supply.

[0093] S200: After being powered by the external input power supply and the internal power supply module, the first-stage step-down module outputs the first step-down voltage to the second-stage step-down module.

[0094] S300: After the second step-down module is input with the first step-down voltage, it outputs the second step-down voltage to the core voltage regulator module.

[0095] S400: After the core voltage regulator module is input with the second step-down voltage, it outputs a linear step-down power supply voltage or a switching step-down power supply voltage to the MCU according to the mode selection signal, so as to power the core of the MCU.

[0096] The power-on method for the braking power supply chip provided in this embodiment first wakes up the internal power supply module within the chip to supply power to the various modules within the chip. Then, the first-stage buck module, the second-stage buck module, and the core voltage regulator module are powered on sequentially, so that the core voltage regulator module outputs a linear buck supply voltage or a switching buck supply voltage to the MCU according to the mode selection signal to power the core of the MCU, thereby ensuring the power-on safety of the chip.

[0097] After the core voltage regulator module supplies power to the MCU core, the following steps are also included: After the core voltage regulator module supplies power to the MCU core, the logic control module outputs a first fault injection signal to the core voltage regulator module to inject a fault into the core voltage regulator module during the chip's power-on phase. The detection result is then fed back to the MCU, thus enabling the core voltage regulator module to self-test whether its fault diagnosis function is normal. Furthermore, the self-diagnosis schemes of the first, second, and third linear voltage regulator modules are similar to those of the core voltage regulator module and are not limited here.

[0098] In other embodiments, a braking system is also provided, the braking system including the braking power supply chip, three-phase brushless motor, solenoid valve and MCU provided in any of the above embodiments.

[0099] In other embodiments, a vehicle chassis is also provided, the vehicle chassis including the braking system, and each tire is equipped with at least one brake power chip provided in any of the above embodiments, that is, the vehicle chassis is equipped with at least four brake power chips.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A braking power supply chip, characterized in that, include: A first-stage buck module is used to perform a first step-down on the external power supply voltage and output a first step-down voltage; it is also used to perform a first step-up on the external power supply voltage and output a first drive voltage to the gate of its internal power transistor, wherein the difference between the first drive voltage and the external power supply voltage is greater than or equal to the threshold voltage of the power transistor in the first-stage buck module; the external power supply voltage is greater than or equal to 48V; The secondary step-down module is used to perform a second step-down on the first step-down voltage and output the second step-down voltage; it is also used to perform a third step-down on the external power supply voltage and output a second drive voltage to the gate of its internal power transistor, wherein the difference between the second drive voltage and the first step-down voltage is greater than or equal to the threshold voltage of the power transistor in the secondary step-down module. The core voltage regulator module is used to convert the second step-down voltage into a linear step-down supply voltage or a switching step-down supply voltage according to the mode selection signal; it is also used to perform a fourth step-down on the external power supply voltage and output a third drive voltage to the gate of the external power transistor, wherein the difference between the third drive voltage and the second step-down voltage is greater than or equal to the threshold voltage of the power transistor in the core voltage regulator module. The primary step-down module, the secondary step-down module, and the core voltage regulator module are all integrated into a single chip.

2. The braking power supply chip according to claim 1, characterized in that, It also integrates a first linear voltage regulator module. This is used to perform a first linear regulation on the second step-down voltage and output a first supply voltage, which is used to power the first I / O interface of the MCU or the first CAN interface of the system. The second linear regulator module is used to perform second linear regulation on the second step-down voltage and output a second power supply voltage, which is used to power the second I / O interface of the MCU or the second CAN interface of the system. The third linear regulator module is used to perform third linear regulation on the second step-down voltage and output a third power supply voltage, which is used to power the analog-to-digital converter in the MCU.

3. The braking power supply chip according to claim 2, characterized in that, The second step-down voltage is 6.5V or 7.2V, the corresponding output current is 1.4A, and the operating frequency of the second step-down module is 465KHz; The first power supply voltage is 5V, the accuracy of the first power supply voltage is ±2%, and the output current corresponding to the first power supply voltage is 250mA; The second power supply voltage is 3.3V or 5.0V, the accuracy of the second power supply voltage is ±2%, and the output current corresponding to the second power supply voltage is 250mA; The third power supply voltage is 5.0V, the accuracy of the third power supply voltage is ±1%, and the output current corresponding to the third power supply voltage is 100mA; Both the linear step-down power supply voltage and the switching step-down power supply voltage are between 0.8V and 5.0V. The output current corresponding to the linear step-down power supply voltage is 0.8A, and the output current corresponding to the switching step-down power supply voltage is 1.5A.

4. The braking power supply chip according to claim 2, characterized in that, It also integrates a voltage monitoring module, which is used to detect the first step-down voltage, the second step-down voltage, the first supply voltage, the second supply voltage, the third supply voltage, the switching step-down supply voltage, and the linear step-down supply voltage, and output corresponding fault signals according to the faults detected in each voltage. The fault signals represent the undervoltage or overvoltage of the first step-down voltage, the second step-down voltage, the first supply voltage, the second supply voltage, the third supply voltage, the switching step-down supply voltage, and the linear step-down supply voltage, respectively.

5. The braking power supply chip according to claim 4, characterized in that, It also integrates a logic control module, which is used to transmit the fault signal output by the voltage monitoring module to the MCU so that the MCU can determine the specific fault of the corresponding module; It also integrates a safety status output module, which is used to transmit the specific fault of the corresponding module to the braking actuator outside the chip when the MCU determines the specific fault of the corresponding module, and output a system shutdown signal to shut down the braking actuator.

6. The braking power supply chip according to claim 4, characterized in that, The logic control module is also used to directly output a first shutdown drive signal based on the fault signal output by the voltage monitoring module. It also integrates a safety shutdown module, which cuts off the power input of the first-stage buck module according to the first shutdown drive signal.

7. The braking power supply chip according to claim 6, characterized in that, The first-stage buck module includes a first withstand voltage NMOS transistor, a second withstand voltage NMOS transistor, and a first low-side NMOS transistor. The drain of the first withstand voltage NMOS transistor is connected to the external power supply voltage, and the source of the first withstand voltage NMOS transistor is connected to the drain of the second withstand voltage NMOS transistor. The first withstand voltage NMOS transistor is turned off according to the first turn-off drive signal connected to its gate. The source of the second withstand voltage NMOS transistor is connected to the drain of the first low-side NMOS transistor. The source of the first low-side NMOS transistor is connected to ground. The withstand voltage of the first voltage-rated NMOS transistor, the second voltage-rated NMOS transistor, and the first low-side NMOS transistor is all greater than or equal to 80V.

8. The braking power supply chip according to claim 2, characterized in that, It also integrates an analog-to-digital conversion module, which is used for: The first supply voltage, the second supply voltage, the third supply voltage, the switching buck supply voltage, and the linear buck supply voltage are all converted from analog to digital into corresponding digital signals and output to the MCU. The externally input voltage signal is converted from analog to digital and then output to the logic control module. The external input mode selection signal is transmitted to the core voltage regulator module; It also integrates a wheel speed sensor power supply module, which is used to convert the wheel speed signal output by the external wheel speed sensor into a digital signal and output it to the MCU. The wheel speed sensor power supply module is also used to power the wheel speed sensor.

9. A power-on method for a braking power supply chip, characterized in that, Based on the braking power supply chip according to any one of claims 5 to 8, the power-on method includes: The internal power supply module of the braking power chip supplies power to each module within the chip after receiving an external wake-up signal and an external power supply. After being powered by the external input power supply and the internal power supply module, the first-stage buck module outputs a first buck voltage to the second-stage buck module; After the first step-down voltage is input, the secondary step-down module outputs the second step-down voltage to the core voltage regulator module; After the core voltage regulator module is input with the second step-down voltage, it outputs a linear step-down power supply voltage or a switching step-down power supply voltage to the MCU according to the mode selection signal, so as to power the core of the MCU. After the first, second, and third linear regulator modules are all input with the second step-down voltage, they output the first, second, and third supply voltages respectively to power the MCU's I / O interface, the system's CAN interface, and the MCU's ADC.

10. The power-on method for the braking power supply chip according to claim 9, characterized in that, The power-on process of the chip also includes: The logic control module outputs a first fault injection signal to the core voltage regulator module, the first-stage buck module, the second-stage buck module, the first linear voltage regulator module, the second linear voltage regulator module, and the third linear voltage regulator module; After the core voltage regulator module supplies power to the core of the MCU, it also includes: feeding back the detection structure corresponding to the first fault injection signal to the MCU.

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