High-precision Hall current sensor output sampling circuit

Abstract

The utility model discloses a high-precision Hall current sensor output sampling circuit, which comprises a Hall power supply output circuit, a Hall current sensor ADC sampling circuit, a power supply voltage sampling circuit and an IIC communication circuit, and is characterized in that the Hall power supply output circuit comprises a Hall sensor power supply U1, a capacitor C1, a capacitor C2 and a diode D1; when an EN signal reaches a high level, the U1 outputs power supply voltage HALL POWER, the C1 filters power supply output, the D1 suppresses surge voltage generated by plugging and unplugging a connector and prevents the U1 from being broken down and burnt out, the C2 prevents static electricity generated by a connector port, and when the requirement for the precision of a current value monitored by a Hall sensor is very high, the circuit can provide sampling data with the precision as high as 16 bits. When the requirement for the transmission speed of sampled data is very high, the circuit provides the highest sampling transmission speed of 3.4 MHz bit / s through an IIC signal.

Description

Technical Field

[0001] The invention belongs to the field of automobile battery management systems, and in particular relates to a high-precision Hall current sensor output sampling circuit. Background Art

[0002] The automotive battery management system samples the output voltage of the external Hall current sensor to determine the output status of the vehicle battery. The general design directly connects the output end of the Hall current sensor to the sampling chip port for sampling. This design is limited by the sampling accuracy of the sampling chip and cannot meet some high-precision sampling requirements. Summary of the invention

[0003] To achieve the above object, the technical solution of the present invention is as follows: a high-precision Hall current sensor output sampling circuit, the circuit includes a power supply output circuit, a Hall current sensor ADC sampling circuit, a power supply voltage sampling circuit and an IIC communication circuit.

[0004] As an improvement of the utility model, the power output circuit includes a Hall sensor power supply U1, a capacitor C1, a capacitor C2 and a diode D1. When the EN signal reaches a high level, U1 outputs a power supply voltage HALL POWER, C1 filters the power output, D1 suppresses the surge voltage generated by plugging and unplugging the connector to prevent U1 from being broken down and burned, and C2 prevents static electricity generated by the connector port.

[0005] As an improvement of the utility model, the Hall current sensor U2 in the Hall current sensor ADC sampling circuit samples the output current of the external power supply, converts it into voltage and outputs it indirectly to U3 and the ADC conversion chip through the HALL CH1 and HALL CH2 channels via the external interface.

[0006] As an improvement of the present utility model, the resistors R7 and R8 in the ADC sampling circuit of the Hall current sensor and the external circuit form a first voltage divider circuit. The voltage at the ends of the resistors R7 and R8 is output to U3 and the ADC port and converted into 16-bit ADC sampling data after being limited by the resistors R3 and R4 and filtered by the capacitors C4 and C5.

[0007] As an improvement of the present invention, the resistors R1 and R2 in the power supply voltage sampling circuit form a second voltage divider circuit. The voltage at the end of the resistor R2 is filtered by the capacitor C3 and output to the U3 and ADC port to be converted into 16-bit ADC sampling data. The U3 power supply Power AD is also converted into 16-bit ADC sampling data.

[0008] As an improvement of the present invention, the IIC communication circuit U3 packages the 16-bit ADC sampling data converted by HALL CH1 AD, HALLCH2 AD, HALL POWER AD and POWER AD through IIC and sends them to U4 for processing.

[0009] Compared with the prior art, the beneficial effects of the present invention are:

[0010] ① When the accuracy of the current value monitored by the Hall sensor is very high, this circuit can provide sampling data with an accuracy of up to 16 bits;

[0011] ② When the sampling data transmission speed is very high, this invention provides a sampling transmission rate of up to 3.4MHz bit / s through the IIC signal;

[0012] ③D2 voltage stabilizing diode effectively suppresses surge voltage generated by plugging and unplugging connectors, preventing damage to the Hall sensor power supply;

[0013] ④This invention can support AD sampling of two single-channel Hall sensors or one dual-channel Hall sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the sampling circuit structure in this embodiment. DETAILED DESCRIPTION

[0015] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0016] Embodiment: This embodiment is a high-precision Hall current sensor output sampling circuit. This example shows the ADC sampling of a dual-channel Hall sensor.

[0017] like Figure 1As shown, the positive pole (+) of the power supply battery1 is connected in series to the power input pin of the U1 chip TPS7B4254-Q1 through a wire to supply power to it, and the negative pole is grounded; the high-level signal EN output by the U4 chip SAK-TC389QP-160F300S AE is connected in series to the enable pin of the U1 chip through a wire to enable the U1 chip to work normally; the output voltage HALL POWER of the U1 chip is connected in series to the power input pin of the external U2 Hall sensor DHAB S / 24 through a wire to supply power to it; one end of the 1nf 0603 capacitor C1 is connected to the output voltage HALL POWER of the U1 chip through a wire, and the other end is grounded through a wire; the cathode of the PMEG4010CEH diode is connected to the output voltage HALL POWER of the U1 chip through a wire, and the anode is grounded through a wire; one end of the 47K 0603 resistor R1 is connected to the output voltage HALL POWER of the U1 chip through a wire, and the other end is connected to the 10K The 0603 resistor R2 is also connected to the AD acquisition port 2 of the U3 chip ADS1115BQDGSRQ1 through a wire. The other end of resistor R2 is grounded through a wire; 100nf 0402 capacitor C3 is connected in parallel to resistor R2; one end of 10nf 0805 capacitor C2 is connected to U1 output voltage HALL POWER through a wire, and the other end is grounded through a wire; the output voltage of U2 Hall sensor DHAB S / 24 output channel CH1 is connected to 10nf 0805 capacitor C3, 100K0603 resistor R7, one end of 30K 0603 resistor R3, capacitor C3, the other end of resistor R7 is grounded through a wire, and the other end of resistor R3 is connected to U3's AD acquisition port 0 through a wire; the output voltage of U2 Hall sensor DHAB S / 24 output channel CH2 is connected to 10nf 0805 capacitor C6, 100K 0603 resistor R8, one end of 30K 0603 resistor R4, capacitor C6, the other end of resistor R8 is grounded through a wire, and the other end of resistor R4 is connected to U3's AD acquisition port 1 through a wire; 33nf One end of the 0402 capacitor C4 and capacitor C5 are connected to the AD acquisition port 0 and port 1 of the U3 chip through wires, and the other end is grounded through wires; the positive pole (+) of the power supply battery2 is connected in series to the power pin of the U3 chip through a wire to power it, and is connected to the 10K 0603 resistor R5 through a wire. One end of the resistor R6 provides a high level for it, and the negative pole is grounded; the IIC interface of the U3 chip is connected to the IIC interface of the U4 chip through a wire, and the other ends of the resistors R5 and R6 are connected to the IIC communication SCL signal and SDA signal through wires respectively.

[0018] The circuit includes: HALL POWER circuit; the power output circuit is composed of U1 chip, capacitor C1, capacitor C2, and diode D2. When the EN signal reaches a high level, the U1 chip outputs the power supply voltage HALL POWER, capacitor C1 filters the power output, D1 suppresses the surge voltage generated by plugging and unplugging the connector to prevent U1 from being broken down and burned, and capacitor C2 prevents static electricity generated by the connector port. Hall current sensor ADC sampling circuit: The Hall current sensor U2 samples the external power supply output current and converts it into voltage and directly outputs it to the U3 ADC conversion chip through the HALL CH1 and HALL CH2 channels through the external interface. Resistors R7, R8 and the external circuit form a voltage divider circuit. The voltage at the ends of resistors R7 and R8 is limited by resistors R3 and R4 and filtered by capacitors C4 and C5, and then output to the U3 ADC port to be converted into 16-bit ADC sampling data. Power supply voltage sampling circuit: Resistors R1 and R2 form a voltage divider circuit. The voltage at the end of resistor R2 is filtered by C3 and then output to the U3 ADC port to be converted into 16-bit ADC sampling data. U3 also converts the Power AD of Battery2 positive pole into 16-bit ADC sampling data. IIC communication circuit: U3 packages the 16-bit ADC sampling data converted from HALL CH1 AD, HALL CH2 AD, HALL POWER AD, and POWER AD through IIC and sends it to U4 for processing. Resistors R5 and R6 provide pull-up for IIC signal. Figure 1 As shown, the EN signal enables the Hall sensor power supply U1, U1 provides HALL POWER to power the Hall sensor, capacitor C1 filters to make the HAL POWER ripple voltage less than 50mv, D1 suppresses the surge voltage generated by plugging and unplugging the connector to prevent U1 from burning, and capacitor C2 is placed near the connector to prevent static electricity. The Hall current sensor U2 converts the sampled external total power output current into voltage and outputs the voltage through the two channels HALL CH1 and HALL CH2. Resistors R7, R8 and the external circuit form a voltage divider circuit. The divided voltage (R7, R8 terminal voltage) is output to the U3 ADC port after current limiting by resistors R3 and R4 and filtering by capacitors C4 and C5 to convert into 16-bit ADC sampling data. Capacitors C3 and C6 are placed near the connector to prevent static electricity. Resistors R1 and R2 form a voltage divider circuit. The voltage at the resistor R2 terminal (HALL POWER AD) is filtered by C3 and output to the U3 ADC port to convert into 16-bit ADC sampling data. The Power AD of Battery2 powered by U3 is also converted into 16-bit ADC sampling data. Finally, U3 transmits the 16-bit sampling data to U4 for processing via the IIC signal.

[0019] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A high-precision Hall current sensor output sampling circuit, characterized in that: The circuit includes a power output circuit, a Hall current sensor ADC sampling circuit, a power supply voltage sampling circuit and an IIC communication circuit. The resistors R7 and R8 in the Hall current sensor ADC sampling circuit and the external circuit constitute a first voltage divider circuit. The voltage at the ends of the resistors R7 and R8 is output to the U3 ADC port after being limited by the resistors R3 and R4 and filtered by the capacitors C4 and C5 and converted into 16-bit ADC sampling data. The resistors R1 and R2 in the power supply voltage sampling circuit constitute a second voltage divider circuit. The voltage at the end of the resistor R2 is output to the U3 ADC port after being filtered by the capacitor C3 and converted into 16-bit ADC sampling data. The Power AD at the positive pole of the U3 chip power supply Battery2 is also converted into 16-bit ADC sampling data.

2. A high-precision Hall current sensor output sampling circuit according to claim 1, characterized in that: The power output circuit includes a Hall sensor power supply U1, a capacitor C1, a capacitor C2 and a diode D1. When the EN signal reaches a high level, the Hall sensor power supply U1 outputs a power supply voltage HALL POWER, the capacitor C1 filters the power output, the diode D1 suppresses the surge voltage generated by plugging and unplugging the connector to prevent U1 from being broken down and burned, and the capacitor C2 prevents static electricity generated by the connector port.

3. A high-precision Hall current sensor output sampling circuit according to claim 1, characterized in that: The Hall current sensor U2 in the Hall current sensor ADC sampling circuit converts the sampled external power supply output current into voltage and directly outputs it to U3 and the ADC conversion chip through the HALL CH1 and HALL CH2 channels via the external interface.

4. A high-precision Hall current sensor output sampling circuit according to claim 1, characterized in that: The IIC communication circuit U3 packages the 16-bit ADC sampling data converted by HALL CH1 AD, HALL CH2 AD, HALL POWER AD, and POWER AD through IIC and sends them to the U4 chip for processing.

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