Tire pressure signal receiving circuit

Abstract

The utility model relates to the field of tire pressure sensors, in particular to a tire pressure signal receiving circuit which comprises a power supply module, an MCU (Microprogrammed Control Unit) module, a CAN (Controller Area Network) module and an RF (Radio Frequency) module, the output end of the power supply module is electrically connected with the MCU module, the CAN module and the RF module; the input end of the RF module is connected with an antenna ANT; the output end of the RF module is electrically connected with the input end of the MCU module, a communication interface of the MCU module is electrically connected with the CAN module, the power module supplies power to the MCU module, the CAN module and the RF module, the RF module receives tire pressure information, temperature and other data collected by the sensor through the antenna ANT and transmits the data to the MCU module, and the MCU module is electrically connected with the CAN module. The MCU module transmits data information such as tire pressure and temperature to a vehicle central controller through the CAN module, and the central controller displays and early warns the data such as the tire pressure information, so that the overall complexity of a receiving circuit is effectively reduced, and the use cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of tire pressure sensors, specifically to a tire pressure signal receiving circuit. Background Technology

[0002] A sensor is a detection device that acts as an extension of our sensory system. It can detect various physical, chemical, or biological quantities in the surrounding environment and convert these non-electrical quantities into electrical signals or other easily processed and transmitted signal forms according to certain rules, for subsequent measurement, control, display, or recording operations. The tire pressure receiving circuit of a tire pressure sensor is a key component of a tire pressure monitoring system (TPMS). Its main function is to receive wireless signals emitted by the tire pressure sensor and process the signals through demodulation and decoding to obtain information such as tire pressure and temperature.

[0003] For example, the invention patent with application number CN202111359397.X, entitled "Tire Pressure Detection Signal Receiving Circuit, System and Method," utilizes a synchronization module to synchronize and filter the received encoded baseband signal; a configuration module outputs a preset baud rate and a preset synchronization mode; a detection module detects the processed baseband signal based on the preset baud rate and outputs a valid signal and an actual baud rate; a clock generation module receives the preset baud rate or the actual baud rate and outputs a baud rate clock; a frame synchronization module receives the valid signal and the baud rate clock, samples the valid signal, matches the sampled signal with the preset synchronization mode, and outputs a buffered signal; a decoding module receives the buffered signal and the baud rate clock and decodes the buffered signal; and a configuration module receives the decoded data and sends it to the application module. However, the overall structure is complex, resulting in high usage costs. Utility Model Content

[0004] The purpose of this invention is to provide a tire pressure signal receiving circuit, which aims to improve the problem that conventional tire pressure signal receiving circuits have a complex overall structure, resulting in high operating costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A tire pressure signal receiving circuit includes a power supply module, an MCU module, a CAN module, and an RF module;

[0007] The input terminal of the power module is electrically connected to an external power source, and the output terminal of the power module is electrically connected to the MCU module, CAN module, and RF module. The input terminal of the RF module is connected to an antenna ANT to receive data such as pressure and temperature from the sensor. The output terminal of the RF module is electrically connected to the input terminal of the MCU module, the communication interface of the MCU module is electrically connected to the CAN module, and the output terminal of the CAN module communicates with an external central control unit.

[0008] Furthermore, the power supply module includes a voltage regulator chip U1, a voltage regulator chip U5, a varistor ZB1, a diode D1, a diode D2B, a diode D2A, a polarized capacitor C4, a polarized capacitor C6, a polarized capacitor C12, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C5, a capacitor C7, a capacitor C8, and resistors R1 and R2.

[0009] The positive terminal of the external backup power supply is electrically connected to one end of the varistor ZB1, one end of the resistor R1, the positive terminal of the diode D1, and one end of the capacitor C2. The other end of the capacitor C2 is electrically connected to one end of the capacitor C3.

[0010] The negative terminal of diode D1 is electrically connected to the positive terminal of polarized capacitor C4, one end of capacitor C5, and pin 1 of voltage regulator chip U1, and is also electrically connected to an external +12V voltage. Pin 3 of voltage regulator chip U1 is electrically connected to the positive terminal of polarized capacitor C6, one end of capacitor C7, and pins 1 and 3 of voltage regulator chip U5, and outputs +5V voltage to the CAN module. Pin 5 of voltage regulator chip U5 is electrically connected to one end of capacitor C8 and the positive terminal of polarized capacitor C12. The other end of resistor R1 is electrically connected to one end of resistor R2, one end of capacitor C1, the positive terminal of diode D2B, and the negative terminal of diode D2A. The negative terminal of diode D2B and pin 5 of voltage regulator chip U5 both output +3.3V voltage to the MCU module, CAN module, and RF module.

[0011] The other end of the varistor ZB1, the other end of the capacitor C3, the negative terminal of the polarized capacitor C4, the other end of the capacitor C5, the negative terminal of the polarized capacitor C6, the other end of the capacitor C7, the other end of the capacitor C8, the negative terminal of the polarized capacitor C12, the other end of the capacitor C1, the other end of the resistor R2, the positive terminal of the diode D2A, and pin 2 of the voltage regulator chip U1 and pin 2 of the voltage regulator chip U5 are all grounded.

[0012] Furthermore, the MCU module includes a control chip U2, resistors R39, R41, and R42, and capacitors C36, C41, and C44.

[0013] The power module outputs a +3.3V voltage to one end of resistor R41, one end of resistor R42, one end of resistor R39, one end of capacitor C44, and pins 12 and 35 of control chip U2; an external +12V voltage is input to pin 37 of control chip U2.

[0014] The other end of resistor R39 is electrically connected to one end of capacitor C34 and pin 4 of control chip U2; pin 10 of control chip U2 is electrically connected to one end of capacitor C41; the other end of resistor R41 is electrically connected to pins 14 and 15 of control chip U2; and the other end of resistor R42 is electrically connected to pin 13 of control chip U2.

[0015] Pins 13, 14, 16, 17, 22, 23, and 24 of the control chip U2 are all electrically connected to the output of the RF module; pins 31, 33, and 34 of the control chip U2 are all electrically connected to the CAN module.

[0016] The other end of capacitor C34, the other end of capacitor C41, the other end of capacitor C44, and pins 11 and 36 of control chip U2 are all grounded.

[0017] Furthermore, it also includes a clock module, which includes a crystal oscillator XT1, a resistor R34, and capacitors C35 and C36;

[0018] Pin 8 of the control chip U2 is electrically connected to one end of resistor R34, one end of crystal oscillator XT1, and one end of capacitor C35. Pin 9 of the control chip U2 is electrically connected to the other end of resistor R34, the other end of crystal oscillator XT1, and one end of capacitor C36. The other ends of capacitors C35 and C36 are both grounded.

[0019] Furthermore, the RT module includes an RF receiver chip U4, a crystal oscillator XT2, inductors L1, L2, L3, L4, C19, and capacitors C18, C17, C16, C15, C10, C11, C13, and C14.

[0020] The power module outputs a +3.3V voltage to one end of capacitor C10, one end of capacitor C11, and pins 4 and 7 of the RF receiver chip U4; the antenna ANT is electrically connected to one end of capacitor C18 and one end of inductor C19, and the other end of inductor C19 is electrically connected to one end of capacitor C17, one end of inductor L4, one end of inductor L3, and one end of capacitor C16.

[0021] The other end of inductor L3 is electrically connected to one end of capacitor C15, one end of inductor L1, and pin 2 of RF receiver chip U4; the other end of capacitor C16 is electrically connected to one end of inductor L2, the other end of inductor L1, and pin 1 of RF receiver chip U4; pin 13 of RF receiver chip U4 is electrically connected to one end of crystal oscillator XT2 and one end of capacitor C14; pin 14 of RF receiver chip U4 is electrically connected to the other end of crystal oscillator XT2 and one end of capacitor C13; pins 8, 9, 10, 11, 12, 15, and 16 of RF receiver chip U4 are all electrically connected to the signal input terminal of the MCU module.

[0022] The other ends of capacitor C18, capacitor C17, inductor L4, capacitor C15, inductor L2, capacitor C10, capacitor C11, capacitor C13, capacitor C14, and pins 5, 6, and 17 of the RF receiver chip are all grounded.

[0023] Furthermore, the CAN module includes a transceiver chip U3, diodes ZD2A, ZD2B, ZD3A, ZD3B, capacitors C47, C46, ​​C45, C49, C50, and resistor R43.

[0024] The power module outputs +3.3V voltage to one end of capacitor C47 and pin 5 of transceiver chip U3, and the power module outputs +5V voltage to pin 3 of transceiver chip U3; pins 1, 4, and 8 of transceiver chip U3 are all electrically connected to the MCU module.

[0025] Pin 6 of the transceiver chip U3 is electrically connected to the negative terminal of diode ZD3A, one end of capacitor C49, and one end of resistor R43, and is connected to the CAN-L interface for communication with an external central control unit; the positive terminal of diode ZD3A is electrically connected to the positive terminal of diode ZD3B, and the other end of capacitor C49 is electrically connected to one end of capacitor C50; pin 7 of the transceiver chip U3 is electrically connected to the negative terminal of diode ZD2A, one end of capacitor C46, ​​and the other end of resistor R43, and is connected to the CAN-H interface for communication with an external central control unit; the positive terminal of diode ZD2A is electrically connected to the positive terminal of diode ZD2B, and the other end of capacitor C46 is electrically connected to one end of capacitor C45;

[0026] The other ends of capacitor C47, capacitor C45, capacitor C50, the negative terminal of diode ZD2B, the negative terminal of diode ZD3B, and pin 2 of transceiver chip U3 are all grounded.

[0027] Furthermore, diodes ZD2A, ZD2B, ZD3A, and ZD3B are all Schottky diodes.

[0028] Furthermore, it also includes an IGN module, whose signal input terminal is connected to the external vehicle ignition switch, and whose signal output terminal is electrically connected to the MCU module. The IGN module monitors the vehicle status.

[0029] Furthermore, the IGN module includes diode D5A, diode D5B, capacitor C9, capacitor C2, and resistors R10, R11, R12, and R14.

[0030] The power module outputs a +3.3V voltage to the negative terminal of diode D5B; one end of resistor R11 is electrically connected to the positive terminal of the external backup power supply, and the other end of resistor R11 is electrically connected to one end of capacitor C9, one end of resistor R10, and one end of resistor R14, and serves as an input terminal connected to the external vehicle ignition switch; the other end of resistor R14 is electrically connected to one end of resistor R12, one end of capacitor C20, the negative terminal of diode D5A, and the positive terminal of diode D5B, and serves as an output terminal connected to the MCU module.

[0031] The other end of capacitor C9, the other end of resistor R10, the other end of resistor R12, the other end of capacitor C20, and the positive terminal of diode D5A are all grounded.

[0032] By adopting the above technical solution, this utility model has the following advantages compared with the prior art:

[0033] The power module supplies power to the MCU module, CAN module, and RF module. The RF module receives tire pressure and temperature data collected by the sensors through the antenna ANT and transmits it to the MCU module. The MCU module transmits the tire pressure and temperature data to the vehicle's central control unit through the CAN module. The central control unit displays and issues warnings on the tire pressure and other data, effectively reducing the overall complexity of the receiving circuit and lowering the cost of use. Attached Figure Description

[0034] Figure 1 This is a circuit diagram of the power module of the tire pressure signal receiving circuit described in this utility model;

[0035] Figure 2 This is a circuit diagram of the MCU module, CAN module, and RF module of the tire pressure signal receiving circuit described in this utility model;

[0036] Figure 3 This is a circuit diagram of the IGN module of the tire pressure signal receiving circuit described in this utility model. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0038] Additionally, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are all based on the orientation or positional relationship shown in the accompanying drawings. They are merely for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element of this utility model must have a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0039] When an element is referred to as being "fixed to," "set on," or "contained on" another element, it can be directly on or indirectly on that other element. When an element is referred to as being "connected to," it can be directly connected to or indirectly connected to that other element.

[0040] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] Example

[0042] Please refer to Figure 1-3 As shown, this embodiment provides a tire pressure signal receiving circuit, including a power module, an MCU module, a CAN module, and an RF module. The input terminal of the power module is electrically connected to an external power source, and the output terminal of the power module is electrically connected to the MCU module, the CAN module, and the RF module. An antenna ANT is connected to the input terminal of the RF module to receive pressure, temperature, and other data from the sensor; the output terminal of the RF module is electrically connected to the input terminal of the MCU module; the communication interface of the MCU module is electrically connected to the CAN module; and the output terminal of the CAN module communicates with an external central control unit.

[0043] The power module supplies power to the MCU module, CAN module, and RF module. The RF module receives tire pressure and temperature data collected by the sensors through the antenna ANT and transmits it to the MCU module. The MCU module transmits the tire pressure and temperature data to the vehicle's central control unit through the CAN module. The central control unit displays and issues warnings on the tire pressure and other data, effectively reducing the overall complexity of the receiving circuit and lowering the cost of use.

[0044] Please refer to Figure 1 As shown, specifically, the power supply module includes voltage regulator chip U1, voltage regulator chip U5, varistor ZB1, diode D1, diode D2B, diode D2A, polarized capacitor C4, polarized capacitor C6, polarized capacitor C12, capacitor C1, capacitor C2, capacitor C3, capacitor C5, capacitor C7, capacitor C8, and resistors R1 and R2. In this embodiment, the voltage regulator chip U1 is model LM2937, and the voltage regulator chip U5 is model TCR2EF33.

[0045] The external backup power supply is electrically connected to one end of the varistor ZB1, one end of the resistor R1, the positive terminal of the diode D1, and one end of the capacitor C2. The other end of the capacitor C2 is electrically connected to one end of the capacitor C3.

[0046] The negative terminal of diode D1 is electrically connected to the positive terminal of polarized capacitor C4, one end of capacitor C5, and pin 1 of voltage regulator chip U1, and is also electrically connected to an external +12V voltage. Pin 3 of voltage regulator chip U1 is electrically connected to the positive terminal of polarized capacitor C6, one end of capacitor C7, and pins 1 and 3 of voltage regulator chip U5, and outputs +5V voltage to the CAN module. Pin 5 of voltage regulator chip U5 is electrically connected to one end of capacitor C8 and the positive terminal of polarized capacitor C12. The other end of resistor R1 is electrically connected to one end of resistor R2, one end of capacitor C1, the positive terminal of diode D2B, and the negative terminal of diode D2A. The negative terminal of diode D2B and pin 5 of voltage regulator chip U5 both output +3.3V voltage to the MCU module, CAN module, and RF module.

[0047] The other end of varistor ZB1, the other end of capacitor C3, the negative terminal of polarized capacitor C4, the other end of capacitor C5, the negative terminal of polarized capacitor C6, the other end of capacitor C7, the other end of capacitor C8, the negative terminal of polarized capacitor C12, the other end of capacitor C1, the other end of resistor R2, the positive terminal of diode D2A, and pin 2 of voltage regulator chip U1 and voltage regulator chip U5 are all grounded.

[0048] The power module forms a multi-stage voltage regulation structure based on voltage regulator chips U1 and U5, and connects to an external backup power supply via a BAT interface. In the event of a +12V main power supply failure, stable power supply is achieved through the backup power supply. Polarized capacitors C4, C5, C6, C7, C12, and C8 form an input filter capacitor network to filter out high-frequency noise and voltage fluctuations. Diode D2A serves as input reverse connection protection to prevent damage to the overall circuit if the power supply is connected in reverse.

[0049] Please refer to Figure 2 As shown, specifically, the MCU module includes a control chip U2, resistors R39, R41, and R42, and capacitors C36, C41, and C44. In this embodiment, the control chip U2 is model UPD78F1828.

[0050] The power module outputs a +3.3V voltage to one end of resistor R41, one end of resistor R42, one end of resistor R39, one end of capacitor C44, and pins 12 and 35 of control chip U2. Specifically, the negative terminal of diode D2B and pin 5 of voltage regulator chip U5 are electrically connected to one end of resistor R41, one end of resistor R42, one end of resistor R39, one end of capacitor C44, and pins 12 and 35 of control chip U2. An external +12V voltage is input to pin 37 of control chip U2.

[0051] The other end of resistor R39 is electrically connected to one end of capacitor C34 and pin 4 of control chip U2; pin 10 of control chip U2 is electrically connected to one end of capacitor C41; the other end of resistor R41 is electrically connected to pins 14 and 15 of control chip U2, and the other end of resistor R42 is electrically connected to pin 13 of control chip U2. Pins 13, 14, 16, 17, 22, 23, and 24 of control chip U2 are all electrically connected to the output of the RF module. Pins 31, 33, and 34 of control chip U2 are all electrically connected to the CAN module.

[0052] The other end of capacitor C34, the other end of capacitor C41, the other end of capacitor C44, and pins 11 and 36 of control chip U2 are all grounded.

[0053] Furthermore, the tire pressure signal receiving circuit also includes a clock module, which comprises a crystal oscillator XT1, a resistor R34, and capacitors C35 and C36. Pin 8 of the control chip U2 is electrically connected to one end of resistor R34, one end of crystal oscillator XT1, and one end of capacitor C35. Pin 9 of the control chip U2 is electrically connected to the other end of resistor R34, the other end of crystal oscillator XT1, and one end of capacitor C36. The other ends of capacitors C35 and C36 are both grounded. Crystal oscillator XT1, resistor R34, and capacitors C35 and C36, together with the internal inverter of control chip U2, form a Pierce oscillator, providing a stable clock for control chip U2. This also achieves a small size, reduces the overall structural size, and simplifies the overall circuit structure, further reducing usage costs.

[0054] Specifically, the RT module includes an RF receiver chip U4, a crystal oscillator XT2, inductors L1, L2, L3, L4, C19, and capacitors C18, C17, C16, C15, C10, C11, C13, and C14; in this embodiment, the RF receiver chip U4 is model CMT2219B.

[0055] The power module outputs +3.3V to one end of capacitor C10, one end of capacitor C11, and pins 4 and 7 of the RF receiver chip U4; that is, the negative terminal of diode D2B and pin 5 of voltage regulator chip U5 are electrically connected to one end of capacitor C10, one end of capacitor C11, and pins 4 and 7 of RF receiver chip U4. The antenna ANT is electrically connected to one end of capacitor C18 and one end of inductor C19. The other end of inductor C19 is electrically connected to one end of capacitor C17, one end of inductor L4, one end of inductor L3, and one end of capacitor C16.

[0056] The other end of inductor L3 is electrically connected to one end of capacitor C15, one end of inductor L1, and pin 2 of RF receiver chip U4; the other end of capacitor C16 is electrically connected to one end of inductor L2, the other end of inductor L1, and pin 1 of RF receiver chip U4. Pin 13 of RF receiver chip U4 is electrically connected to one end of crystal oscillator XT2 and one end of capacitor C14, and pin 14 of RF receiver chip U4 is electrically connected to the other end of crystal oscillator XT2 and one end of capacitor C13. Pins 8, 9, 10, 11, 12, 15, and 16 of the RF receiver chip U4 are all electrically connected to the signal input terminals of the MCU module. Specifically, pin 8 of the RF chip U4 is electrically connected to pin 22 of the control chip U2, pin 9 of the RF chip U4 is electrically connected to pin 13 of the control chip U2, pin 10 of the RF chip U4 is electrically connected to pin 14 of the control chip U2, pin 11 of the RF chip U4 is electrically connected to pin 16 of the control chip U2, pin 12 of the RF chip U4 is electrically connected to pin 17 of the control chip U2, pin 15 of the RF chip U4 is electrically connected to pin 24 of the control chip U2, and pin 16 of the RF chip U4 is electrically connected to pin 23 of the control chip U2.

[0057] The other ends of capacitor C18, capacitor C17, inductor L4, capacitor C15, inductor L2, capacitor C10, capacitor C11, capacitor C13, capacitor C14, and pins 5, 6, and 17 of the RF receiver chip are all grounded.

[0058] Capacitors C15, C16, and C17, along with inductors L1 and L2, form a filter circuit that ensures only specific frequency radio frequency (RF) signals are allowed to pass through, filtering out unwanted frequencies and effectively reducing the impact of interference signals on signal transmission. Crystal oscillator XT2, connected to capacitors C13 and C14, provides a stable clock signal to the RF receiver chip U4. This provides a time reference for the RF receiver chip U4's RF signal modulation and demodulation operations, ensuring that the RF receiver chip U4 can accurately process RF signals.

[0059] Specifically, the CAN module includes transceiver chip U3, diodes ZD2A, ZD2B, ZD3A, ZD3B, capacitors C47, C46, ​​C45, C49, C50, and resistor R43; in this embodiment, the transceiver chip U3 is model TLE9251V.

[0060] The power module outputs +3.3V voltage to one end of capacitor C47 and pin 5 of transceiver chip U3 (i.e., the negative terminal of diode D2B). Pin 5 of voltage regulator chip U5 is also electrically connected to one end of capacitor C47 and pin 5 of transceiver chip U3. The power module outputs +5V voltage to pin 3 of transceiver chip U3; that is, pin 3 of voltage regulator chip U1 is electrically connected to pin 3 of transceiver chip U3. Pins 1, 4, and 8 of transceiver chip U3 are all electrically connected to the MCU module; specifically, pin 1 of transceiver chip U3 serves as the transmitting port and is electrically connected to pin 34 of control chip U2, pin 4 of transceiver chip U3 serves as the receiving port and is electrically connected to pin 33 of control chip U2, and pin 8 of transceiver chip U3 is electrically connected to pin 31 of control chip U2.

[0061] Pin 6 of transceiver chip U3 is electrically connected to the negative terminal of diode ZD3A, one end of capacitor C49, and one end of resistor R43, and is connected to the CAN-L interface for communication with an external central control unit. The positive terminal of diode ZD3A is electrically connected to the positive terminal of diode ZD3B, and the other end of capacitor C49 is electrically connected to one end of capacitor C50. Pin 7 of transceiver chip U3 is electrically connected to the negative terminal of diode ZD2A, one end of capacitor C46, ​​and the other end of resistor R43, and is connected to the CAN-H interface for communication with an external central control unit. The positive terminal of diode ZD2A is electrically connected to the positive terminal of diode ZD2B, and the other end of capacitor C46 is electrically connected to one end of capacitor C45.

[0062] The other ends of capacitors C47, C45, and C50, the cathodes of diodes ZD2B and ZD3B, and pin 2 of transceiver chip U3 are all grounded. In this embodiment, diodes ZD2A, ZD2B, ZD3A, and ZD3B are all Schottky diodes.

[0063] Transceiver chip U3 receives tire pressure, temperature, and other signals from control chip U2 via pin 1, converts these signals into differential signals, and sends them to the CAN bus via pins 7 and 6. Converting tire pressure, temperature, and other signals into differential signals effectively improves anti-interference capabilities, reduces the impact of electromagnetic interference on the signal, and ensures signal stability during transmission. Transceiver chip U3 converts the differential signals from the CAN bus into digital signals and transmits them to control chip U2 via pin 4, enabling communication between control chip U2 and the central control unit.

[0064] Capacitors C47, C46, ​​C45, C49, and C50 filter out high-frequency noise on the CAN bus, preventing it from interfering with normal signal transmission and causing signal distortion or errors, thus improving signal quality and ensuring accurate signal transmission. Diodes ZD2A, ZD2B, ZD3A, and ZD3B are clamping diodes that effectively prevent overvoltage, limiting the voltage within a safe range and protecting the transceiver chip U3 from voltage spikes, preventing damage due to overvoltage.

[0065] Please refer to Figure 3 As shown, the tire pressure signal receiving circuit further includes an IGN module. The signal input terminal of the IGN module is connected to the external vehicle ignition switch, and the signal output terminal of the IGN module is electrically connected to the MCU module. The IGN module monitors the vehicle status. When the IGN module does not receive an ignition signal, it controls the MCU module to enter a sleep state. After the IGN module receives an ignition signal, it controls the MCU module to enter the working state, reducing standby power consumption.

[0066] Specifically, the IGN module includes diode D5A, diode D5B, capacitors C9 and C2, and resistors R10, R11, R12, and R14. The power supply module outputs +3.3V to the negative terminal of diode D5B; that is, the negative terminal of diode D2B and pin 5 of the voltage regulator chip U5 are both electrically connected to the negative terminal of diode D5B. One end of resistor R11 is electrically connected to the positive terminal of the external backup power supply, and the other end of resistor R11 is electrically connected to one end of capacitor C9, one end of resistor R10, and one end of resistor R14, serving as an input terminal connected to the external vehicle ignition switch. The other end of resistor R14 is electrically connected to one end of resistor R12, one end of capacitor C20, the negative terminal of diode D5A, and the positive terminal of diode D5B, serving as an output terminal connected to the MCU module. Specifically, the other end of resistor R14 is electrically connected to pin 29 of the control chip U2.

[0067] The other end of capacitor C9, the other end of resistor R10, the other end of resistor R12, the other end of capacitor C20, and the positive terminal of diode D5A are all grounded.

[0068] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A tire pressure signal receiving circuit, characterized in that, Includes a power module, MCU module, CAN module, and RF module; The input terminal of the power module is electrically connected to an external power source, and the output terminal of the power module is electrically connected to the MCU module, CAN module, and RF module. The input terminal of the RF module is connected to an antenna ANT to receive pressure and temperature data from the sensor. The output terminal of the RF module is electrically connected to the input terminal of the MCU module, the communication interface of the MCU module is electrically connected to the CAN module, and the output terminal of the CAN module communicates with an external central control unit.

2. The tire pressure signal receiving circuit according to claim 1, characterized in that: The power module includes voltage regulator chip U1, voltage regulator chip U5, varistor ZB1, diode D1, diode D2B, diode D2A, polarized capacitor C4, polarized capacitor C6, polarized capacitor C12, capacitor C1, capacitor C2, capacitor C3, capacitor C5, capacitor C7, capacitor C8 and resistors R1 and R2. The positive terminal of the external backup power supply is electrically connected to one end of the varistor ZB1, one end of the resistor R1, the positive terminal of the diode D1, and one end of the capacitor C2. The other end of the capacitor C2 is electrically connected to one end of the capacitor C3. The negative terminal of diode D1 is electrically connected to the positive terminal of polarized capacitor C4, one end of capacitor C5, and pin 1 of voltage regulator chip U1, and is also electrically connected to an external +12V voltage. Pin 3 of voltage regulator chip U1 is electrically connected to the positive terminal of polarized capacitor C6, one end of capacitor C7, and pins 1 and 3 of voltage regulator chip U5, and outputs +5V voltage to the CAN module. Pin 5 of voltage regulator chip U5 is electrically connected to one end of capacitor C8 and the positive terminal of polarized capacitor C12. The other end of resistor R1 is electrically connected to one end of resistor R2, one end of capacitor C1, the positive terminal of diode D2B, and the negative terminal of diode D2A. The negative terminal of diode D2B and pin 5 of voltage regulator chip U5 both output +3.3V voltage to the MCU module, CAN module, and RF module. The other end of the varistor ZB1, the other end of the capacitor C3, the negative terminal of the polarized capacitor C4, the other end of the capacitor C5, the negative terminal of the polarized capacitor C6, the other end of the capacitor C7, the other end of the capacitor C8, the negative terminal of the polarized capacitor C12, the other end of the capacitor C1, the other end of the resistor R2, the positive terminal of the diode D2A, and pin 2 of the voltage regulator chip U1 and pin 2 of the voltage regulator chip U5 are all grounded.

3. The tire pressure signal receiving circuit according to claim 1, characterized in that: The MCU module includes a control chip U2, resistors R39, R41, and R42, and capacitors C36, C41, and C44. The power module outputs a +3.3V voltage to one end of resistor R41, one end of resistor R42, one end of resistor R39, one end of capacitor C44, and pins 12 and 35 of control chip U2; an external +12V voltage is input to pin 37 of control chip U2. The other end of resistor R39 is electrically connected to one end of capacitor C34 and pin 4 of control chip U2; pin 10 of control chip U2 is electrically connected to one end of capacitor C41; the other end of resistor R41 is electrically connected to pins 14 and 15 of control chip U2; and the other end of resistor R42 is electrically connected to pin 13 of control chip U2. Pins 13, 14, 16, 17, 22, 23, and 24 of the control chip U2 are all electrically connected to the output of the RF module; pins 31, 33, and 34 of the control chip U2 are all electrically connected to the CAN module. The other end of capacitor C34, the other end of capacitor C41, the other end of capacitor C44, and pins 11 and 36 of control chip U2 are all grounded.

4. The tire pressure signal receiving circuit according to claim 2, characterized in that: It also includes a clock module, which includes a crystal oscillator XT1, a resistor R34, and capacitors C35 and C36; Pin 8 of the control chip U2 is electrically connected to one end of resistor R34, one end of crystal oscillator XT1, and one end of capacitor C35. Pin 9 of the control chip U2 is electrically connected to the other end of resistor R34, the other end of crystal oscillator XT1, and one end of capacitor C36. The other ends of capacitors C35 and C36 are both grounded.

5. The tire pressure signal receiving circuit according to claim 1, characterized in that: The RT module includes an RF receiver chip U4, a crystal oscillator XT2, inductors L1, L2, L3, L4, C19, and capacitors C18, C17, C16, C15, C10, C11, C13, and C14. The power module outputs a +3.3V voltage to one end of capacitor C10, one end of capacitor C11, and pins 4 and 7 of the RF receiver chip U4; the antenna ANT is electrically connected to one end of capacitor C18 and one end of inductor C19, and the other end of inductor C19 is electrically connected to one end of capacitor C17, one end of inductor L4, one end of inductor L3, and one end of capacitor C16. The other end of inductor L3 is electrically connected to one end of capacitor C15, one end of inductor L1, and pin 2 of RF receiver chip U4; the other end of capacitor C16 is electrically connected to one end of inductor L2, the other end of inductor L1, and pin 1 of RF receiver chip U4; pin 13 of RF receiver chip U4 is electrically connected to one end of crystal oscillator XT2 and one end of capacitor C14; pin 14 of RF receiver chip U4 is electrically connected to the other end of crystal oscillator XT2 and one end of capacitor C13; pins 8, 9, 10, 11, 12, 15, and 16 of RF receiver chip U4 are all electrically connected to the signal input terminal of the MCU module. The other ends of capacitor C18, capacitor C17, inductor L4, capacitor C15, inductor L2, capacitor C10, capacitor C11, capacitor C13, capacitor C14, and pins 5, 6, and 17 of the RF receiver chip are all grounded.

6. The tire pressure signal receiving circuit according to claim 1, characterized in that: The CAN module includes a transceiver chip U3, diodes ZD2A, ZD2B, ZD3A, and ZD3B, capacitors C47, C46, ​​C45, C49, and C50, and a resistor R43. The power module outputs +3.3V voltage to one end of capacitor C47 and pin 5 of transceiver chip U3, and the power module outputs +5V voltage to pin 3 of transceiver chip U3; pins 1, 4, and 8 of transceiver chip U3 are all electrically connected to the MCU module. Pin 6 of the transceiver chip U3 is electrically connected to the negative terminal of diode ZD3A, one end of capacitor C49, and one end of resistor R43, and is connected to the CAN-L interface for communication with an external central control unit; the positive terminal of diode ZD3A is electrically connected to the positive terminal of diode ZD3B, and the other end of capacitor C49 is electrically connected to one end of capacitor C50; pin 7 of the transceiver chip U3 is electrically connected to the negative terminal of diode ZD2A, one end of capacitor C46, ​​and the other end of resistor R43, and is connected to the CAN-H interface for communication with an external central control unit; the positive terminal of diode ZD2A is electrically connected to the positive terminal of diode ZD2B, and the other end of capacitor C46 is electrically connected to one end of capacitor C45; The other ends of capacitor C47, capacitor C45, capacitor C50, the negative terminal of diode ZD2B, the negative terminal of diode ZD3B, and pin 2 of transceiver chip U3 are all grounded.

7. The tire pressure signal receiving circuit according to claim 6, characterized in that: Diodes ZD2A, ZD2B, ZD3A, and ZD3B are all Schottky diodes.

8. The tire pressure signal receiving circuit according to claim 1, characterized in that: It also includes an IGN module, whose signal input terminal is connected to the external vehicle ignition switch, and whose signal output terminal is electrically connected to the MCU module. The IGN module monitors the vehicle status.

9. The tire pressure signal receiving circuit according to claim 8, characterized in that: The IGN module includes diode D5A, diode D5B, capacitor C9, capacitor C2, and resistors R10, R11, R12, and R14. The power module outputs a +3.3V voltage to the negative terminal of diode D5B; one end of resistor R11 is electrically connected to the positive terminal of the external backup power supply, and the other end of resistor R11 is electrically connected to one end of capacitor C9, one end of resistor R10, and one end of resistor R14, and serves as an input terminal connected to the external vehicle ignition switch; the other end of resistor R14 is electrically connected to one end of resistor R12, one end of capacitor C20, the negative terminal of diode D5A, and the positive terminal of diode D5B, and serves as an output terminal connected to the MCU module. The other end of capacitor C9, the other end of resistor R10, the other end of resistor R12, the other end of capacitor C20, and the positive terminal of diode D5A are all grounded.

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