Transformer area intelligent fusion terminal power supply and electric quantity detection circuit module

Abstract

The utility model discloses a transformer area intelligent fusion terminal power supply and electric quantity detection circuit module, comprising an RTC chip which is used for providing a real-time clock function and is provided with a VDD power supply pin, a GND grounding pin, an SCL / SDA communication pin and an interruption output pin; the dual-power seamless switching network comprises a first diode and a second diode, the anode of the first diode is connected with a main power supply, the anode of the second diode is connected with a standby battery, the cathodes of the first diode and the second diode converge to form an RTC power supply node, and the RTC power supply node is connected to a VDD power supply pin of the RTC chip; the power supply decoupling network comprises a first decoupling capacitor and a second decoupling capacitor which are connected in parallel between the RTC power supply node and the ground; an I2C bus interface circuit; an interrupt output circuit; a battery voltage detection network. The system provided by the utility model has the characteristics of seamless power supply switching, low-power battery monitoring, high anti-interference capability, flexibility and maintainability.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of power supply and electric quantity detection circuit module of intelligent fusion terminal in transformer area, and it is especially suitable for clock synchronization and power-down keeping application occasions of power distribution transformer area intelligent fusion terminal. BACKGROUND

[0002] Intelligent fusion terminal in transformer area undertakes electric energy data acquisition, event record, fault location, time synchronization and log evidence, and the accuracy and continuity of time stamp are extremely high.In transformer field environment, the device often faces external power supply fluctuation, instantaneous power failure, maintenance power failure and other complex working conditions, and the terminal host and communication module work in strong electromagnetic interference environment, which puts forward strict requirements on the reliability of real-time clock module.

[0003] Traditional RTC power supply scheme usually adopts single power supply or simple battery backup structure.Single power supply scheme cannot maintain RTC operation when main power is powered off, resulting in loss of time information;Although simple battery backup scheme can maintain clock operation when powered off, it often has problems such as large switching delay and voltage drop in switching moment, which may cause RTC reset or timing exception.In addition, the switching between main power and battery in traditional scheme usually depends on control logic, and when the host is reset, dead or program runs away, the switching logic may fail, causing RTC power-off risk.

[0004] In terms of battery health monitoring, there are two extreme cases in traditional scheme.One is not to set battery voltage monitoring function, which cannot be found in time when the battery is exhausted, and the time drift when powered off is not known by operation and maintenance personnel;The other is to use low resistance voltage division network for voltage sampling, which can monitor battery status, but the static current consumption of voltage division network is large, which significantly shortens the service life of battery, and is not suitable for long-term unattended transformer terminal application scene.

[0005] In terms of communication interface, I2C bus is easily disturbed in strong electromagnetic environment of transformer field, resulting in time reading and writing exception.In traditional design, bus steady-state design is often ignored, and bus level uncertainty in power-on, reset or hibernation transition state may cause false triggering or communication error.

[0006] Therefore, an RTC and battery backup power supply module capable of seamless power supply switching, low-power battery monitoring and high anti-interference capability is needed to meet the reliable clock keeping requirements of intelligent fusion terminal in transformer area in long-term unattended, complex electromagnetic environment. UTILITY MODEL CONTENT

[0007] The utility model aims at providing a kind of power supply and electric quantity detection circuit module of intelligent fusion terminal in transformer area.This module has the characteristics of seamless power supply switching, low-power battery monitoring, high anti-interference capability and flexible maintenance.

[0008] The above technical purpose of the utility model is realized through the following technical scheme:

[0009] A power supply and electric quantity detection circuit module of a district intelligent fusion terminal, comprising: an RTC chip (U17) for providing a real-time clock function, having a VDD power supply pin, a GND ground pin, a SCL / SDA communication pin and an interrupt output pin; a seamless dual-power switching network, comprising a first diode (D17) and a second diode (D18), an anode of the first diode (D17) being connected to a main power supply, an anode of the second diode (D18) being connected to a backup battery (BT1), cathodes of the first diode (D17) and the second diode (D18) converging to form an RTC power supply node, the RTC power supply node being connected to the VDD power supply pin of the RTC chip (U17); a power decoupling network, comprising a first decoupling capacitor (C78) and a second decoupling capacitor (C79) connected in parallel between the RTC power supply node and the ground; an I2C bus interface circuit, comprising a clock line pull-up resistor (R115) and a data line pull-up resistor (R116), the clock line pull-up resistor (R115) being connected between the main power supply and the SCL clock line, the data line pull-up resistor (R116) being connected between the main power supply and the SDA data line; an interrupt output circuit, comprising an interrupt pull-up resistor (R117), the interrupt pull-up resistor (R117) being connected between the main power supply and the interrupt output pin of the RTC chip (U17), the interrupt output pin being connected to a master control GPIO port; a battery voltage detection network, comprising series-connected upper and lower voltage dividing resistors (R119 and R124), one end of the upper voltage dividing resistor (R119) being connected to the backup battery (BT1), one end of the lower voltage dividing resistor (R124) being grounded, a connection midpoint of the upper voltage dividing resistor (R119) and the lower voltage dividing resistor (R124) forming a voltage sampling point, the voltage sampling point being connected to a filter capacitor (C80) and then output to a master control ADC sampling port.

[0010] The utility model further sets up: the first diode (D17) and the second diode (D18) are all Schottky diodes, and the forward voltage drop is not greater than 0.3V, guaranteeing low voltage drop loss in the power supply switching process.

[0011] The utility model further sets up: the first decoupling capacitor (C78) has a capacitance value range of 1uF to 100uF, for providing low-frequency energy reserve and energy buffer in power failure moment;The second decoupling capacitor (C79) has a capacitance value range of 10nF to 1000nF, for providing high-frequency noise bypass.

[0012] The utility model further sets up: the resistance value range of upper voltage division resistance (R119) and lower voltage division resistance (R124) all is 100kOmega-10MΩ, total voltage division resistance is not less than 200kΩ, makes the static current of battery voltage detection network is not bigger than 20muA.

[0013] The utility model further sets up: the voltage division ratio range of upper voltage division resistance (R119) and lower voltage division resistance (R124) is 1: 1-1: 3, make the voltage of voltage sampling point fall in the range of main control ADC.

[0014] The utility model further sets up: battery voltage detection network still includes configuration resistance (R152), configuration resistance (R152) is connected in series between lower voltage division resistance (R124) and ground, is used to provide configurable disconnect point and test interface of battery loop.

[0015] The utility model further sets up: the resistance value range of clock line pull-up resistance (R115), data line pull-up resistance (R116) and interrupt pull-up resistance (R117) all is 1kOmega-100kΩ, three unified resistance value configurations are adopted.

[0016] The utility model further sets up: still include mode control pull-up resistance (R118), mode control pull-up resistance (R118) is connected between main power and the mode control pin of RTC chip (U17), make mode control pin keep the logic level state determined during power on and reset.

[0017] The utility model further sets up: the capacitance range of filter capacitor (C80) is 10nF-1uF, filter capacitor (C80) and lower voltage division resistance (R124) constitute RC low pass filter network, and the cut-off frequency is not more than 10Hz, is used to filter the high frequency noise in battery voltage sampling signal.

[0018] The module adopts five area separation layout, and core clock area, bus interface area, power supply switching area, power supply stabilization area and battery monitoring area are located in the area of mutual independence, and the first decoupling capacitor (C78) and the second decoupling capacitor (C79) are arranged close to the VDD power supply pin of RTC chip (U17).

[0019] In conclusion, the utility model has the following beneficial effects:

[0020] 1. Seamless power supply switching: Through the double-diode OR-ing topology, the cathodes of the first diode (D17) and the second diode (D18) converge to form a single power supply node, realizing automatic seamless switching between the main power supply and the backup battery. When the main power supply is normally powered, the first diode (D17) is forward conducting and the second diode (D18) is reverse cut-off, and the battery is not discharged; when the main power supply is powered off, the first diode (D17) is cut off and the second diode (D18) is automatically forward conducting, and the battery takes over the power supply. The switching process is automatically completed by the forward conducting and reverse cut-off characteristics of the diodes, without the need for MCU judgment or control logic participation, and the switching time is in the order of nanoseconds to microseconds, combined with the energy buffer provided by the first decoupling capacitor (C78) at the moment of power failure, to ensure that the RTC power supply voltage does not drop to cause reset risk, realizing the continuity of power failure timing.

[0021] 2. Low-power battery monitoring: The battery voltage detection network uses high-resistance voltage division configuration, with the resistance range of the upper voltage dividing resistor (R119) and the lower voltage dividing resistor (R124) being 100kΩ to 10MΩ. With a typical 1MΩ+1MΩ configuration, the total voltage dividing resistor reaches 2MΩ, and the static current is only 1.8μA, which is much lower than the self-discharge current of the battery, and the consumption of the battery life can be ignored.

[0022] 3. High anti-interference capability: The power supply decoupling network uses the parallel configuration of the first decoupling capacitor (C78) and the second decoupling capacitor (C79), the first decoupling capacitor (C78) provides low-frequency energy storage and energy buffer at the moment of power failure, and the second decoupling capacitor (C79) provides high-frequency noise bypass, both of which cover the wide frequency domain decoupling demand in parallel, effectively suppressing the influence of power supply noise on the frequency stability of the RTC crystal oscillator. The I2C bus pull-up resistor uses a resistance range of 1kΩ to 100kΩ, achieving a balance between anti-interference capability and power consumption, and ensuring communication reliability in strong electromagnetic environment in the field. The filter capacitor (C80) and the lower voltage dividing resistor (R124) form an RC low-pass filter network with a cutoff frequency not greater than 10Hz, which can effectively filter out 50Hz power frequency interference and higher frequency electromagnetic noise, improving the stability of battery voltage sampling.

[0023] 4. Steady-state design reliability: The interrupt pull-up resistor (R117) ensures that the interrupt output pin remains stable at a high level when the RTC does not trigger an interrupt, avoiding false triggering caused by noise coupling; the clock line pull-up resistor (R115) and the data line pull-up resistor (R116) ensure the steady-state level of the I2C bus under the open-drain structure; the mode control pull-up resistor (R118) keeps the mode control pin of the RTC chip (U17) at a certain logic level state during power-on and reset, avoiding the chip from entering an unintended working mode. This collaborative configuration enables the RTC to serve as a periodic wake-up source for the master low-power sleep, supporting the low-power operation strategy of the transformer area terminal, while ensuring the determinacy of system behavior in transition states such as power-on, reset, and sleep.

[0024] 5. Flexible maintainability: The configuration resistor (R152) is connected in series between the lower voltage dividing resistor (R124) and the ground, providing a configurable disconnection point and test interface for the battery loop. During the production stage, the configuration resistor (R152) can be replaced by a current measurement resistor to monitor the battery loop current; during the maintenance stage, the battery loop can be isolated for fault diagnosis by disconnecting the configuration resistor (R152). The master can monitor the battery voltage status in real time by periodically reading the ADC sample value of the voltage sampling point, and generate a low voltage warning when the battery voltage is below the preset threshold, reminding the maintenance personnel to replace the battery in advance, avoiding power-down time drift after the battery is depleted, and reducing the test and maintenance costs at each stage of the product life cycle.

[0025] 6. Structural optimization design: The module adopts a five-zone separated layout, with the core clock zone, bus interface zone, power supply switching zone, power supply stabilization zone, and battery monitoring zone located in independent areas, improving the isolation and anti-interference capability between the functional zones. The first decoupling capacitor (C78) and the second decoupling capacitor (C79) are arranged close to the VDD power supply pin of the RTC chip (U17), shortening the high-frequency loop area and improving the decoupling effect. The clock line pull-up resistor (R115), the data line pull-up resistor (R116), and the interrupt pull-up resistor (R117) are configured with uniform resistance values, facilitating material management and spatial layout optimization, allowing them to be arranged centrally on the PCB, shortening the wiring length, and reducing the risk of crosstalk between the wires. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the overall circuit structure schematic diagram of the utility model. DETAILED DESCRIPTION

[0027] The utility model will be further explained in detail in combination with the drawings.

[0028] As Figure 1As shown, the intelligent fusion terminal power supply and electric quantity detection circuit module provided by the utility model has a modular circuit layout structure as a whole, and presents signal and power flow distribution from left to right. The module is divided into five functional areas in space: a core clock area, a bus interface area, a power supply switching area, a power supply stabilization area and a battery monitoring area. The areas are sequentially connected through electrical nodes, and constitute a complete functional link.

[0029] The RTC chip (U17) adopts RX8025T model, and is arranged at the center position of the core clock area as the core clock element of the module. The RTC chip (U17) has a VDD power supply pin, a GND ground pin, an SCL / SDA communication pin, an INTA / INTB interrupt output pin and a POE mode control pin. The VDD power supply pin is configured close to other decoupling capacitors, the SCL / SDA communication pin forms a bus interface area with other pull-up resistors, and the INTA / INTB interrupt pin is independently led out to the GPIO port of the external master. The standby power consumption of the RX8025T chip is typically 0.25 μA, supports I2C standard mode (100 kHz) and fast mode (400 kHz), has a built-in crystal oscillator and temperature compensation function, and has high timing accuracy.

[0030] The dual-power seamless switching network adopts a double-diode parallel convergence structure, and is arranged in the power supply switching area. The anode of the first diode (D17) is connected to the main power supply VCC 3V3, and the anode of the second diode (D18) is connected to the backup battery (BT1). The cathodes of the first diode (D17) and the second diode (D18) converge at the same electrical node in space, forming an RTC power supply node. The RTC power supply node is directly connected to the VDD power supply pin of the RTC chip (U17), and simultaneously serves as the common connection point of the first decoupling capacitor (C78) and the second decoupling capacitor (C79).

[0031] The first diode (D17) and the second diode (D18) both adopt LLSD103A Schottky diodes, and the typical value of the forward voltage drop thereof is 0.2V to 0.3V, which ensures low voltage drop loss in the power supply switching process. Compared with ordinary silicon diodes, Schottky diodes have lower forward voltage drop and faster switching speed, which is beneficial to improve the power supply efficiency and switching response speed.

[0032] The working principle of the dual power seamless switching network is as follows: when the main power supply VCC 3V3 normally supplies power, the main power supply voltage (typical value 3.3V) is higher than the backup battery (BT1) voltage (typical value 3.6V minus the forward voltage drop of the second diode (D18)), the first diode (D17) is forward conducting, the second diode (D18) is reverse cut-off because the cathode voltage is higher than the anode voltage, and the backup battery (BT1) is not discharged. When the main power supply is powered off, the RTC power supply node voltage decreases, the first diode (D17) is cut off, the second diode (D18) is forward conducting, and the backup battery (BT1) automatically takes over the power supply. The switching process is automatically completed by the forward conduction and reverse cut-off characteristics of the diodes, without the need for MCU judgment or control logic participation, and the switching time depends on the switching characteristics of the diodes, generally in the order of nanoseconds to microseconds.

[0033] The power decoupling network is arranged in the power stabilization area, including a first decoupling capacitor (C78) and a second decoupling capacitor (C79) connected in parallel between the RTC power supply node and the ground. The first decoupling capacitor (C78) is a 10μF ceramic capacitor, used to provide low-frequency energy storage and energy buffer at power-off instant; the second decoupling capacitor (C79) is a 100nF ceramic capacitor, used to provide high-frequency noise bypass. The two capacitors in parallel cover the decoupling requirements in a wide frequency domain, the second decoupling capacitor (C79) provides a bypass path for MHz-level high-frequency noise, and the first decoupling capacitor (C78) provides energy support for kHz-level low-frequency fluctuations.

[0034] The first decoupling capacitor (C78) releases stored energy at power-off instant, providing energy buffer for the switching process. Based on the estimation of the first decoupling capacitor (C78) with a capacitance of 10μF and a typical RTC working current of 1μA, the first decoupling capacitor (C78) can maintain power supply for milliseconds at the switching instant, far exceeding the diode switching time, ensuring that the RTC power supply voltage does not drop to cause reset risk. The first decoupling capacitor (C78) and the second decoupling capacitor (C79) are arranged close to the VDD power supply pin of the RTC chip (U17), shortening the high-frequency loop area and improving the decoupling effect, further reducing the radiation risk.

[0035] The I2C bus interface circuit is arranged in the bus interface area, including a clock line pull-up resistor (R115) and a data line pull-up resistor (R116). One end of the clock line pull-up resistor (R115) is connected to the main power supply VCC 3V3, and the other end is connected to the SCL clock line (RTC_TWI1_SCK); one end of the data line pull-up resistor (R116) is connected to the main power supply VCC 3V3, and the other end is connected to the SDA data line (RTC_TWI1_SDA). The clock line pull-up resistor (R115) and the data line pull-up resistor (R116) both have a resistance of 10kΩ, and the two resistors are arranged in parallel in space between the bus and the power supply.

[0036] The I2C bus adopts an open-drain structure and must be configured with a pull-up resistor to work. Too small resistance value will increase the driving power consumption and EMI risk, and too large resistance value will reduce the anti-interference ability of the bus, making it more susceptible to noise in a strong electromagnetic environment. A 10kΩ pull-up resistor can meet the rising time requirements of the bus specification in both I2C standard mode (100kHz) and fast mode (400kHz).

[0037] The interrupt output circuit is arranged in the bus interface area and includes an interrupt pull-up resistor (R117). One end of the interrupt pull-up resistor (R117) is connected to the main power supply VCC 3V3, and the other end is connected to the interrupt output pin INTA of the RTC chip (U17). The interrupt output pin is connected to the GPIO port of the external host through the signal line (H20_GPIO_RTC_INT). The interrupt pull-up resistor (R117) has a resistance value of 10kΩ and forms a unified pull-up resistor group with the clock line pull-up resistor (R115) and the data line pull-up resistor (R116), facilitating spatial concentration arrangement and parameter consistency management.

[0038] The configuration of the interrupt pull-up resistor (R117) ensures that the interrupt output pin maintains a stable high level when the RTC does not trigger an interrupt. The interrupt output of the RTC chip (U17) is usually configured in an open-drain or push-pull structure. After configuring the pull-up resistor, the interrupt line can maintain a stable default high level regardless of the chip output structure, avoiding false triggering caused by the suspended state. When a preset event occurs inside the RTC (alarm trigger, second pulse, battery event, etc.), the INTA pin outputs a low-level pulse or a continuous low level, notifying the host to respond and process. This allows the host to enter a low-power sleep mode without continuous polling of the RTC state, meeting the demand for long-term online but low-power operation of the transformer area terminal.

[0039] The mode control pull-up resistor (R118) is connected between the main power supply VCC 3V3 and the mode control pin POE of the RTC chip (U17). The mode control pull-up resistor (R118) has a resistance value of 10kΩ, which keeps the mode control pin in a determined logic high state during power-on and reset. This processing avoids the uncertain state caused by the suspended functional pin, preventing the chip from entering an unintended working mode or generating additional power consumption. For other unused pins (FOUT / TEST / NC, etc.) of the RTC chip (U17), fixed connection or grounding processing is performed to avoid power consumption anomalies and signal interference caused by noise coupling of suspended pins.

[0040] The battery voltage detection network is arranged in the battery monitoring area, and adopts a combined structure of series voltage division and parallel filtering. One end of an upper voltage division resistor (R119) is connected to a positive electrode of a backup battery (BT1), and the other end is connected to a voltage division midpoint; one end of a lower voltage division resistor (R124) is connected to the voltage division midpoint, and the other end is connected to the ground through a configuration resistor (R152). The voltage division midpoint forms a voltage sampling point, and a signal line RTC_BAT_AD is led out. One end of a filtering capacitor (C80) is connected to the voltage sampling point, and the other end is grounded, and the voltage sampling point is output to a main control ADC sampling port through a signal line.

[0041] The upper voltage division resistor (R119) and the lower voltage division resistor (R124) both adopt a resistance value of 1MΩ, and the total voltage division resistance reaches 2MΩ. According to the calculation of a typical 3.6V lithium battery voltage, the static current of the voltage division network is only 1.8μA, which is much lower than the self-discharge current of the battery, and the influence on the battery life can be ignored. The high resistance value design is for the long-term unattended scene. The 1:1 voltage division ratio makes the voltage of the voltage sampling point half of the voltage of the backup battery (BT1), and the typical value is about 1.8V, which falls within the 3.3V range of the main control ADC, which not only ensures the safety of sampling, but also provides enough resolution space.

[0042] The filtering capacitor (C80) adopts a capacitance value of 100nF, and forms an RC low-pass filter network with the lower voltage division resistor (R124). According to the calculation of the resistance value 1MΩ of the lower voltage division resistor (R124) and the capacitance value 100nF of the filtering capacitor (C80), the cutoff frequency is about 1.6Hz, which can effectively filter out 50Hz power frequency interference and electromagnetic noise of higher frequency, while retaining the direct current component of the slow change of the battery voltage. The filtering parameter is suitable for the slow change characteristic of the battery voltage, and the sampling response speed and the noise suppression capability reach a balanced state.

[0043] The configuration resistor (R152) adopts a resistance value of 0Ω, and is connected in series between the lower voltage division resistor (R124) and the ground, providing a configurable disconnect point and a test interface for the battery circuit. During the production stage, the configuration resistor (R152) can be replaced by a current measurement resistor to monitor the battery circuit current; during the maintenance stage, the battery circuit can be isolated for fault diagnosis by disconnecting the configuration resistor (R152); different battery schemes (with / without battery, different sampling strategies) can be quickly switched through the configuration resistor (R152).

[0044] The backup battery (BT1) adopts an LS14250 type disposable lithium battery, with a typical voltage of 3.6V and a capacity of 1200mAh, providing energy for the RTC power failure retention. With the high resistance voltage division network, the total power consumption of the entire module in the battery powered state can be controlled within 3μA. According to the calculation, the 1200mAh battery can support the continuous operation of the RTC for 400,000 hours, which is much longer than the chemical life of the battery itself.

[0045] In the normal power supply working state, the main power supply VCC 3V3 supplies power to the RTC power supply node through the first diode (D17), and the RTC chip (U17) works normally. The second diode (D18) is reverse blocked, and the backup battery (BT1) is not discharged. The main control reads / writes time, sets the alarm clock through the I2C bus (SCL / SDA). The RTC chip (U17) generates an interrupt according to the setting, and reminds the main control to execute periodic tasks (such as hour event, time request, log segmentation, etc.) through the interrupt output pin INTA and the signal line PH20_GPIO_RTC_INT. The main control periodically reads the ADC sampling value of the voltage sampling point RTC_BAT_AD, and evaluates the battery health (low voltage warning, life prediction).

[0046] In the power failure retention working state, the main power supply VCC 3V3 fails, the first diode (D17) is cut off, and the backup battery (BT1) supplies power to the RTC power supply node through the second diode (D18). The first decoupling capacitor (C78) provides short-time energy buffer at the power failure moment, so as to ensure that VDD does not drop to cause RTC reset during the switching process. The RTC chip (U17) continues to time, and guarantees the continuity of the event time stamp of the transformer area terminal. After the main control is powered on again, the RTC time is read through I2C, and whether it is reliably retained during power failure is judged combined with the battery voltage, and if necessary, reporting or re-time setting is triggered.

[0047] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solution falling within the idea of the present application belongs to the protection scope of the present application. It should be noted that for ordinary skilled persons in the technical field, some improvements and decorations without departing from the principle of the present application are also considered as the protection scope of the present application.

Claims

1. A power supply and power detection circuit module for a transformer area intelligent fusion terminal, characterized in that, Comprise: RTC chip (U17) for providing real-time clock function, with VDD power supply pin, GND ground pin, SCL / SDA communication pin and interrupt output pin; Dual power seamless switching network, including first diode (D17) and second diode (D18), the anode of the first diode (D17) is connected to the main power supply, the anode of the second diode (D18) is connected to the standby battery (BT1), the cathodes of the first diode (D17) and the second diode (D18) are converged to form an RTC power supply node, and the RTC power supply node is connected to the VDD power supply pin of the RTC chip (U17); Power decoupling network, including first decoupling capacitor (C78) and second decoupling capacitor (C79) connected in parallel between the RTC power supply node and the ground; I2C bus interface circuit, including clock line pull-up resistor (R115) and data line pull-up resistor (R116), the clock line pull-up resistor (R115) is connected between the main power supply and the SCL clock line, and the data line pull-up resistor (R116) is connected between the main power supply and the SDA data line; Interrupt output circuit, including interrupt pull-up resistor (R117), the interrupt pull-up resistor (R117) is connected between the main power supply and the interrupt output pin of the RTC chip (U17), and the interrupt output pin is connected to the master GPIO port; Battery voltage detection network, including series-connected upper voltage dividing resistor (R119) and lower voltage dividing resistor (R124), one end of the upper voltage dividing resistor (R119) is connected to the standby battery (BT1), one end of the lower voltage dividing resistor (R124) is grounded, a voltage sampling point is formed at the connection point of the upper voltage dividing resistor (R119) and the lower voltage dividing resistor (R124), and the voltage sampling point is connected to a filter capacitor (C80) and then output to the master ADC sampling port.

2. The transformer area intelligent fusion terminal power supply and electric quantity detection circuit module according to claim 1, characterized in that, The first diode (D17) and the second diode (D18) are both Schottky diodes, and the forward voltage drop is not greater than 0.3V, which ensures low voltage drop loss in the power supply switching process. 3.The intelligent terminal power supply and power detection circuit module of a transformer area according to claim 1, characterized in that, The capacitance value of the first decoupling capacitor (C78) ranges from 1μF to 100μF, which is used to provide low-frequency energy storage and energy buffer in power-off instant; the capacitance value of the second decoupling capacitor (C79) ranges from 10nF to 1000nF, which is used to provide high-frequency noise bypass.

4. The transformer area intelligent fusion terminal power supply and electric quantity detection circuit module according to claim 1, characterized in that, The resistance value of the upper voltage dividing resistor (R119) and the lower voltage dividing resistor (R124) ranges from 100kΩ to 10MΩ, and the total voltage dividing resistance is not less than 200kΩ, so that the static current of the battery voltage detection network is not greater than 20μA.

5. The transformer area intelligent fusion terminal power supply and electric quantity detection circuit module according to claim 1, characterized in that, The voltage dividing ratio of the upper voltage dividing resistor (R119) to the lower voltage dividing resistor (R124) ranges from 1:1 to 1:3, so that the voltage of the voltage sampling point falls within the range of the master ADC.

6. The transformer area intelligent fusion terminal power supply and electric quantity detection circuit module according to claim 1, characterized in that, The battery voltage detection network further comprises a configuration resistor (R152) connected in series between the lower voltage dividing resistor (R124) and the ground, which is used to provide a configurable disconnection point and a test interface for the battery circuit.

7. The transformer area intelligent fusion terminal power supply and electric quantity detection circuit module according to claim 1, characterized in that, The resistance value range of the clock line pull-up resistor (R115), the data line pull-up resistor (R116) and the interrupt pull-up resistor (R117) is 1kΩ-100kΩ, and the three adopt unified resistance value configuration.

8. The transformer area intelligent fusion terminal power supply and electric quantity detection circuit module according to claim 1, characterized in that, A mode control pull-up resistor (R118) is further included, which is connected between the main power supply and the mode control pin of the RTC chip (U17), so that the mode control pin maintains a determined logic level state during power-on and reset.

9. The terminal power supply and electric quantity detection circuit module of the transformer area intelligent fusion terminal according to claim 1, characterized in that, The capacitance value range of the filter capacitor (C80) is 10nF to 1μF, and the filter capacitor (C80) and the lower voltage dividing resistor (R124) constitute an RC low-pass filter network, and the cut-off frequency is not greater than 10Hz, which is used for filtering high-frequency noise in the battery voltage sampling signal.

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