Battery removal detection circuit and detection method thereof

Abstract

The present invention discloses a battery removal detection circuit and a detection method thereof, and relates to the field of integrated circuits. The battery removal detection circuit includes a chip circuit and a power supply circuit connected to the chip circuit. The chip circuit includes a comparator connected to the power supply circuit, and the comparator is also connected to a reference voltage. The comparator compares the reference voltage and the sampling voltage of the power supply circuit, and outputs the comparison result to a processor; the power supply circuit includes a power supply for supplying power to the chip circuit, and the power supply is connected to the chip circuit through a battery detection terminal; the power supply circuit also includes a diode, one end of the diode is connected to the power supply, and the other end supplies power to the chip circuit through a chip power supply terminal. The diode is connected to one end of the chip circuit and is also connected to a capacitor, and the other end of the capacitor is grounded. The technical solution of the present invention continues to supply power to the chip circuit through the capacitor after power failure, so that the chip circuit can send a detection signal in time to close the circuit in advance.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a battery removal detection circuit and a detection method thereof. Background Art

[0002] Battery management is an indispensable technology in battery applications. In cellular-based narrowband Internet of Things (NB-loT) applications, the battery is the energy source component of the cellular-based wireless terminal. In the daily use of mobile terminals, it is inevitable to encounter illegal battery removal. In order to avoid permanent damage to the power supply of the wireless terminal due to illegal removal, it is necessary to detect whether the battery has been removed during use. If the battery is removed suddenly, it is necessary to quickly send a battery removal detection signal to the terminal connection port to indicate that the wireless terminal may lose power quickly before the battery is removed, so as to prompt the wireless terminal to shut down in time. Summary of the invention

[0003] The main purpose of the present invention is to provide a battery removal detection circuit and a detection method thereof, so that the circuit can send a detection signal in time after the battery is removed.

[0004] To achieve the above object, the present invention provides a battery removal detection circuit, comprising a chip circuit and a power supply circuit connected to the chip circuit, wherein the chip circuit comprises a comparator connected to the power supply circuit, the comparator is also connected to a reference voltage, the comparator compares the reference voltage and a sampled voltage of the power supply circuit, and outputs the comparison result to a processor;

[0005] The power supply circuit includes a power supply for supplying power to the chip circuit, and the power supply is connected to the chip circuit through a battery detection terminal; the power supply circuit also includes a diode, one end of which is connected to the power supply, and the other end supplies power to the chip circuit through a chip power supply terminal. One end of the diode connected to the chip circuit is also connected to a capacitor, and the other end of the capacitor is grounded.

[0006] Preferably, the chip circuit further includes a sampling resistor, which includes a first resistor and a second resistor connected in series, wherein one end of the first resistor is connected to the battery detection end, and the other end is respectively connected to the comparator and the second resistor.

[0007] Preferably, the chip circuit further includes an enable controller, which is connected to the second resistor and the comparator respectively, and is used to adjust the duty cycle to control the power consumption of the chip circuit.

[0008] Preferably, the first resistor, the second resistor and the enable controller are connected in series in sequence, and one end of the second resistor is connected to the enable controller and is grounded.

[0009] Preferably, the diode is a Schottky diode.

[0010] Preferably, the capacitor is a supercapacitor.

[0011] The present invention also provides a battery removal detection method, comprising the following steps:

[0012] The power supply supplies power to the chip circuit through the chip power supply terminal;

[0013] The battery detection end inputs the power supply to the chip circuit to obtain a sampling voltage, and inputs the obtained sampling voltage to the comparator for comparison with the reference voltage;

[0014] When the sampling voltage is equal to the reference voltage, the comparator outputs a comparison signal to the chip processor to determine that the power supply is normally supplying power to the chip circuit;

[0015] When the sampled voltage is less than the reference voltage, the comparator outputs a comparison signal to the chip processor to determine that the power supply has been removed. At this time, the capacitor connected to the chip power supply terminal supplies power to the chip circuit.

[0016] Preferably, the value of the reference voltage is preset so that the reference voltage is equal to the sampling voltage during normal operation.

[0017] Preferably, an enable controller connected to the comparator sends an enable signal to the comparator for adjusting the duty cycle to control the power consumption of the chip circuit.

[0018] The technical solution of the present invention continues to supply power to the chip circuit after power failure through a capacitor connected in parallel with the power supply. The chip power supply end can still maintain an effective voltage for a considerable period of time, so that the chip circuit can send a detection signal in time, shut down the circuit in advance, and avoid damage to the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the circuit principle of the battery removal detection circuit of the present invention;

[0020] Figure 2 FIG. 4 is a flow chart of a battery removal detection method according to the present invention.

[0021] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0023] The present invention is further described below in conjunction with the accompanying drawings.

[0024] like Figure 1 As shown, an embodiment of the present invention provides a battery removal detection circuit, including a chip circuit and a power supply circuit connected to the chip circuit, the chip circuit includes a comparator P1 connected to the power supply circuit, and the comparator P1 is also connected to a reference voltage V BG , the comparator P1 compares the reference voltage V BG And the sampling voltage V of the power supply circuit SAM and output the comparison result to a processor (not shown);

[0025] The power supply circuit includes a power supply V for supplying power to the chip circuit. BAT , the power supply V BAT The battery detection terminal A is connected to the chip circuit; the power supply circuit also includes a diode D1, one end of which is connected to the power supply V BAT , and the other end supplies power to the chip circuit through the chip power supply terminal B. The diode D1 is connected to one end of the chip circuit and is also connected to a capacitor C1, and the other end of the capacitor C1 is grounded.

[0026] The working principle of the battery removal detection circuit of the present invention is: power supply VBAT The chip circuit is powered by a series diode D1 and a parallel capacitor C1. The battery detection terminal A is directly connected to the power supply V BAT And chip circuit connection; battery detection terminal A connects the power supply V BAT Input to the chip circuit to obtain the sampling voltage V SAM , the obtained sampling voltage V SAM Input to comparator P1 and reference voltage V BG For comparison; during normal operation, the sampling voltage V SAM is equal to the reference voltage V BG ; When the power supply V BAT When the battery is disconnected (the battery is removed), the battery detection terminal A will lose power immediately, that is, the sampling voltage V SAM will immediately become zero, however, due to the voltage stabilization effect of capacitor C1, the chip power supply terminal B can still maintain an effective voltage for a considerable period of time. The chip circuit provides power V BAT The voltage sends a detection signal to the processor in time during this period of time, so that the processor can shut down in advance.

[0027] Preferably, the chip circuit further includes a sampling resistor, which includes a first resistor R1 and a second resistor R2 connected in series, wherein one end of the first resistor R1 is connected to the battery detection terminal A, and the other end is respectively connected to the comparator P1 and the second resistor R2.

[0028] Preferably, the chip circuit further includes an enable controller S1, which is connected to the second resistor R2 and the comparator P1 respectively, and is used to adjust the duty cycle to control the power consumption of the chip circuit. The power consumption of the chip circuit is reduced so that after the battery is removed, the required power consumption can support the chip circuit to send a detection signal to the processor, and the processor can be shut down in time.

[0029] Preferably, the first resistor R1, the second resistor R2 and the enable controller S1 are connected in series in sequence, and one end of the second resistor R2 is connected to the enable controller S1 and is grounded.

[0030] Preferably, the diode D1 is a Schottky diode D1. Using the Schottky diode D1 as a switch tube can increase the switching speed of the switch tube.

[0031] Preferably, the capacitor C1 is a supercapacitor, which can store more electrical energy, so as to facilitate supporting the chip circuit to complete subsequent detection work.

[0032] like Figure 2 As shown, the present invention also provides a battery removal detection method, comprising the following steps:

[0033] Power supply V BAT Power the chip circuit through the chip power supply terminal B;

[0034] Battery detection terminal A connects the power supply V BAT Input to the chip circuit to obtain the sampling voltage V SAM , the obtained sampling voltage V SAM Input to comparator P1 and reference voltage V BG Make comparisons;

[0035] When the sampling voltage V SAM is equal to the reference voltage V BG When the comparator P1 outputs a comparison signal to the chip processor, the power supply V BAT Provide normal power supply for chip circuit;

[0036] When the sampling voltage V SAM is less than the reference voltage V BG When the comparator P1 outputs a comparison signal to the chip processor, the power supply V BAT has been removed, at this time, the capacitor C1 connected to the chip power supply terminal B provides power for the chip circuit.

[0037] Preferably, the reference voltage V is preset BG value so that the reference voltage V BG Equal to the sampling voltage V during normal operation SAM .

[0038] Specifically, the reference voltage V BG The calculation is done by the following equation:

[0039] V SAM / R 2 =V DET / (R 1 +R 2 )

[0040] V BG = V SAM = V DET *R 2 / (R 1 +R 2 )

[0041] Among them, V SAM is the sampling voltage, V DET is the voltage of the battery detection terminal A, V BG is the reference voltage.

[0042] Preferably, an enable controller S1 connected to the comparator P1 sends an enable signal to the comparator P1 for adjusting the duty cycle to control the power consumption of the chip circuit.

[0043] It should be understood that the above are only preferred embodiments of the present invention, and the patent scope of the present invention cannot be limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A battery removal detection circuit, characterized in that: The chip circuit includes a chip circuit and a power supply circuit connected to the chip circuit, wherein the chip circuit includes a comparator connected to the power supply circuit, the comparator is also connected to a reference voltage, and the comparator compares the reference voltage and the sampled voltage of the power supply circuit and outputs the comparison result to a processor; The power supply circuit includes a power supply for supplying power to the chip circuit, the power supply is connected to the chip circuit via a battery detection terminal, and the battery detection terminal is directly connected to the power supply and the chip circuit; the power supply circuit also includes a diode, one end of the diode is connected to the power supply, and the other end supplies power to the chip circuit via a chip power supply terminal, the end of the diode connected to the chip circuit is also connected to a capacitor, and the other end of the capacitor is grounded; The chip circuit also includes a sampling resistor, which includes a first resistor and a second resistor connected in series, one end of the first resistor is connected to the battery detection end, and the other end is respectively connected to the comparator and the second resistor; The chip circuit further includes an enable controller, which is connected to the second resistor and the comparator respectively, and is used to adjust the duty cycle to control the power consumption of the chip circuit.

2. The battery removal detection circuit according to claim 1, characterized in that: The first resistor, the second resistor and the enable controller are connected in series in sequence, and one end of the second resistor is connected to the enable controller and is grounded.

3. The battery removal detection circuit according to claim 1, characterized in that: The diode is a Schottky diode.

4. The battery removal detection circuit according to claim 1, characterized in that: The capacitor is a supercapacitor.

5. A battery removal detection method, characterized in that: The battery removal detection circuit as claimed in any one of claims 1 to 4 comprises the following steps: The power supply supplies power to the chip circuit through the chip power supply terminal; The battery detection end inputs the power supply to the chip circuit to obtain a sampling voltage, and inputs the obtained sampling voltage to the comparator for comparison with the reference voltage; When the sampling voltage is equal to the reference voltage, the comparator outputs a comparison signal to the chip processor to determine that the power supply is normally supplying power to the chip circuit; When the sampled voltage is less than the reference voltage, the comparator outputs a comparison signal to the chip processor to determine that the power supply has been removed. At this time, the capacitor connected to the chip power supply terminal supplies power to the chip circuit; An enable controller connected to the comparator sends an enable signal to the comparator for adjusting the duty cycle to control the power consumption of the chip circuit.

6. The battery removal detection method according to claim 5, characterized in that: The value of the reference voltage is preset so that the reference voltage is equal to the sampling voltage during normal operation.

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