Overcurrent detection circuit and electronic device
By designing a combination of current sampling, amplification, and overcurrent detection modules, bidirectional overcurrent detection of bidirectional DC-DC circuits is achieved, overcoming the shortcomings of unidirectional detection methods in existing technologies, improving the accuracy and reliability of detection, and making it suitable for scenarios where the current direction changes frequently.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- POWEROAK INNOVATION CO
- Filing Date
- 2025-06-30
- Publication Date
- 2026-07-17
AI Technical Summary
Existing overcurrent protection circuits are mostly based on unidirectional detection, which is insufficient to meet the requirements of bidirectional current detection, especially in scenarios where the current direction changes frequently. They cannot effectively protect bidirectional, multi-channel parallel DC-DC converters.
An overcurrent detection circuit was designed. The current sampling module collects and converts the inductor current in the bidirectional DC-DC circuit, the amplifier module performs forward biasing, the overcurrent detection module performs bidirectional overcurrent detection, and outputs an overcurrent protection signal when the bidirectional overcurrent condition is met, so as to achieve accurate detection of bidirectional current.
It improves the accuracy of bidirectional current detection, ensures the reliability of overcurrent protection in scenarios with frequent changes in current direction, and protects the safety of bidirectional DC-DC circuits.
Smart Images
Figure CN224518838U_ABST
Abstract
Claims
1. An overcurrent detection circuit, characterized by comprising: The overcurrent detection circuit is connected to two bidirectional DC-DC circuits in an interleaved parallel configuration. The two bidirectional DC-DC circuits include a first DC-DC circuit and a second DC-DC circuit. The overcurrent detection circuit includes: A current sampling module is connected to the first DC-DC circuit and the second DC-DC circuit. The current sampling module is used to collect and convert the first inductor current in the first DC-DC circuit to obtain a first sampling signal, and is also used to collect and convert the second inductor current in the second DC-DC circuit to obtain a second sampling signal. The first sampling signal is a bidirectional current signal and includes a first positive current signal and a first negative current signal, and the second sampling signal is a bidirectional current signal and includes a second positive current signal and a second negative current signal. An amplification module is connected to the current sampling module. The amplification module is used to amplify and forward bias the first sampling signal to obtain a first amplified voltage signal, and is also used to amplify and forward bias the second sampling signal to obtain a second amplified voltage signal. An overcurrent detection module is connected to the amplification module. The overcurrent detection module is used to perform bidirectional overcurrent detection based on the first amplified voltage signal and the second amplified voltage signal, and output an overcurrent protection signal when the bidirectional overcurrent condition is met.
2. The overcurrent detection circuit according to claim 1, characterized by The overcurrent detection module includes: The first overcurrent detection unit is connected to the amplification module. The first overcurrent detection unit is used to perform forward overcurrent detection based on the first amplified voltage signal and the second amplified voltage signal, and output a forward overcurrent protection signal when the forward overcurrent condition is met. The second overcurrent detection unit is connected to the amplification module. The second overcurrent detection unit is used to perform reverse overcurrent detection based on the first amplified voltage signal and the second amplified voltage signal, and output a reverse overcurrent protection signal when the reverse overcurrent condition is met.
3. The overcurrent detection circuit of claim 2, wherein The first overcurrent detection unit includes: A first synthesis subunit is connected to the amplification module. The first synthesis subunit is used to synthesize a first voltage to be measured based on the first amplified voltage signal and the second amplified voltage signal. The first voltage divider unit is connected to a power supply and is used to generate a first reference voltage based on the voltage of the power supply. The first comparison subunit is connected to the first synthesis subunit and the first voltage divider subunit. The first comparison subunit is used to output the positive overcurrent protection signal when the first voltage to be measured is greater than the first reference voltage.
4. The overcurrent detection circuit according to claim 3, characterized in that, The first synthesis subunit includes resistor R3, resistor R4, diode D1, and diode D2; the first end of resistor R3 is connected to the amplification module to receive the first amplified voltage signal, the second end of resistor R3 is connected to the positive terminal of diode D1, the first end of resistor R4 is connected to the amplification module to receive the second amplified voltage signal, the second end of resistor R4 is connected to the positive terminal of diode D2, and the negative terminal of diode D1 is connected to the negative terminal of diode D2. The first voltage divider unit includes resistor R1 and resistor R2; the first end of resistor R1 is connected to the power supply, the second end of resistor R1 is connected to the first end of resistor R2, and the second end of resistor R2 is grounded. The first comparison subunit includes a comparator U1A; the non-inverting input of the comparator U1A is connected to the connection point of the resistor R1 and the resistor R2, the inverting input of the comparator U1A is connected to the negative terminals of the diode D1 and the diode D2, and the output of the comparator U1A is used to output the positive overcurrent protection signal.
5. The overcurrent detection circuit of claim 2, wherein, The second overcurrent detection unit includes: The second synthesis subunit is connected to the amplification module and the power supply. The second synthesis subunit is used to synthesize a second voltage to be measured based on the first amplified voltage signal, the second amplified voltage signal and the voltage of the power supply. The second voltage divider unit is connected to the power supply and is used to generate a second reference voltage based on the voltage of the power supply. The second comparison subunit is connected to the second synthesis subunit and the second voltage divider subunit. The second comparison subunit is used to output the reverse overcurrent protection signal when the second voltage to be measured is less than the second reference voltage.
6. The overcurrent detection circuit according to claim 5, characterized in that, The second synthesis subunit includes resistors R8, R10, and R9, diode D3, and diode D4; the first end of resistor R8 is connected to the amplification module to receive the first amplified voltage signal, the second end of resistor R8 is connected to the cathode of diode D3, the first end of resistor R10 is connected to the amplification module to receive the second amplified voltage signal, the second end of resistor R10 is connected to the cathode of diode D4, the anodes of diode D3 and diode D4 are simultaneously connected to the first end of resistor R9, and the second end of resistor R9 is connected to the power supply; The second voltage divider unit includes resistor R6 and resistor R7; the first end of resistor R6 is connected to the power supply, the second end of resistor R6 is connected to the first end of resistor R7, and the second end of resistor R7 is grounded. The second comparison subunit includes a comparator U1B; the inverting input terminal of the comparator U1B is connected to the connection point of the resistor R6 and the resistor R7, the non-inverting input terminal of the comparator U1B is connected to the positive terminals of the diode D3 and the diode D4, and the output terminal of the comparator U1B is used to output the reverse overcurrent protection signal.
7. The overcurrent detection circuit of claim 2, wherein, The overcurrent detection module further includes: A pull-up unit is connected to the first overcurrent detection unit, the second overcurrent detection unit, and the power supply. The pull-up unit is used to provide pull-up voltage for the signals output by the first overcurrent detection unit and the second overcurrent detection unit.
8. The overcurrent detection circuit of claim 1, wherein, The amplification module includes: The first amplification unit is connected to the current sampling module. The first amplification unit is used to amplify and positively bias the first positive current signal and the first negative current signal to obtain the first amplified voltage signal. The second amplification unit is connected to the current sampling module. The second amplification unit is used to amplify and positively bias the second positive current signal and the second negative current signal to obtain the second amplified voltage signal.
9. The overcurrent detection circuit of claim 1, wherein, The current sampling module includes: The first Hall element is connected in series with the inductor in the first DC-DC circuit. The first Hall element is used to collect and convert the current of the first inductor in the first DC-DC circuit to obtain the first sampling signal. The second Hall element is connected in series with the inductor in the second DC-DC circuit. The second Hall element is used to collect and convert the current of the second inductor in the second DC-DC circuit to obtain the second sampling signal.
10. An electronic device, comprising: The electronic device includes an overcurrent detection circuit as described in any one of claims 1 to 9.