US 12,405,318 B2
Method and apparatus for fast short circuit detection of a short circuit at a gate-controlled power switch
Aly Mashaly, Kyoto (JP); Ignacio Lizama, Kyoto (JP); and Vikneswaran Thayumanasamy, Kyoto (JP)
Assigned to Rohm Co., Ltd., Kyoto (JP)
Filed by ROHM CO., LTD., Kyoto (JP)
Filed on Sep. 28, 2023, as Appl. No. 18/476,574.
Application 18/476,574 is a continuation of application No. PCT/IB2021/052690, filed on Mar. 31, 2021.
Prior Publication US 2024/0019501 A1, Jan. 18, 2024
Int. Cl. G01R 31/52 (2020.01); G01R 15/04 (2006.01); G01R 19/00 (2006.01); H03K 17/082 (2006.01)
CPC G01R 31/52 (2020.01) [G01R 15/04 (2013.01); G01R 19/0038 (2013.01); H03K 17/0822 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A short circuit detection apparatus used for short circuit detection at a gate-controlled power switch,
said apparatus comprising
a measurement circuit adapted to generate a measurement signal in response to a voltage drop along a stray inductance of the gate-controlled power switch and
a short circuit detection signal generation circuit adapted to generate a short circuit detection signal if the measurement signal exceeds a reference voltage and the gate-controlled power switch is in a switched-on state,
wherein the short circuit detection signal generation circuit comprises a comparator circuit which is adapted to compare a measurement signal generated by the measurement circuit with the reference voltage to generate a comparator output signal and an enabling short circuit detection circuit having:
a voltage divider circuit adapted to measure an output voltage of a gate control signal output by a gate driver circuit and supplied to a gate terminal of the gate-controlled power switch to provide a measured gate voltage,
a signal delay circuit adapted to delay the measured gate voltage with a delay time to provide a short circuit detection enable signal, and having
a logic gate wherein the comparator output signal output by the comparator circuit is supplied via the logic gate as the short circuit detection signal to an input of the gate driver circuit if the logic gate is enabled by the short circuit detection enable signal received from the signal delay circuit.