| 摘要 |
A circuit for sensing the voltage across a power device, such as an insulated gate bipolar transistor (IGBT), that provides a power signal, such as to a motor. Where power devices are connected in a half bridge configuration, the sensing circuitry provides low side and high side sense signals. The signals indicate respectively when voltage changes across the low side and high side power devices. If on times of the devices are separated by deadtime, one sense signal can indicate the beginning of deadtime and the other can indicate the ending of the deadtime. The sensing circuitry can provide a sense result signal indicating whether voltage across the power device is greater than a reference voltage. The sense result signal can be received both by feedback signal circuitry that provides a signal indicating when voltage changes and also by shutdown circuitry that causes driving circuitry to turn off the power device if it is turned on when voltage across it is greater than the reference voltage, which occurs in a short circuit condition. The circuitry can be combined in an integrated circuit in which low side and high side sense signals are used both to provide voltage feedback signals and also to turn off the low or high side device if it is on when the voltage across it exceeds its reference voltage.
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