Patent ID: 9742399
Date: 2017-08-22
CPC Classifications: H02J,H03F,H03K,H04R

Claim:
1. An apparatus for controlling spike voltage in a switching output stage, comprising: the switching output stage configured to receive an input signal and provide a responsive output signal between a first supply voltage and a second supply voltage, the switching output stage having a first switching device and a second switching device with a common output node; the first switching device being coupled to the first supply voltage and the common output node, and the second switching device being coupled to the second supply voltage and the common output node, the first supply voltage being higher than the second supply voltage; and a pulling circuit coupled to one of the first switching device and the second switching device, the pulling circuit configured to pull a control voltage of one of the first switching device and the second switching device to reduce impedance of the one of the first switching device and the second switching device in response to a determination that the output signal at the common output node is either larger than a first predetermined threshold, which is close to the first supply, or lower than a second predetermined threshold, which is close to the second supply; wherein a pulling strength of the pulling circuit increases as output voltage increases in response to the output voltage being larger than the first predetermined threshold, and the pulling strength of the pulling circuit increases as output voltage decreases in response to the output voltage being lower than the second predetermined threshold.