DRIVE CONTROL CIRCUIT, AND IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

A drive control circuit includes: a first protection circuit connected between a signal input line and a ground line and clamps a voltage of AC noise superimposed on the signal input line at one clamp level; a second protection circuit connected between the signal input line and the ground line and clamps the voltage of the AC noise superimposed on the signal input line at an other clamp level Vn; and a drive signal generation circuit generating the drive signal based on a comparison between a voltage in the signal input line and Vt. The input signal has binary levels including an L-level voltage VL and an H-level voltage VH, and a mean voltage of the AC noise is lower than a differential voltage between Vt and VL and higher than a differential voltage between Vt and VH.

主权项

1. A drive control circuit that generates a drive signal for a switching element applying or interrupting current flow in a load in response to an input signal, comprising:
a first protection circuit that is connected between a signal input line for the input signal and a ground line, and clamps a voltage of an AC noise superimposed on the signal input line at one clamp level; a second protection circuit that is connected between the signal input line and the ground line, and clamps the voltage of the AC noise superimposed on the signal input line at another clamp level Vn; and a drive signal generation circuit that generates the drive signal based on a comparison between a voltage in the signal input line and a threshold value, wherein: the input signal has binary levels including an L-level voltage and an H-level voltage; and the one clamp level and the other clamp level are set such that a mean voltage of the AC noise clamped at the one clamp level and the other clamp level is lower than a differential voltage between the threshold voltage and the L-level voltage and higher than a differential voltage between the threshold voltage and the H-level voltage; wherein the one clamp level is smaller than zero; and wherein the other clamp level is larger than zero.