Timer circuit including an analog ramp generator and a CMOS counter

摘要

A timer circuit provides a wide range of precise and substantially accurate time intervals. The timer circuit includes a ramp generator circuit having a first input for receiving an input signal to start a ramp signal, a second input for receiving a ramp timing control signal, and an output for providing a ramp signal. A comparator has a first input coupled to the output of the ramp generator, a second input coupled to a reference voltage source, and an output for providing an end ramp signal. A counter circuit has a first input for receiving the end ramp signal to begin counting, a second input for receiving a counter timing control signal, and an output for providing a terminal count signal. The end ramp signal and the terminal count signal are combined in an AND gate to provide a signal that is delayed by a predetermined amount from the input signal.