Patent ID: 6791397
Filing Date: 2004-09-14
Classification: G05F

Abstract:
A constant current circuit delivering a constant current to a load connected between first and second output terminals, comprising:a reference current generator configured to generate a reference current; a current mirror circuit configured to amplify the reference current; an output transistor configured to deliver the constant current based on an output of the current mirror circuit; a signal source configured to deliver a pulse control signal having a pulse-shaped waveform; an auxiliary switching circuit having a switch terminal configured to deliver a switch signal in response to the pulse control signal, and a discharge terminal configured to deliver a discharge signal to the current mirror circuit when the switch signal is stopped, including: a delay circuit configured to receive the pulse control signal so as to deliver the switch signal, a first control signal delayed from the switch signal, and a second control signal delayed from the first control signal; and an output circuit configured to deliver the discharge signal to the discharge terminal, a switch circuit configured to turn off the output transistor with receiving the switch signal.