LIGHT-EMITTING SEMICONDUCTOR DEVICE DRIVER AND METHOD

摘要

An electronic device includes circuitry for driving a light-emitting diode (LED) or other light-emitting semiconductor device. The circuitry includes a first switch (NM5) coupled with the light-emitting semiconductor device (LED) for switching a current (ILED) through the light-emitting semiconductor device (LED); a sensing means (RSENS) for sensing a magnitude of the current (ILED) and outputting a respective sensing signal (SEN); an error amplifier (AMP2) for receiving the sensing signal (SEN) and a target value (ISET) for the current (ILED) for providing a first control voltage (VG1) based on the deviation of the actually sensed current magnitude and the current target value (ISET); a lowpass filter coupled to the error amplifier (AMP2) for filtering the first control voltage (VG1) and providing a second control voltage (VG2); a voltage follower (NM3) coupled to the lowpass filter and the first switch for receiving the second control voltage (VG2) and providing a third control voltage (VG3) for controlling the first switch's (NM5) switching activity; and a second switch (PM1, NM4) for switching a supply current (IDS3) of the voltage follower (NM3) for switching the voltage follower (NM3) on and off.