Abstract: A light source module is provided. The light source module includes a full wave rectifier, a constant current output integrated circuit (IC) and at least one high operating voltage light emitting diode (HVLED) die coupled between the constant current output IC and a ground. The full wave rectifier generates a rectified signal according to an alternating current (AC) power. The constant current output IC outputs a constant current signal according to the rectified signal. A brightness of the HVLED die is determined by the constant current signal.

Abstract: A light emitting diode (LED) lamp. Brightness of the LED lamp is controlled by a dimmer and an external alternating current (AC) source is received via the dimmer. The LED lamp includes at least one LED, a rectifying-modulating-driving apparatus and a current holding compensator. The rectifying-modulating-driving apparatus is coupled between the LED and the dimmer for bridge-rectifying and modulating an AC source with a conducting angle from the dimmer to drive the LED. The current holding compensator is coupled to the rectifying-modulating-driving apparatus to provide a compensation current when the AC source with the conducting angle is lower than a voltage after being bridge-rectified.