By Texas Instruments 112
Texas Instruments' TPS92070 is an advanced PWM controller ideal for use in low-power, offline, LED lighting applications. The integrated dimming interface circuit of the TPS92070 features a non-dissipative dimmer trigger control circuit. The TPS92070 controller provides DC LED current with no photometric ripple effects. The DC current also results in higher efficacy of the LEDs. The TPS92070 provides exponentially controlled light output based on the external dimmer position. High power factor is achieved with a valley fill circuit. Once a leading-edge dimmer is detected, the TPS92070 sets an output to disable the PFC circuit and thus optimizes driver operation. The LED current sense precision error amplifier implements deep dimming.