This reference design delivers a high efficiency LED driver circuit with dimming function using the boost converter TPS61021A. The PWM dimming method can be used in one or two cell AA battery input applications: and the analog dimming method can be used in one cell AA battery input applications. PMP15037 can realize the dimming function through the addition of several resistors and one MOSFET into the circuit: making it an cost-effective and high efficiency solution for LED driver applications.