 GENERAL DESCRIPTION

AX3531 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version. Supply current with no load is 200uA and drops to <1uA in shutdown. The 2.8V to 5.5V input voltage range makes AX3531 ideally suited for single Li-Ion, two to three AA battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Switching frequency is internally set at 1.25MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and decreases need of an external schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. AX3531 is available in small TSOT-23-6L package.

 FEATURES

- 2.8V to 5.5V Input Voltage Range

- Output Voltage from 0.6V to VIN

- High Efficiency: Up to 96%

- 1.25MHz Constant Frequency Operation

- Up to 2A Output Current

- Quiescent Current: 200uA (Typical)

- No Schottky Diode Required

- Current Mode Operation for Excellent Line and Load Transient Response

- Current limit, Enable function

- Short Circuit Protect (SCP)

- Build in soft start function

- ≤ 1μA Shutdown Current

- TSOT-23-6L Pb-Free package

- RoHS and Halogen free compliance.