AX3531

AX3531 1.25MHz, 2A Synchronous Step-Down Converter  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 1/10 Axelite Confidential Materials, do not copy or distribute without written consent. Rev.1.0 Jul.22, 2011 AX3531  BLOCK DIAGRAM VIN OSC REF 0.6V SET SLOPE COMP Isense AMP So...