UM3500 Datasheet | Union Semiconductor

Description The UM3500 is a 1.5MHz constant frequency, slope pensated current mode PWM step-down converter. The device integrates a main switch and a synchronous rectifier for high efficiency without an external Schottky diode. It is ideal for powering portable equipment that runs from a single cell lithium-Ion (Li+) battery. The UM3500 can supply 600m A of load current from a 2.5V to 5.5V input voltage. The output voltage can be regulated as low as 0.6V. The UM3500 can also run at 100% duty cycle for low dropout operation, extending battery life in portable system. Pulse Skipping Mode operation at light loads provides very low output ripple voltage for noise sensitive applications. The UM3500 is available in a low profile SOT23-5 package. Applications z Cellular and Smart Phones z Microprocessors and DSP Core Supplies z Wireless and DSL Modems z PDAs, GPS z MP3 Player z Portable Instruments Features z High Efficiency: Up to 96% z 1.5MHz Constant Switching Frequency z 600m A Output Current z Integrated Main Switch and Synchronous Rectifier. No External Schottky Diode. z 2.5V to 5.5V Input Voltage Range z Output Voltage as Low as 0.6V z 100% Duty Cycle in Dropout z Low Quiescent Current: 50µA z Short Circuit Protection z Thermal Fault Protection z <1µA Shutdown Current z Lead Free SOT23-5 Package Pin Configurations Top View WW: Week Code UM3500 SOT23-5 ________________________________________________________________________ http://.union-ic. Rev.04 May.2016 1/11 Ordering Information Part Number UM3500 Packaging Type SOT23-5 Marking Code LTA5 Shipping Qty 3000pcs/7Inch Tape & Reel Pin Description Pin Number 2 3 4 5 Symbol Function RUN GND SW VIN VFB Regulator enables control input. Drive RUN above 1.0V to turn on the part. Drive RUN below 0.4V to turn it off. In shutdown, all functions are disabled drawing <1μA supply current. Do not leave RUN floating. Ground. Power switch output. It is the switch node connection to Inductor. This pin...