
Champion Microelectronic
GENERAL DESCRIPTION
The CM3706A 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 300uA and drops to <1uA in shutdown. The 2.5V to 6.5V input voltage range makes the CM3706A ideally suited for single Li-Ion, two to four AA battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. PWM pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage.
FEATURES
◆ High Efficiency: Up to 96%
◆ 1.5Mhz Constant Switching Frequency
◆ 600mA Output Current at VIN=3V
◆ Integrated Main switch and synchronous rectifier. No Schottky Diode Required
◆ 2.5V to 6.5V Input Voltage Range
◆ Output Voltage as Low as 0.6V
◆ 100% Duty Cycle in Dropout
◆ Low Quiescent Current: 300µA
◆ Slope Compensated Current Mode Control for Excellent Line and Load Transient Response
◆ Short Circuit Protection
◆ Thermal Fault Protection
◆ <1uA Shutdown Current
◆ Space Saving 5-Pin Thin TSOT23 package
APPLICATIONS
◆ Cellular and Smart Phones
◆ Microprocessors and DSP Core Supplies
◆ Wireless and DSL Modems
◆ PDAs
◆ MP3 / MP4 Player
◆ Portable Instruments
◆ Digital Still and Video Cameras