AT1691 Global Mixed-mode Technology 1.5MHz, 1A High Efficiency Buck Converter General Description Features The AT1691 provides complete control for a DC/DC converter optimized for high-performance microprocessor applications. It is operated on current mode architecture for excellent line and load transient response. 1.5MHz operation frequency is allowing the use of small surface mount inductor and capacitor. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. The AT1691 is a family of low-noise synchronous step-down DC/DC converters that is ideally suited for systems powered from a 1-cell Li-ion battery or from a 3-cell to 4-cell NiCd, NiMH, or alkaline battery. It can also be used to USB-Based power system. Input voltage: 2.5V ~5.5V High efficiency (95%) No Schottky Diode Required 1A Output Current at 5V Input 3.3V Output 1.5MHz Switching Frequency Built-in ON/OFF Function Low Dropout Operation: 100% Duty Cycle Thermal Protection Tiny 6-Lead TDFN2X2 Package RoHS Compliant Applications Mobile Phones Wireless and DSL modems Power Supply for Portable Devices Ordering Information ORDER NUMBER MARKING OUTPUT VOLTAGE (V) TEMP. RANGE PACKAGE (Green) AT1691RB1U A161 Adjustable -40°C~ +85°C TDFN2X2-6 Note: RB: TDFN2X2-6 1: Bonding Code U: Tape & Reel Pin Configuration Typical Application Circuit NC 1 EN 2 VIN 3 Thermal Pad 3 VIN 5V AT1691 6 FB 5 GND 4 LX LX VIN AT1691 CIN 4.7µF 2 EN FB 4 2.2µH (optional) CFB VOUT 3.3V/1A R1 COUT 10µF 6 GND 5 TDFN2X2-6 VOUT = 0.6V × (1+ R2* R1 ) R2 *R2= 150K for stability consideration. Note: Recommend connecting the Thermal Pad to the Ground for excellent power dissipation. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.2 Jun 21, 2012 1