R2A20101BM

www.DataSheet4U.com R2A20101BM/NP Monolithic Synchronous Step-Down DC/DC Converter REJ03D0790-0300 Rev.3.00 May 14, 2008 Features Built-in low Ron power MOS FETs Pch Ron = 0.30 Ω (Typ), Nch Ron = 0.14 Ω (Typ) High switching frequency: 2 MHz (Max) Output current: 650 mA (Max) Output ON/OFF control Vout control Power good monitor Current share for redundant power supply operation Vout = 0.5 V to (VIN – 0.5) V Application POL (Point of Load) power supplies Power supply for microcomputer systems MCU-Core, I/O, Memory (DDR, SRAM, FLASH, HDD, etc.), FPGA, DSP, Graphic Processor Battery powered equipment systems Cellular phone (CDMA power amplifier, MCU, DSP, ASIC), PDA, Digital camera, Portable game, Handy terminal Operating Circuit Example Vin 2.5V to 5.5V Cin 4.7 µ F Power Good Signal Output Error Amp. Output (for Current Share) Vref Input (for Vout Control) R2A20101 VIN ON/ OFF PWGD EAO LX PGND CRFB VFB L1 2.2 µ H Iout: Up to 650mA Vout 1.8V Rcf2 68k Ω Ccf1 47pF Rvf2 390k Ω Rvf1 150k Ω Rcf1 100k Ω Cout 4.7 µ F AGND VREF (Internal Vref = 0.5V) Notes: 1. All ceramic capacitor 2. Rcf1 : Rcf2(recommend) = 3 : 2 3. fsw is adjustable by Ccf1, Rcf1, and Rcf2. REJ03D0790-0300 Rev.3.00 May 14, 2008 Page 1 of 9 R2A20101BM/NP Block Diagram ON/OFF www.DataSheet4U.com SHDN Shut Down PWGD Power Good Comparator UVLO VIN Ref 1.15V 1.3MΩ VREF – + Vref × 10% + – PWM Control Logic LX PGND CRFB VFB AGND SS EAO 1MΩ 1.5kΩ Error Amplifier Absolute Ma...