A Product Line of Diodes Incorporated AP2303 DDR BUS TERMINATION REGULATOR Description Pin Assignments The AP2303 is a low dropout linear regulator to generate termination voltage of DDR-SDRAM system. The regulator can source or sink up (Top View) to 1.75A current continuously. The output voltage is regulated to track tightly with the reference voltage (1/2V ) within 10mV. DDQ VIN NC 1 8 The AP2303 supports soft start-up when used to turn on the VCNTL and VREFEN. It integrates a shutdown circuit that will be triggered GND 2 7 NC once the voltage of VIN, VCNTL or VREFEN falls below a certain value. VREFEN 3 6 VCNTL AP2303 features over temperature protection and current limit VOUT NC 4 5 protection for both source and sink. SOIC-8 AP2303 is available in packages of SOIC-8 and PSOP-8. (Top View) Features Support DDR-II (V =0.9V), DDR-III (V =0.75V), DDR-IIIL 8 TT TT VIN 1 NC (V =0.675V), DDR-IV (V =0.6V) Application TT TT GND 2 Source and Sink up to 1.75A Current 7 NC Exposed Output Voltage Accuracy Over Full Load: 2% (Max.) Pad 3 VREFEN 6 VCNTL Soft Start-up and Shutdown along with V , V and V IN CNTL REFEN Rising and Shutdown along with V , V and V Dropping IN CNTL REFEN 4 5 NC VOUT Flexible Output by 2 External Resistors Requires Minimum 10F Output Ceramic Capacitor for Application PSOP-8 Current Limit Protection for Both Source and Sink OTSD Protection Applications Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) DDR-II/DDR-III/DDR-IIIL/DDR-IV Memory System Desktop PC, Notebook Mother Board Graphic Card STB, LCD-TV, Web-TV Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See A Product Line of Diodes Incorporated AP2303 Pin Descriptions Pin Number Pin Name Function 1 VIN Unregulated input supply. A small 10F MLCC should be connected from this pin to GND. 2 GND Ground Reference voltage input and active low shutdown control pin. Pulling the pin to ground turns off 3 VREFEN device by BJT or FET. When it is released, a soft-start will take for about 0.1ms. Regulated voltage output. A minimum of 10F ceramic capacitor to ground is required to assure 4 VOUT stability. 5, 7, 8 NC No Connection 6 VCNTL VCNTL supplies the internal control circuitry and provides the drive voltage. Exposed Pad The exposed pad should be connected to ground copper for better heat dissipation performance. Functional Block Diagram VCNTL VIN 6 1 Power On Reset OTSD Thermal POR Shutdown Error Amplifier and Soft Start EN 4 3 Enable VOUT VREFEN VREF Current Limit 2 GND 2 of 15 AP2303 September 2014 Diodes Incorporated www.diodes.com Document number: DS36546 Rev. 3 - 2 NEW PRODUCT