LD6902

High Voltage Linear Regulator LD6902 12/15/2005 REV: 03 General Description The LD6902 is a high voltage, micropower linear regulator, which features wide input voltage, low-noise, low-dropout and low-quiescent current. The precision of feedback reference voltage is within ±2% and output current is up to 90mA. The LD6902 can also be used as a WLED driver. The external soft start function provides a flexible way to limit the startup current. Features z ±2% feedback reference z Shutdown current <1µA (TYP) z High input voltage: up to 21V z Thermal shutdown and current limit protection z Soft start operation Applications z Microcontroller Power z Hand-Held Instruments +Patent pending Typical Application VIN/15V 0.1µF/X5R 3.3nF VIN OUT LD6902 CE R1/100K SS GND FB R2/20K VOUT/7.5V 4.7µF/X5R Fig.1 High voltage linear regulator application Leadtrend Technology Corporation LD6902-DS-03 December, 2005 1 LD6902 VIN 15V 0.1µF/X5 15nF VIN OUT LD6902 CE SS GND FB R1 20mA 4.7µF/X5R R2 R3 2 WLED 3 WLED R1 62K 62K R2 3.24K 2K R3 47.5Ω 47.5Ω Fig.2 WLED driver application VIN 0.1µF/X5 200Hz to 1KHz 15nF Css Q1 VIN OUT LD6902 CE R1 SS FB GND R2 R3 To avoid inrush current during the first start up cycle, please turn on Q1 at the first CE pin pulse and then turn off Q1. Fig.3 WLED driver application COUT Leadtrend Technology Corporation LD6902-DS-03 December, 2005 2 Pin Configuration SOT-26 (TOP VIEW) CE SS FB 65 Y WP 02 12 4 3 Y : Year code (D: 2004, ...