LT1183 Datasheet | Linear Technology

LT1182/LT1183/LT1184/LT1184F CCFL/LCD Contrast Switching Regulators Features s s s s s s s DESCRIPTION The LT®1182/LT1183 are dual current mode switching regulators that provide the control function for Cold Cathode Fluorescent Lighting (CCFL) and Liquid Crystal Display (LCD) Contrast. The LT1184/LT1184F provide only the CCFL function. The ICs include high current, high efficiency switches, an oscillator, a reference, output drive logic, control blocks and protection circuitry. The LT1182 permits positive or negative voltage LCD contrast operation. The LT1183 permits unipolar contrast operation and pins out an internal reference. The LT1182/LT1183 support grounded and floating lamp configurations. The LT1184F supports grounded and floating lamp configurations. The LT1184 supports only grounded lamp configurations. The , LTC and LT are registered trademarks of Linear Technology Corporation. Wide Input Voltage Range: 3V to 30V Low Quiescent Current High Switching Frequency: 200k Hz CCFL Switch : 1.25A, LCD Switch: 625m A Grounded or Floating Lamp Configurations Open-Lamp Protection Positive or Negative Contrast Capability U APPLICATIONS s s s s Notebook and Palmtop puters Portable Instruments Automotive Displays Retail Terminals TYPICAL APPLICATION 90% Efficient Floating CCFL Configuration with Dual Polarity LCD Contrast UP TO 6m A ALUMINUM ELECTROLYTIC IS REMENDED FOR C3B WITH AN ESR ≥ 0.5Ω TO PREVENT DAMAGE TO THE LT1182 HIGH-SIDE SENSE RESISTOR DUE TO SURGE CURRENTS AT TURN-ON. C1 MUST BE A LOW LOSS CAPACITOR, C1 = WIMA MKP-20 Q1, Q2 = ZETEX ZTX849 OR ROHM 2SC5001 L1 = COILTRONICS CTX210605 L2 = COILTRONICS CTX100-4 L3 = COILTRONICS CTX02-12403 - DO NOT SUBSTITUTE PONENTS COILTRONICS (407) 241-7876 0µA TO 45µA ICCFL CURRENT GIVES 0m A TO 6m A BULB CURRENT. THIS IS EQUAL TO 0% TO 90% DUTY CYCLE FOR THE PWM SIGNAL. R4 46.4k 1% C6 2.2µF C5 1000p F R2 220k 3 2 1 C3B 2.2µF 35V R1 750Ω 4 5 LAMP 10 6 C2 27p F 3k V L1 CCFL BACKLIGHT APPLICATION CIRCUITS CONTAINED...