LT1182/LT1183/LT1184/LT1184F CCFL/LCD Contrast Switching Regulators FEATURES DESCRIPTION n Wide Input Voltage Range: 3V to 30V The LT 1182/LT1183 are dual current mode switching n Low Quiescent Current regulators that provide the control function for Cold Cath- n High Switching Frequency: 200kHz ode Fluorescent Lighting (CCFL) and Liquid Crystal Display n CCFL Switch: 1.25A, LCD Switch: 625mA (LCD) Contrast. The LT1184/LT1184F provide only the n Grounded or Floating Lamp Configurations CCFL function. The ICs include high current, high efficiency n Open-Lamp Protection switches, an oscillator, a reference, output drive logic, n Positive or Negative Contrast Capability control blocks and protection circuitry. The LT1182 per- mits positive or negative voltage LCD contrast operation. U APPLICATIONS The LT1183 permits unipolar contrast operation and pins out an internal reference. The LT1182/LT1183 support n Notebook and Palmtop Computers grounded and floating lamp configurations. The LT1184F n Portable Instruments supports grounded and floating lamp configurations. The n Automotive Displays LT1184 supports only grounded lamp configurations. The n Retail Terminals , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION 90% Efficient Floating CCFL Configuration with Dual Polarity LCD Contrast UP TO 6mA ALUMINUM ELECTROLYTIC IS RECOMMENDED FOR C3B WITH AN CCFL BACKLIGHT APPLICATION CIRCUITS CONTAINED IN THIS LAMP C2 ESR 0.5 TO PREVENT DAMAGE TO THE LT1182 HIGH-SIDE DATA SHEET ARE COVERED BY U.S. PATENT NUMBER 5408162 27pF SENSE RESISTOR DUE TO SURGE CURRENTS AT TURN-ON. AND OTHER PATENTS PENDING 3kV 10 6 C1 MUST BE A LOW LOSS CAPACITOR, C1 = WIMA MKP-20 L1 Q1, Q2 = ZETEX ZTX849 OR ROHM 2SC5001 L1 = COILTRONICS CTX210605 3 2 1 4 5 BAT L2 = COILTRONICS CTX100-4 + 8V TO 28V C3B + C3A 2.2F L3 = COILTRONICS CTX02-12403 C5 2.2F EITHER NEGCON OR POSCON R2 35V 1000pF 35V MUST BE GROUNDED. 220k *DO NOT SUBSTITUTE COMPONENTS GROUNDING NEGCON GIVES R1 COILTRONICS (407) 241-7876 VARIABLE POSITIVE CONTRAST C1* 750 FROM 10V TO 30V. 0.068F 0A TO 45A ICCFL + C12 GROUNDING POSCON GIVES CURRENT GIVES 2.2F VARIABLE NEGATIVE CONTRAST 0mA TO 6mA R3 35V FROM 10V TO 30V. 100k BULB CURRENT. Q2* Q1* THIS IS EQUAL TO POSCON D5 0% TO 90% DUTY D3 L3 BAT85 CYCLE FOR THE 1N5934A 6 C11 + PWM SIGNAL. L2 4 D1 24V 22F 100H 1N5818 35V R4 D2 1 16 2 9 CCFL 46.4k CCFL V 1N914 SW PGND R5, 43.2k, 1% V (PWM) 1% NEGCON 2 15 0V TO 5V I BULB N = 1:2 CCFL D4 1kHz PWM + 1N914 C6 3 14 DIO BAT 2.2F C7, 1F R12 LT1182 4 13 V IN 20k CCFL V ROYER C 3V + C4 5 12 R13 AGND V 2.2F IN 8.45k 1% 6 11 SHUTDOWN SHDN FBP C8, 0.68F C9, 0.01F R14 7 10 C10 1.21k LCD V FBN C 0.01F 1% R7, 10K 8 9 LCD LCD V SW PGND R9, 4.99k, 1% R10, 10k, 1% R11, 20k, 1% 5V 1182/3 TA01 1 U ULT1182/LT1183/LT1184/LT1184F DESCRIPTION LT1184/LT1184F pin out the reference for simplified pro- current. An active low shutdown pin typically reduces total gramming of lamp current. supply current to 35A for standby operation. A 200kHz switching frequency minimizes the size of required mag- The LT1182/LT1183/LT1184/LT1184F operate with input netic components. The use of current mode switching supply voltages from 3V to 30V. The ICs also have a techniques with cycle-by-cycle limiting gives high reliabil- battery supply voltage pin that operates from 4.5V to 30V. ity and simple loop frequency compensation. The LT1182/ The LT1182/LT1183 draw 9mA typical quiescent current LT1183/LT1184/LT1184F are all available in 16-pin nar- while the LT1184/LT1184F draw 6mA typical quiescent row SO packages. ABSOLUTE MAXIMUM RATINGS LT1183/LT1184/1184F: REF Pin Source Current .... 1mA V , BAT, Royer, Bulb .............................................. 30V IN Junction Temperature (Note 1)............................ 100C CCFL V , LCD V ............................................... 60V SW SW Operating Ambient Temperature Range ..... 0C to 100C Shutdown ................................................................. 6V Storage Temperature Range ................. 65C to 150C I Input Current .............................................. 10mA CCFL Lead Temperature (Soldering, 10 sec).................. 300C DIO Input Current (Peak, < 100ms) .................... 100mA LT1182: FBP, FBN, LT1183: FB Pin Current......... 2mA PACKAGE/ORDER INFORMATION TOP VIEW TOP VIEW ORDER PART ORDER PART CCFL V CCFL V CCFL PGND 1 16 CCFL PGND 1 16 SW SW NUMBER NUMBER BULB BULB I 2 15 I 2 15 CCFL CCFL BAT BAT DIO 3 14 DIO 3 14 LT1182CS LT1183CS ROYER ROYER CCFL V 4 13 CCFL V 4 13 C C V V AGND 5 12 AGND 5 12 IN IN FBP REF SHUTDOWN 6 11 SHUTDOWN 6 11 FBN FB LCD V 7 10 LCD V 7 10 C C LCD V LCD V LCD PGND 8 9 LCD PGND 8 9 SW SW S PACKAGE S PACKAGE 16-LEAD PLASTIC SO 16-LEAD PLASTIC SO T = 100C, = 100C/W T = 100C, = 100C/W JMAX JA JMAX JA TOP VIEW TOP VIEW ORDER PART ORDER PART CCFL PGND 1 16 CCFL V CCFL PGND CCFL V NUMBER SW NUMBER 1 16 SW I 2 15 BULB I BULB 2 15 CCFL CCFL DIO 3 14 BAT DIO BAT 3 14 LT1184FCS LT1184CS CCFL V 4 13 NC CCFL V ROYER 4 13 C C AGND 5 12 V AGND V IN 5 12 IN SHUTDOWN 6 11 REF SHUTDOWN REF 6 11 NC 7 10 NC NC NC 7 10 NC 8 9 NC NC NC 8 9 S PACKAGE S PACKAGE 16-LEAD PLASTIC SO 16-LEAD PLASTIC SO T = 100C, = 100C/W T = 100C, = 100C/W JMAX JA JMAX JA Consult factory for Industrial and Military grade parts 2 U W U U WWW U