LT1183 Linear Technology, LT1183 Datasheet
LT1183
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LT1183 Summary of contents
Page 1
... The LT1182 per- mits 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 ...
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... ABSOLUTE MAXIMUM V , BAT, Royer, Bulb .............................................. 30V IN CCFL V , LCD V ............................................... 60V SW SW Shutdown ................................................................. 6V I Input Current .............................................. 10mA CCFL DIO Input Current (Peak, < 100ms) .................... 100mA LT1182: FBP, FBN, LT1183: FB Pin Current......... 2mA U PACKAGE/ORDER INFORMATION TOP VIEW 1 16 CCFL V CCFL PGND SW BULB CCFL BAT ...
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... Q I CCFL Switch On-Time SW1 V Reference Voltage REF Reference Output Impedance LT1182/LT1183/LT1184/LT1184F = SHUTDOWN = CCFL V = Open, DIO = GND, CCFL V CCFL SW = Open, (LT1182) FBN = FBP = GND, (LT1183 GND, CONDITIONS LT1182/LT1183 30V IN LT1184/LT1184F 30V IN SHUTDOWN = 0V, CCFL V = LCD V = Open (Note SHUTDOWN = 0V, CCFL V ...
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... P according to the following formula: D LT1182CS/LT1183CS/LT1184CS/LT1184FCS SHUTDOWN = CCFL V = Open, DIO = GND, CCFL V CCFL SW = Open, (LT1182) FBN = FBP = GND, (LT1183 GND, CONDITIONS Measured on LT1183 Measured on LT1184/LT1184F LT1182: Measured at FBP Pin, FBN = 1V, LCD V LT1183: Measured at FB Pin, LCD 30V, LCD ...
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... W U TYPICAL PERFORMANCE CHARACTERISTICS LT1182/LT1183 Supply Current vs Temperature 30V –75 – 50 – 100 125 150 175 TEMPERATURE ( C) LT1182 G01 Shutdown Input Bias Current vs Temperature 30V – ...
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... LT1182/LT1183/LT1184/LT1184F W U TYPICAL PERFORMANCE CHARACTERISTICS I Summing Voltage CCFL vs Temperature 0.53 0.52 0.51 0.50 0.49 0. 30V 0. 0.46 0. 0.44 IN 0.43 0.42 0.41 0.40 0.39 0.38 –75 – 50 – 100 125 150 TEMPERATURE ( C) LT1182 • G10 CCFL V Source Current for C I Programming Current CCFL vs Temperature 5.10 5. 100 A CCFL 5. CCFL 4. CCFL 4.90 4.85 4.80 –75 – ...
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... LT1182 • G22 CCFL High-Side Sense Supply Current vs Temperature 150 140 130 120 110 100 –75 – 50 – 100 125 150 175 TEMPERATURE ( C) LT1182 • G25 LT1182/LT1183/LT1184/LT1184F LCD V Low Clamp Voltage C vs Temperature 1.00 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.10 0 100 125 –75 –50 – ...
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... Temperature 3.0 2.5 2.0 1.5 1.0 0.5 0 –75 – 50 – 100 125 150 175 TEMPERATURE ( C) LT1182 • G32 LT1183 REF Output Impedance vs Temperature –75 –50 – 100 125 150 175 TEMPERATURE ( C) LT1182 • G35 FBP Input Bias Current vs Temperature 1 ...
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... Current Limit SW vs Duty Cycle 1.5 1.2 0 125 C 0.6 MINIMUM 0 DUTY CYCLE (%) LT1182 • G40 LT1182/LT1183/LT1184/LT1184F LCD V Sat Voltage SW vs Switch Current 2.0 1.6 1 – 125 C 0.8 0 0.3 0.6 0.9 1.2 SWITCH CURRENT (A) Forced Beta CCFL V SW 110 ...
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... I summing voltage in the LT1182/ CCFL LT1183/LT1184/LT1184F also a sense terminal for the LCD dual input error amplifier in the LT1182/LT1183. Connect external feedback divider networks that terminate to ground and frequency compensation components that terminate to ground directly to this pin for best regulation and performance ...
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... The typical quiescent current into the pin. If the CCFL regulator is not used in a floating lamp configuration, tie the Royer and BAT pins together. This pin is only available on the LT1182/LT1183/ LT1184F. V (Pin 12): This pin is the supply pin for the LT1182/ IN LT1183/LT1184/LT1184F ...
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... REF (Pin 11): This pin brings out the 1.244V reference. Its SW functions include the programming of negative contrast voltages with an external resistor divider network (LT1183 only) and the programming of lamp current for the I pin. LTC does not recommend using the REF pin for both functions at once ...
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... V2 V1 1.24V –12mV 0.45V – LCD LCD FBP FBN I CCFL PGND V C LT1183: FBP AND FBN ARE TIED TOGETHER TO CREATE FB AT PIN 10. THE REFERENCE IS BROUGHT OUT TO PIN 11. LT1182/LT1183/LT1184/LT1184F UNDER- THERMAL 2.4V VOLTAGE SHUTDOWN REGULATOR LOCKOUT 200kHz OSC ...
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... LT1182/LT1183/LT1184/LT1184F W BLOCK DIAGRAM LT1184/LT1184F CCFL Regulator Top Level Block Diagram SHUTDOWN 6 SHUTDOWN + CCFL 100 A – V REF V1 1.24V 0.465V 11 2 REF I CCFL LT1184/LT1184F: REFERENCE IS BROUGHT OUT TO PIN 1. PINS ARE NO CONNECT APPLICATIONS INFORMATION Introduction Current generation portable computers and instruments use backlit Liquid Crystal Displays (LCDs) ...
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... The switches turn OFF when switch current reaches a predetermined level. The operation of the CCFL regulator in the LT1184/LT1184F is identical to that in the LT1182/ LT1183. The control of output lamp current is obtained by using the output of a unique programming block to set current trip level. The contrast voltage is controlled by the output of a dual-input-stage error amplifier, which sets current trip level ...
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... This minimizes driver dissipation and provides rapid turn- off of the switch. The CCFL power switch is guaranteed to provide a minimum of 1.25A in the LT1182/LT1183/ LT1184/LT1184F and the LCD power switch is guaranteed to provide a minimum of 0.625A in the LT1182/LT1183. The anti-sat circuitry provides a ratio of switch current to driver current of about 50:1. Simplified Lamp Current Programming ...
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... The internal 0.1 high-side sense resistor on the LT1182/ LT1183/LT1184F is rated for a maximum DC current of 1A. However, this resistor can be damaged by extremely high surge currents at start-up. The Royer converter typically uses a few microfarads of bypass capacitance at the center tap of the transformer ...
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... Open-lamp conditions force the Royer converter to operate open-loop. Component stress is again worst-case with maximum input voltage conditions. The LT1182/LT1183/LT1184/LT1184F open-lamp pro- tection clamps the maximum transformer secondary volt- age to safe levels and transfers the regulator loop from current mode operation into voltage mode operation. ...
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... LCD Contrast Circuits The LCD contrast switching regulator on the LT1182/ LT1183 operates in many standard switching configura- tions and is used as a classic DC/DC converter. The dual- input-stage error amplifier easily regulates either positive or negative contrast voltages. Topology choices for the converter include single inductor and transformer-based solutions ...
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... C3B 2 35V 1000pF 220k C1* 0.068 F R3 100k Q2* Q1 100 H 1N5818 16 CCFL BULB 14 BAT LT1183 13 ROYER REF LCD V SW R10, 10k (CONTRAST C3A 2.2 F 35V VARYING THE V(CONTRAST) R1 VOLTAGE FROM GIVES 750 VARIABLE NEGATIVE CONTRAST + FROM – ...
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... Q1 ZETEX ZTX849 OR ROHM 2SC5001 L1 = COILTRONICS CTX210605 L2 = COILTRONICS CTX100-4 *DO NOT SUBSTITUTE COMPONENTS COILTRONICS (407) 241-7876 CURRENT GIVES CCFL 0mA TO 6mA LAMP CURRENT FOR A TYPICAL DISPLAY. D5 BAT85 C7 SHUTDOWN LT1182/LT1183/LT1184/LT1184F 6mA LAMP C2 27pF 3kV C3B 2 ...
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... TA04 TO I PIN CCFL LT1184/LT1184F I 1182 TA05 V (PWM 1kHz PWM PIN CCFL 1182 TA06 LT1183 PIN CCFL 1182 TA07 V (PWM 1kHz PWM 10 to 100 PIN CCFL LT1184/LT1184F I 1182 TA12 ...
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... Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LT1182/LT1183/LT1184/LT1184F N LT1182 LCD Contrast Positive Boost Converter ...
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... LT1182/LT1183/LT1184/LT1184F U TYPICAL APPLICATIONS LT1182 LCD Contrast Positive to Negative/Charge Pump Converter 1 CCFL CCFL V PGND 2 I CCFL 3 DIO LT1182 4 CCFL AGND 6 C8 SHDN R7 0.068 F 33K 7 LCD LCD LCD V PGND RELATED PARTS PART NUMBER FREQUENCY SWITCH CURRENT LT1107 63kHz 1A Hysteretic LT1172 100kHz 1 ...