MAX1747 19-1788 Rev 0 10/00 Triple Charge-Pump TFT LCD DC-DC Converter General Description Features The MAX1747 triple charge-pump DC-DC converter Adjustable Outputs provides the regulated voltages required by active Up to +5.5V Main High-Power Output matrix thin-film transistor (TFT) liquid-crystal displays (LCDs) in a low-profile TSSOP package. One high- Up to +35V Positive Charge-Pump Output power and two low-power charge pumps convert the Down to -35V Negative Charge-Pump Output +2.7V to +4.5V input supply voltage into three indepen- 200kHz to 2MHz Adjustable Switching Frequency dent output voltages. +2.7V to +4.5V Input Supply The primary high-power charge pump generates an output voltage (V ) between 4.5V and 5.5V that is OUT Internal Power MOSFETs regulated within 1%. The low-power BiCMOS control 0.1A Shutdown Current circuitry and the low on-resistance (R ) power ON MOSFETs maximize efficiency. The adjustable switch- Internal Soft-Start ing frequency (200kHz to 2MHz) provides fast transient Power-Ready Output response and allows the use of small low-profile ceram- Internal Supply Sequencing ic capacitors. Fast Transient Response The dual low-power charge pumps independently regu- late one positive output (V ) and one negative output POS Ultra-Thin Solution (No Inductors) (V ). These additional outputs use external diode NEG Thin TSSOP Package (1.1mm max) and capacitor multiplier stages (as many stages as required) to regulate output voltages up to +35V and -35V. Ordering Information The constant switching frequency and a proprietary regulation algorithm minimize output ripple and capaci- PART TEMP. RANGE PIN-PACKAGE tor sizes for all three charge pumps. The MAX1747 is MAX1747EUP -40C to +85C 20 TSSOP available in the ultra-thin TSSOP package (1.1mm max height). Typical Operating Circuit Applications TFT Active-Matrix LCDs SUPM CXP INPUT Passive-Matrix Displays IN CXN Personal Digital Assistants (PDAs) MAIN OUTPUT OUT SHDN SUPP TO C Pin Configuration RDY SUPN FB DRVN TOP VIEW TGND 1 20 OUT MAX1747 TGND 2 19 CXP RDY 3 18 SUPM NEGATIVE FB 4 17 CXN DRVP OUTPUT FBN MAX1747 INTG 5 16 PGND IN 6 15 SUPP GND 7 14 DRVP REF REF 8 13 SUPN POSITIVE FBP OUTPUT TGND INTG FBP 9 12 DRVN GND PGND FBN 10 11 SHDN TSSOP Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLETriple Charge-Pump TFT LCD DC-DC Converter ABSOLUTE MAXIMUM RATINGS IN, SUPM, OUT, TGND to GND................................-0.3V to +6V Continuous Current into: SHDN........................................................................-0.3V to +1V SUPM, CXN, CXP, OUT..............................................800mA PGND to GND.....................................................................0.3V SUPP, SUPN, DRVN, DRVP........................................200mA SUPM to IN .........................................................................0.3V SHDN...........................................................................+100A CXN to PGND.........................................-0.3V to (V + 0.3V) All Other Pins....................................................................10mA SUPM CXP to PGND ............................(V - 0.3V) to (V + 0.3V) Continuous Power Dissipation (T = +70C) SUPM OUT A DRVN to GND.........................................-0.3V to (V + 0.3V) 20-Pin TSSOP (derate 10.9mW/C above +70C) .......879mW SUPN DRVP to GND..........................................-0.3V to (V + 0.3V) Operating Temperature Range............................-40C to +85C SUPP RDY to GND ...........................................................-0.3V to +14V Junction Temperature......................................................+150C SUPP, SUPN to GND..............................................-0.3V to +14V Storage Temperature Range .............................-65C to +150C INTG, REF, FB, FBN, FBP to GND...............-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C IN Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = V = +3.0V, V = V = +5V, TGND = PGND = GND, I = 22A, C = 2 4.7F, C = 0.22F, C = IN SUPM SUPP SUPN SHDN OUT REF INTG 1500pF, V = +5V, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) OUT A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UN ITS Input Supply Range V 2.7 4.5 V IN Input Undervoltage Threshold V V falling, 40mV hysteresis (typ) 2.2 2.4 2.6 V UVLO IN V = V = 1.5V, V = -0.2V, V = 5V, FB FBP FBN OUT Input Quiescent Supply I + IN no load on DRVN and DRVP CXN 0.9 1.0 mA Current I SUPM and CXP open V = V = 1.5V, V = -0.2V, V = 5V, FB FBP FBN OUT Output Quiescent Supply I no load on DRVN and DRVP CXN and 2.5 4.0 mA Q(OUT) Current CXP open Shutdown Supply Current V = 0, V = 5V 0.1 20 A SHDN SUPM Operating Frequency f I = 22 A 0.65 1 1.2 MHz OSC SHDN MAIN CHARGE PUMP Output Voltage Range V 4.5 5.5 V OUT Maximum Output Current I C = 0.47 F 200 mA OUT (M AX) X FB Regulation Voltage V 1.237 1.248 1.263 V FB FB Input Bias Current I V = 1.25V -50 +50 nA FB FB Integrator Transconductance 530 S FB Power-Ready Trip Level Rising edge 1.09 1.125 1.16 V FB Fault Trip Level Falling edge 1.100 V 4.096 Main Soft-Start Period s / F OSC NEGATIVE LOW-POWER CHARGE PUMP SUPN Input Supply Range V 2.7 13 V SUPN SUPN Quiescent Current I V = -0.2V, no load on DRVN 0.6 0.8 mA SUPN FBN SUPN Shutdown Current V = 0, V = 13V 0.1 10 A SHDN SUPN FBN Regulation Voltage V -50 0 +50 mV FBN 2 MAX1747