MAX17114 19-4820 Rev 0 7/09 Multi-Output Power Supply with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVs General Description Features The MAX17114 generates all the supply rails for thin-film S 8.0V to 16.5V IN Supply-Voltage Range transistor liquid-crystal display (TFT LCD) TV panels S Selectable Frequency (500kHz/750kHz) operating from a regulated 12V input. It includes a step- S Current-Mode Step-Up Regulator down and a step-up regulator, a positive and a negative Fast Load-Transient Response charge pump, an operational amplifier, a high-accuracy, High-Accuracy Output Voltage (1.0%) high-voltage gamma reference, and a high-voltage Built-In 20V, 3.5A, 100mI MOSFET switch control block. The MAX17114 can operate from High Efficiency input voltages from 8V to 16.5V and is optimized for an Adjustable Soft-Start LCD TV panel running directly from 12V supplies. Adjustable Current Limit The step-up and step-down switching regulators feature Low Duty-Cycle Operation (13.2V - 13.5V AVDD) IN internal power MOSFETs and high-frequency opera- S Current-Mode Step-Down Regulator tion allowing the use of small inductors and capacitors, Fast Load-Transient Response resulting in a compact solution. The step-up regulator Built-In 20V, 3.2A, 120mI MOSFET provides TFT source driver supply voltage, while the High Efficiency step-down regulator provides the system with logic sup- 3ms Internal Soft-Start ply voltage. Both regulators use fixed-frequency current- S Adjustable Positive Charge-Pump Regulator mode control architectures, providing fast load-transient response and easy compensation. A current-limit func- S Adjustable Negative Charge-Pump Regulator tion for internal switches and output-fault shutdown pro- S Integrated High-Voltage Switch with Adjustable tects the step-up and step-down power supplies against Turn-On Delay fault conditions. The MAX17114 provides soft-start func- S High-Speed Operational Amplifier tions to limit inrush current during startup. In addition, 200mA Short-Circuit Current the MAX17114 integrates a control block that can drive 45V/s Slew Rate an external p-channel MOSFET to sequence power to source drivers. S High-Accuracy Reference for Gamma Buffer 0.5% Feedback Voltage The positive and negative charge-pump regulators pro- Up to 30mA Load Current vide TFT gate-driver supply voltages. Both output volt- Low-Dropout Voltage 0.5V at 60mA ages can be adjusted with external resistive voltage- dividers. A logic-controlled, high-voltage switch block S External p-Channel Gate Control for AVDD allows the manipulation of the positive gate-driver supply. Sequencing The MAX17114 includes one high-current operational S XAO Comparator amplifier designed to drive the LCD backplane (VCOM). S Input Undervoltage-Lockout and Thermal- The amplifier features high output current (Q200mA), fast Overload Protection slew rate (45V/Fs), wide bandwidth (20MHz), and rail-to- S 48-Pin, 7mm x 7mm, Thin QFN Package rail outputs. Also featured in the MAX17114 is a high-accuracy, high- Ordering Information voltage adjustable reference for gamma correction. PART TEMP RANGE PIN-PACKAGE The MAX17114 is available in a small (7mm x 7mm), MAX17114ETM+ -40NC to +85NC 48 TQFN-EP* ultra-thin (0.8mm), 48-pin, TQFN-EP package and oper- ates over the -40NC to +85NC temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. Applications Pin Configuration and Simplified Operating Circuit appear LCD TV Panels at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEMulti-Output Power Supply with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVs ABSOLUTE MAXIMUM RATINGS INVL, IN2, VOP, EN, FSEL to GND .......................-0.3V to +24V VREF I to GND ......................................................-0.3V to +24V PGND, OGND, CPGND to GND ..........................-0.3V to +0.3V VREF O to GND ...................................-0.3V to (VREF I + 0.3V) DLY1, GVOFF, THR, VL to GND ..........................-0.3V to +7.5V REF Short Circuit to GND ..........................................Continuous VREF 0, VREF I, FBP, FBN, FB1, FB2, COMP, SS, CLIM, RMS LX1 Current (total for both pins) ..................................3.2A RMS PGND Current (total for both pins) ..............................3.2A XAO, VDET, VREF FB, OUT to GND .........-0.3V to (VL + 0.3) GD, GD I to GND ..................................................-0.3V to +24V RMS IN2 Current (total for both pins) ..................................3.2A RMS LX2 Current (total for both pins) ..................................3.2A LX1 to PGND .........................................................-0.3V to +24V OPP, OPN, OPO to OGND ....................... -0.3V to (VOP + 0.3V) RMS DRVN, DRVP Current ..................................................0.8A RMS VL Current ..................................................................50mA DRVP to CPGND .................................... -0.3V to (SUPP + 0.3V) DRVN to CPGND ....................................-0.3V to (SUPN + 0.3V) Continuous Power Dissipation (T +70NC) A = LX2 to PGND ................................................-0.7 to (IN2 + 0.3V) 48-Pin TQFN (derate 38.5mW/NC above +70NC) ....3076.9mW SUPN to GND .............................................-0.3V to (IN2 + 0.3V) Operating Temperature Range .......................... -40NC to +85NC SUPP to GND .......................................... -0.3V to (GD I + 0.3V) Junction Temperature .....................................................+160NC BST to VL ...............................................................-0.3V to +30V Storage Temperature Range ............................ -65NC to +165NC VGH to GND ..........................................................-0.3V to +40V Lead Temperature (soldering, 10s) .................................. +300N VGHM, DRN to GND ................................-0.3V to (VGH + 0.3V) VGHM to DRN .......................................................-0.3V to +40V 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 (Circuit of Figure 1, V = V = V = 12V, V = V = 15V, T = 0C to +85C. Typical values are at T = +25NC, INVL IN2 IN OPO AVDD A A unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS GENERAL INVL, IN2 Input-Voltage Range 8 16.5 V Only LX2 switching (VFB1 = VFBP = 1.5V, VFBN = 0V), INVL + IN2 Quiescent Current 10 20 mA EN = VL, VFSEL = 1V LX2 not switching (VFB1 = VFB2 = VFBP = 1.5V, INVL + IN2 Standby Current 2 5 mA VFBN = 0V), EN = VL, VFSEL = high FSEL = INVL or high impedance 630 750 870 SMPS Operating Frequency kHz FSEL = GND 420 500 580 INVL Undervoltage-Lockout INVL rising, 200mV typical hysteresis 6.0 7.0 8.0 V Threshold VL REGULATOR IVL = 25mA, VFB1 = VFB2 = VFBP = 1.1V, VFBN = 0.4V VL Output Voltage 4.859 5 5.15 V (all regulators switching) VL Undervoltage-Lockout VL rising, 50mV typical hysteresis 3.5 3.9 4.3 V Threshold REFERENCE REF Output Voltage No external load 1.2375 1.250 1.2625 V REF Load Regulation 0A < ILOAD < 50FA 10 mV REF Sink Current In regulation 10 FA REF Undervoltage-Lockout Rising edge, 250mV typical hysteresis 1.0 1.2 V Threshold 2 MAX17114