LTC3450 Triple Output Power Supply for Small TFT-LCD Displays U FEATURES DESCRIPTIO ■ The LTC®3450 is a complete power converter solution for small thin film transistor (TFT) liquid crystal display (LCD) panels. The device operates from a single Lithium-Ion cell, 2- to 3-cell alkaline input or any voltage source between 1.5V and 4.6V. ■ ■ ■ ■ ■ ■ ■ ■ ■ Generates Three Voltages: 5.1V at 10mA – 5V, –10V, or –15V at 500µA 10V or 15V at 500µA Better than 90% Efficiency Low Output Ripple: Less than 5mVP-P Complete 1mm Component Profile Solution Controlled Power-Up Sequence: AVDD/VGL/VGH All Outputs Disconnected and Actively Discharged in Shutdown Low Noise Fixed Frequency Operation Frequency Reduction Input for High Efficiency in Blank Mode Ultralow Quiescent Current: 75µA (Typ) in Scan Mode Available in a 3mm × 3mm 16-Pin QFN Package U APPLICATIO S ■ ■ ■ The synchronous boost converter generates a low noise, high efficiency 5.1V, 10mA supply. Internal charge pumps are used to generate 10V, 15V, and –5V, –10V or –15V. Output sequencing is controlled internally to insure proper initialization of the LCD panel. A master shutdown input reduces quiescent current to <2µA and quickly discharges each output for rapid turn off of the LCD panel. The LTC3450 is offered in a low profile (0.75mm), 3mm × 3mm 16-pin QFN package, minimizing the solution profile and footprint. , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Cellular Handsets with Color Display Handheld Instruments PDA U TYPICAL APPLICATIO 5.1V, –10V, 15V Triple Output TFT-LCD Supply 47µH 8 2.2µF 6 BLANK SCAN 4 7 SW VOUT 11 C1 + 10 – C1 VIN MODE V2X LTC3450 OFF ON 5 C2 + C2 – SHDN V3X 9 GND VINV VNEG C3 – C3 + 3 2 2.2µF 95 0.1µF 100µH 0.47µF 14 15 100 5mA LOAD 12 13 AVDD Efficiency vs VIN AVDD 5.1V/10mA 0.1µF VGH (3 × AVDD) 15V/500µA EFFICIENCY (%) VIN 1.5V TO 4.6V 90 47µH 85 80 16 0.1µF 75 0.1µF 70 1.5 1 0.1µF VGL –10V/500µA 2.0 2.5 3.0 3.5 VIN (V) 4.0 4.5 5.0 3450 TA01b 3450 TA01 3450fa 1 LTC3450 U W W W ABSOLUTE AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO (Note 1) (Referred to GND) ORDER PART NUMBER C2– C2+ VINV V3X TOP VIEW VIN, SW.......................................................... – 0.3 to 7V SHDN, MODE ................................................. – 0.3 to 7V VOUT .......................................................................... – 0.3 to 5.5V VNEG ........................................................................ –17V to 0.3V Operating Temperature Range LTC3450E (Note 4) ............................. – 40°C to 85°C Storage Temperature Range ................. – 65°C to 125°C 16 15 14 13 C3+ 1 C3 – LTC3450EUD 12 V2X 2 11 C1 17 VNEG 3 + 10 C1– MODE 4 6 7 8 SHDN VIN VOUT SW 9 5 GND UD PART MARKING LAAC UD PACKAGE 16-LEAD (3mm × 3mm) PLASTIC QFN EXPOSED PAD IS VNEG (PIN 17) MUST BE SOLDERED TO PCB TJMAX = 125°C, θJA = 68°C/W Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, VOUT = 5.2V unless otherwise noted. PARAMETER CONDITIONS MIN ● Input Voltage Range TYP 1.5 VIN Quiescent Supply Current MODE = VIN 75 VOUT Quiescent Supply Current MODE = VIN 80 VIN Quiescent Supply Current MODE = GND 30 VOUT Quiescent Supply Current MODE = GND 13 VIN Quiescent Current SHDN = GND, VOUT OPEN MAX UNITS 4.6 V 130 µA 50 µA µA µA 0.01 2 µA 5.100 5.151 V 5V Boost Regulator VOUT Output Voltage Load on VOUT = 5mA 5.049 VOUT Efficiency Load on VOUT = 5mA, (Note 2) 90 % VOUT Maximum Output Current L = 47µH, (Note 2) 11 mA 120 mA Switch Current Limit 90 Switching Frequency—Boost MODE = VIN 550 kHz Switching Frequency—Boost MODE = GND 15.62 kHz Charge Pumps V2X Output Voltage Load on V2X = 100µA ● 9.792 10.1 10.608 V 3450fa 2 LTC3450 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, VOUT = 5.2V unless otherwise noted. PARAMETER CONDITIONS V3X Output Voltage Load on V3X = 100µA V2X Efficiency Load on V2X = 100µA, (Note 2) 90 V3X Efficiency Load on V3X = 100µA, (Note 2) 80 % Output Impedance V2X, V3X Flying Capacitors = 0.1µF 1 kΩ VNEG Output Voltage Load on VNEG = 100µA, VINV = V2X VNEG Efficiency Load on VNEG = 100µA (Note 2) 80 % Output Impedance VNEG Flying Capacitor = 0.1µF 1 kΩ Switching Frequency Charge Pumps MODE = VIN 62.5 kHz Switching Frequency Charge Pumps MODE = GND VNEG to V3X Delay (Note 3) ● MIN TYP MAX 14.688 15.2 15.912 ● –10.608 –10.1 UNITS V % – 9.792 3.75 V kHz 3 4 10 0.4 0.77 1.2 ms Logic Inputs SHDN Pin Threshold MODE Pin Threshold Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Specification is guaranteed by design and not 100% tested in production. ● 1.6 V V Note 3: Measured from point at which VNEG crosses –5V to point at which C2– starts switching. Note 4: The LTC3450E is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. 3450fa 3 LTC3450 U W TYPICAL PERFOR A CE CHARACTERISTICS AVDD Efficiency vs VIN AVDD Efficiency vs VIN 100 100 L = 100µH L = 47µH 10mA 95 95 EFFICIENCY (%) EFFICIENCY (%) 5mA 90 2mA 85 80 10mA 90 5mA 85 2mA 80 75 75 70 (TA = 25°C unless otherwise noted) 70 1.5 2.0 2.5 3.0 3.5 VIN (V) 4.0 4.5 5.0 1.5 2.0 2.5 3.0 3.5 VIN (V) 4.5 4.0 3450 G03 3450 G02 No Load VIN Current in Blank Mode AVDD vs VIN and Load No Load VIN Current in Scan Mode 100 90 800 5.16 700 5.14 60 50 40 30 0mA 600 5.12 AVDD (V) VIN CURRENT (µA) VIN CURRENT (µA) 80 70 500 400 2.0 2.5 3.0 3.5 4.0 4.5 2.0 2.5 VIN (V) 3450 G04 3.5 4.0 4.5 5.04 5.0 5.5 2.0 2.5 3.0 3.5 VIN (V) 4.0 – 9.0 5.200 15.4 – 9.2 5.175 5.150 AVDD (V) – 9.4 VGL (V) 5.0 AVDD vs Temperature Figure 1 Circuit, 1mA Load VGL vs Load 15.2 4.5 3450 G06 15.6 – 9.6 – 9.8 5.125 5.100 5.075 14.8 – 10.0 14.6 14.4 1.5 3450 G05 VGH vs Load VGH (V) 3.0 VIN (V) 15.0 5mA 10mA 100 1.5 5.0 5.5 5.10 5.06 200 0 1.5 2mA 5.08 300 20 10 5.0 5.050 – 10.2 – 10.4 0 100 200 300 400 500 600 700 800 900 1000 VGH LOAD (µA) 3450 G07 5.025 0 100 200 300 400 500 600 700 800 900 1000 VGL LOAD (µA) 3450 G08 5.000 – 40 – 25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 3450 G09 3450fa 4 LTC3450 U W TYPICAL PERFOR A CE CHARACTERISTICS AVDD Ripple Voltage AVDD Load = 5mA AVDD Transient Response AVDD 100mV/DIV (AC) AVDD 5mV/DIV (AC) AVDD LOAD 5mA 5mA/DIV 1mA VIN = 3.6V C2 = 2.2µF 1µs/DIV 3450 G10 VIN = 3.6V C2 = 2.2µF 100µs/DIV 3450 G11 AVDD Turn-On Showing Inrush Current Limiting AVDD, VGL, VGH Turn-On and Turn-Off Sequence INDUCTOR CURRENT 100mA/DIV VGH 0 10V/DIV 0 AVDD 5V/DIV AVDD 2V/DIV 0 VGL 5V/DIV 0 VIN = 3.6V C2 = 2.2µF 2ms/DIV 3450 G12 VIN = 3.6V 20µs/DIV 3450 G13 3450fa 5 LTC3450 U U U PI FU CTIO S C3+ (Pin 1): Charge Pump Inverter Flying Capacitor Positive Node. The charge pump inverter flying capacitor is connected between C3+ and C3 –. The voltage on C3+ will alternate between GND and VINV at an approximate 50% duty cycle while the inverting charge pump is operating. Use a 10nF or larger X5R type ceramic capacitor for best results. SW (Pin 8): Switch Pin. Connect the inductor between SW and VIN. Keep PCB trace lengths as short and wide as possible to reduce EMI and voltage overshoot. If the inductor current falls to zero, the internal P-channel MOSFET synchronous rectifier is turned off to prevent reverse charging of the inductor and an internal switch connects SW to VIN to reduce EMI. C3 – (Pin 2): Charge Pump Inverter Flying Capacitor Negative Node. The charge pump inverter flying capacitor is connected between C3+ and C3 –. The voltage on C3 – will alternate between GND and VNEG at an approximate 50% duty cycle while the inverting charge pump is operating. Use a 10nF or larger X5R type ceramic capacitor for best results. GND (Pin 9): Signal and Power Ground for the LTC3450. Provide a short direct PCB path between GND and the output filter capacitor(s) on VOUT, V2X, V3X and VNEG. VNEG (Pin 3): Charge Pump Inverter Output. VNEG can be either – 5V or –10V depending on where VINV is connected. VNEG should be bypassed to GND with at 0.1µF or larger X5R type ceramic capacitor. VNEG can also be configured for –15V with two external low current Schottky diodes (see Applications section). MODE (Pin 4): Drive MODE high to force the LTC3450 into high power (scan) mode. Drive MODE low to force the LTC3450 into low power (blank) mode. The output voltages remain active with the MODE pin driven low but with reduced output current capability. MODE must be pulled up to VIN or higher on initial application of power in order for proper initialization to occur. SHDN (Pin 5): Master Shutdown Input for the LTC3450. Driving SHDN low disables all IC functions and reduces quiescent current from the battery to less than 2µA. Each generated output voltage is actively discharged to GND in shutdown through internal pull down devices. An optional RC network on SHDN provides a slower ramp up of the boost converter inductor current during startup (soft-start). VIN (Pin 6): Input Supply to the LTC3450. Connect VIN to a voltage source between 1.5V and 4.6V. Bypass VIN to GND with a 2.2µF X5R ceramic capacitor. VOUT (Pin 7): Main 5.1V Output of the Boost Regulator and Input to the Voltage Doubler Stage. Bypass VOUT with a low ESR, ESL ceramic capacitor (X5R type) between 2.2µF and 10µF. C1 – (Pin 10): Charge Pump Doubler Flying Capacitor Negative Node. The charge pump doubler flying capacitor is connected between C1 + and C1 –. The voltage on C1– will alternate between GND and VOUT at an approximate 50% duty cycle while the charge pump is operating. Use a 10nF or larger X5R type ceramic capacitor for best results. C1+ (Pin 11): Charge Pump Doubler Flying Capacitor Positive Node. The charge pump doubler flying capacitor is connected between C1+ and C1–. The voltage on C1+ will alternate between VOUT and V2X at an approximate 50% duty cycle while the charge pump is operating. Use a 10nF or larger X5R type ceramic capacitor for best results. V2X (Pin 12): Charge Pump Doubler Output. This output is 10.2V (nom) at no load and is capable of delivering up to 500µA to a load. V2X should be bypassed to GND with a 0.47µF X5R type ceramic capacitor. C2 – (Pin 13): Charge Pump Tripler Flying Capacitor Negative Node. The charge pump tripler flying capacitor is connected between C2 + and C2 –. The voltage on C2 – will alternate between GND and VOUT at an approximate 50% duty cycle while the charge pump is operating. Use a 10nF or larger X5R type ceramic capacitor for best results. C2 + (Pin 14): Charge Pump Tripler Flying Capacitor Positive Node. The charge pump tripler flying capacitor is connected between C2 + and C2 –. The voltage on C2 + will alternate between V2X and V3X at an approximate 50% duty cycle while the charge pump is operating. Use a 10nF or larger X5R type ceramic capacitor for best results. 3450fa 6 LTC3450 U U U PI FU CTIO S V3X (Pin 15): Charge Pump Tripler Output. This output is 15.3V (nom) at no load and is capable of delivering up to 500µA to a load. V3X should be bypassed to GND with a 0.1µF X5R type ceramic capacitor. Connecting VINV to 5V or 10V will generate –5V or –10V respectively on VNEG. See Applications section for –15V generation. Exposed Pad (Pin 17): The exposed pad must be connected to VNEG (Pin 3) on the PCB. Do not connect the exposed pad to GND. VINV (Pin 16): Positive Voltage Input for the Charge Pump Inverter. The charge pump inverter will generate a negative voltage corresponding to the voltage applied to VINV. W BLOCK DIAGRA L1 47µH VIN 1.5V TO 4.6V C1 2.2µF 8 VIN 6 SW SYNCHRONOUS PWM BOOST CONVERTER 7 AVDD 5.1V/10mA VOUT C2 2.2µF SHUTDOWN CHARGE PUMP DOUBLER IN OUT OSCILLATOR BLANK SCAN OFF ON MODE SHDN 10 12 C1+ C1– CF1 0.1µF V2X 10V C7 1µF SHUTDOWN 550kHz 69kHz CHARGE PUMP TRIPLER IN 4 5 11 OUT GLOBAL SHUTDOWN 14 13 15 C2 + C2 – CF2 0.1µF V3X VGH (3 × AVDD) 15V/500µA C8 0.47µF SHUTDOWN 16 CHARGE PUMP INVERTER IN OUT 1 2 3 VINV C3 + C3 – VNEG SHUTDOWN CF3 0.1µF VGL –10V/500µA C11 0.47µF 3450 TA01 9 GND 3450fa 7 LTC3450 U OPERATIO The LTC3450 is a highly integrated power converter intended for small TFT-LCD display modules. A fixed frequency, synchronous PWM boost regulator generates a low noise 5.1V, 10mA bias at greater than 90% efficiency from an input voltage of 1.5V to 4.6V. Three charge pump converters use the 5.1V output to generate 10V, 15V and –5V, –10V or –15V at load currents up to 500µA. Each converter is frequency synchronized to the main 550kHz (nominal) boost converter. The generated output voltages are internally sequenced to insure proper initialization of the LCD panel. A digital shutdown input rapidly discharges each generated output voltage to provide a near instantaneous turn-off of the LCD display. Boost Converter The synchronous boost converter utilizes current mode control and includes internally set control loop and slope compensation for optimized performance and simple design. Only three external components are required to complete the design of the 5.1V, 10mA boost converter. The high operation frequency produces very low output ripple and allows the use of small low profile inductors and tiny external ceramic capacitors. The boost converter also disconnects its output from VIN during shutdown to avoid loading the input power source. Softstart produces a controlled ramp of the converter input current during startup, reducing the burden on the input power source. Very low operating quiescent current and synchronous operation allow for greater than 90% conversion efficiency. The MODE input reduces the boost converter operating frequency by approximately 8x when driven high and reduces the output power capability of the boost converter. MODE is asserted when the polysilicon TFT-LCD display is in its extremely low power blank condition. The 15V 10V 5V –10V boost converter further reduces its quiescent current in this mode, delivering both lower input (battery) current drain and low noise operation. Charge Pumps The LTC3450 includes three separate charge pump converters which generate 10V, 15V and either –5V, –10V or –15V. Each output can deliver a maximum of 500µA. The charge pumps feature fixed frequency, open-loop operation for high efficiency and lowest noise performance. The charge pump converters operate at 1/8 the boost converter frequency and include internal charge transfer switches. Thus, each charge pump requires only two small external capacitors, one to transfer charge, and one for filtering. Similar to the boost converter, the charge pumps operating frequency reduces to approximately 4kHz in blank mode, maintaining low noise operation but at reduced output current capability. Output Sequencing Refer to the following text and Figure 1 for the LTC3450 power-up sequence. When input power is applied, the boost converter initializes and charges its output towards the final value of 5.1V. When the boost converter output reaches approximately 90% of its final value (4.5V), an internal 5V OK signal is asserted which allows the charge pump doubler to begin operation toward its final goal of 10V. Approximately 1ms later, the charge pump inverter begins operation toward its final goal of either –5V or –10V depending on the connection of the VINV input. When the –5V or –10V output (VNEG) reaches approximately 50% of its final value, a 4ms (nominal) timeout period begins. At the conclusion of the 4ms timeout period, the charge pump tripler is allowed to begin operation, which will eventually charge V3X to 15V (nominal). V3X V2X VOUT 1ms VNEG 4ms 3450 F01 Figure 1. Output Sequencing 3450fa 8 LTC3450 U U W U APPLICATIO S I FOR ATIO Inductor Selection Soft-Start Inductors in the range of 47µH to 100µH with saturation current (ISAT) ratings of at least 150mA are recommended for use with the LTC3450. Ferrite core materials are strongly recommended for their superior high frequency performance characteristics. A bobbin or toroid type core will reduce radiated noise. Inductors meeting these requirements are listed in Table 1. Soft-start operation provides a gradual increase in the current drawn from the input power source (usually a battery) during initial startup of the LTC3450, eliminating the inrush current which is typical in most boost converters. This reduces stress on the input power source, boost inductor and output capacitor, reduces voltage sag on the battery and increases battery life. The rate at which the input current will increase is set by two external components (RSS and CSS) connected to SHDN (refer to Figure 2). Upon initial application of power or release of a pull down switch on SHDN, the voltage on SHDN will increase relative to the R • C time constant or RSS • CSS. After one time constant SHDN will rise to approximately 63.2% of the voltage on VIN. From 0V to approximately 0.77V on SHDN, no switching will occur because the shutdown threshold is 0.77V (typ). From 0.77V to 1V the maximum switch pin current capability of the LTC3450 will gradually increase from near zero to the maximum current limit. An RSS in the range of 1MΩ to 10MΩ is recommended. If SHDN is driven high with a logic signal, the input current will gradually increase to its maximum value in approximately 50µs. Table 1. Recommended Inductors PART NUMBER L MAX DCR HEIGHT (µH) (Ω) (mm) VENDOR CLQ4D10-470 CLQ4D10-101 CMD4D08-470 47 100 47 1.28 3.15 1.6 DO1606-473 DO1606-104 DT1608-473 DT1608-104 47 100 47 100 1.1 2.3 0.34 1.1 LQH43MN470J03 47 LQH43MN101J03 100 1.5 2.5 2.6 Murata www.murata.com DU6629-470M DU6629-101M 0.64 1.27 2.92 Coev Magnetics www.circuitprotection.com 47 100 1.2 1.0 2.0 2.92 Sumida (847) 956-0666 www.sumida.com Coilcraft (847) 639-6400 www.coilcraft.com Capacitor Selection The boost converter requires two capacitors. The input capacitor should be an X5R type of at least 1µF. The VOUT capacitor should also be an X5R type between 2.2µF and 10µF. A larger capacitor (10µF) should be used if lower output ripple is desired or the output load required is close to the 10mA maximum. The charge pumps require flying capacitors of at least 0.1µF to obtain specified performance. Ceramic X5R types are strongly recommended for their low ESR and ESL and capacitance versus bias voltage stability. The filter capacitor on V2X should be at least 0.1µF. A 0.47µF or larger capacitor on V2X is recommended if VINV is connected to V2X. The filter capacitors on V3X and VNEG should be 0.1µF or larger. Please be certain that the capacitors used are rated for the maximum voltage with adequate safety margin. Refer to Table 2 for a listing of capacitor vendors. Table 2. Capacitor Vendor Information Supplier Phone Website AVX (803) 448-9411 www.avxcorp.com Murata (714) 852-2001 www.murata.com Taiyo Yuden (408) 573-4150 www.t-yuden.com VIN RSS 1M 5% 5 SHDN CSS 6.8nF 1ms SOFT-START WITH 3.6V VIN 3450 F02 Figure 2. Soft-Start Component Configuration Printed Circuit Board Layout Guidelines High speed operation of the LTC3450 demands careful attention to PCB layout. You will not get advertised performance with careless layout. Figure 3 shows the recommended component placement for a single layer PCB. A multilayer board with a separate ground plane is ideal but not absolutely necessary. 3450fa 9 LTC3450 U U W U APPLICATIO S I FOR ATIO V3X JUMPER VNEG MODE SHDN VOUT VIN GND NOTE: QFN PACKAGE EXPOSED PAD IS CONNECTED TO THE VNEG PIN. DO NOT CONNECT EXPOSED PAD TO GROUND 3450 F03 Figure 3. Suggested Layout U TYPICAL APPLICATIO 5.1V, –15V, 15V Triple Output TFT-LCD Supply VIN 1.5V TO 4.6V L1 47µH C1 2.2µF BLANK SCAN 8 6 4 7 SW VIN VOUT 11 C1 + 10 C1 – MODE V2X LTC3450 OFF ON 5 SHDN 9 14 C2 – 13 GND VINV VNEG C3 – C3 + 3 2 AVDD 5.1V/10mA CF1 0.1µF 12 C2 + V3X C2 2.2µF CF2 0.1µF 15 C4 0.47µF D1 VGH 15V/500µA 16 D2 C6 0.1µF 1 0.1µF CF3 0.1µF D1, D2: DUAL SCHOTTKY DIODE, PANASONIC MA704WKCT L1: SUMIDA CMD4D08-470 C5 0.1µF VGL –15V/500µA 3450 TA02 3450fa 10 LTC3450 U PACKAGE DESCRIPTIO UD Package 16-Lead Plastic QFN (3mm × 3mm) (Reference LTC DWG # 05-08-1691) 0.70 ±0.05 3.50 ± 0.05 1.45 ± 0.05 2.10 ± 0.05 (4 SIDES) PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 3.00 ± 0.10 (4 SIDES) BOTTOM VIEW—EXPOSED PAD 0.23 TYP R = 0.115 (4 SIDES) TYP 15 16 0.75 ± 0.05 PIN 1 TOP MARK (NOTE 6) 0.40 ± 0.10 1 1.45 ± 0.10 (4-SIDES) 2 (UD) QFN 0603 0.200 REF 0.00 – 0.05 NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WEED-2) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 0.25 ± 0.05 0.50 BSC 3450fa 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 11 LTC3450 U TYPICAL APPLICATIO 5.1V, – 5V, 15V Triple Output TFT-LCD Supply VIN 1.5V TO 4.6V L1 47µH 8 C1 2.2µF 6 BLANK SCAN 4 7 SW VIN VOUT 11 C1 + 10 C1 – MODE V2X LTC3450 OFF ON 5 SHDN 9 14 C2 – 13 GND VINV VNEG C3 – C3 + 3 2 AVDD 5.1V/10mA CF1 0.1µF 12 C2 + V3X C2 2.2µF CF2 0.1µF 15 C4 0.47µF VGH (3 × AVDD) 15V/500µA 16 C6 0.1µF 1 C5 0.1µF CF3 0.1µF VGL –5V/500µA L1: SUMIDA CMD4D08-470 3450 TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1310 1.5A ISW, 4.5MHz, High Efficiency Step-Up DC/DC Converter VIN: 2.75V to 18V, VOUT = 35V, IQ = 12mA, ISD = <1µA MSE Package LT1613 550mA ISW, 1.4MHz, High Efficiency Step-Up DC/DC Converter VIN: 0.9V to 10V, VOUT = 34V, IQ = 3mA, ISD = <1µA ThinSOT Package LT1615/LT1615-1 300mA/80mA ISW, Constant Off-Time, High Efficiency Step-Up DC/DC Converter VIN: 1.2V to 15V, VOUT = 34V, IQ = 20µA, ISD = <1µA ThinSOT Package LT1940 Dual Output 1.4A IOUT, Constant 1.1MHz, High Efficiency Step-Down DC/DC Converter VIN: 3V to 25V, VOUT (MIN) = 1.2V, IQ = 2.5mA, ISD = <1µA TSSOP-16E Package LT1944 Dual Output 350mA ISW, Constant Off-Time, High Efficiency Step-Up DC/DC Converter VIN: 1.2V to 15V, VOUT = 34V, IQ = 20µA, ISD = <1µA MS Package LT1944-1 Dual Output 150mA ISW, Constant Off-Time, High Efficiency Step-Up DC/DC Converter VIN: 1.2V to 15V, VOUT = 34V, IQ = 20µA, ISD = <1µA MS Package LT1945 Dual Output, Pos/Neg, 350mA ISW, Constant Off-Time, High Efficiency Step-Up DC/DC Converter VIN: 1.2V to 15V, VOUT = ±34V, IQ = 20µA, ISD = <1µA MS Package LT1946/LT1946A 1.5A ISW, 1.2MHz/2.7MHz, High Efficiency Step-Up DC/DC Converter VIN: 2.45V to 16V, VOUT = 34V, IQ = 3.2mA, ISD = <1µA MS8 Package LT1947 Triple Output ( for TFT-LCD) 1.1A ISW, 3MHz High Efficiency Step-Up DC/DC Converter VIN: 2.7V to 8V, VOUT = 34V, IQ = 9.5mA, ISD = <1µA MS Package LT1949/LT1949-1 550mA ISW, 600kHz/1.1MHz, High Efficiency Step-Up DC/DC Converter VIN: 1.5V to 12V, VOUT = 28V, IQ = 4.5mA, ISD = <25µA S8, MS8 Packages LTC3400/LTC3400B 600mA ISW, 1.2MHz, Synchronous Step-Up DC/DC Converter VIN: 0.85V to 5V, VOUT = 5V, IQ = 19µA/300µA, ISD = <1µA ThinSOT Package LTC3401 1A ISW, 3MHz, Synchronous Step-Up DC/DC Converter VIN: 0.5V to 5V, VOUT = 5V, IQ = 38µA, ISD = <1µA, MS Package LTC3402 2A ISW, 3MHz, Synchronous Step-Up DC/DC Converter VIN: 0.5V to 5V, VOUT = 5V, IQ = 38µA, ISD = <1µA, MS Package 3450fa 12 Linear Technology Corporation LT/TP 0205 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2003