LT3483/LT3483A Inverting Micropower DC/DC Converters with Schottky DESCRIPTION FEATURES Internal 40V Schottky Diode n One Resistor Feedback (Other Resistor Inside) n Internal 40V, 200mA/400mA Power Switch n Generates Regulated Negative Outputs to –38V n Low Quiescent Current: 40µA in Active Mode <1µA in Shutdown Mode n Low V CESAT Switch: 200mV at 150mA n Wide Input Range: 2.5V to 16V n Uses Small Surface Mount Components n Output Short-Circuit Protected n Available in a 6-Lead SOT-23 (LT3483 Only) and Low Profile 8-Lead DFN (2mm × 2mm × 0.75mm) Packages n APPLICATIONS n n n n n LCD Bias Handheld Computers Battery Backup Digital Cameras OLED Bias The LT®3483/LT3483A are micropower inverting DC/DC converters with integrated Schottky and one resistor feedback. The small package size, high level of integration and use of tiny surface mount components yield a solution size as small as 40mm2. The devices feature a quiescent current of only 40µA at no load, which further reduces to 0.1µA in shutdown. A current limited, fixed off-time control scheme conserves operating current, resulting in high efficiency over a broad range of load current. A precisely trimmed 10µA feedback current enables one resistor feedback and virtually eliminates feedback loading of the output. The 40V switch enables voltage outputs up to –38V to be generated without the use of costly transformers. The LT3483/LT3483A’s low 300ns off-time permits the use of tiny low profile inductors and capacitors to minimize footprint and cost in space-conscious portable applications. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7710700. TYPICAL APPLICATION 3.6V to –8V DC/DC Converter 75 0.22µF 10µH 10Ω VIN 4.7µF D LT3483 SHDN FB GND 5pF 806k EFFICIENCY 70 VOUT –8V 25mA 2.2µF 1000 VIN = 3.6V 100 65 10 POWER LOSS 60 1 POWER LOSS (mW) SW EFFICIENCY (%) VIN 3.6V Efficiency and Power Loss 3483 TA01a 55 0.1 1 10 LOAD CURRENT (mA) 0.1 100 3483 TA01b 3483fc 1 LT3483/LT3483A ABSOLUTE MAXIMUM RATINGS (Note 1) VIN Voltage................................................................ 16V SW Voltage............................................................... 40V D Voltage................................................................ –40V FB Voltage................................................................ 2.5V SHDN Voltage........................................................... 16V Operating Ambient Temperature Range (Note 2) LT3483E/LT3483AE...............................– 40°C to 85°C LT3483I/LT3483AI...............................– 40°C to 125°C Junction Temperature .......................................... 125°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) (TSOT-23 Package Only)................................... 300°C PIN CONFIGURATION TOP VIEW GND 2 GND 3 TOP VIEW 8 SHDN FB 1 9 SW 4 7 D SW 1 6 NC GND 2 5 VIN FB 3 6 VIN 5D 4 SHDN S6 PACKAGE 6-LEAD PLASTIC TSOT-23 TJMAX = 125°C, θJA = 192°C/W DC PACKAGE 8-LEAD (2mm × 2mm) PLASTIC DFN TJMAX = 125°C, θJA = 88.5°C/W EXPOSED PAD (PIN 9) IS GND ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3483EDC#PBF LT3483EDC#TRPBF LCYT 8-Lead (2mm 2mm) Plastic DFN –40°C to 85°C LT3483ES6#PBF LT3483ES6#TRPBF LTBKX 6-Lead Plastic TSOT-23 –40°C to 85°C LT3483AEDC#PBF LT3483AEDC#TRPBF LFXD 8-Lead (2mm 2mm) Plastic DFN –40°C to 85°C LT3483IDC#PBF LT3483IDC#TRPBF LCYT 8-Lead (2mm 2mm) Plastic DFN –40°C to 125°C LT3483IS6#PBF LT3483IS6#TRPBF LTBKX 6-Lead Plastic TSOT-23 –40°C to 125°C LT3483AIDC#PBF LT3483AIDC#TRPBF LFXD 8-Lead (2mm 2mm) Plastic DFN –40°C to 125°C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3483EDC LT3483EDC#TR LCYT 8-Lead (2mm 2mm) Plastic DFN –40°C to 85°C LT3483ES6 LT3483ES6#TR LTBKX 6-Lead Plastic TSOT-23 –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 3483fc 2 LT3483/LT3483A ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, VSHDN = 3.6V unless otherwise specified. PARAMETER CONDITIONS MIN VIN Operating Range TYP 2.5 VIN Undervoltage Lockout MAX UNITS 16 V 2 2.4 V FB Comparator Trip Voltage to GND (VFB) FB Falling ● 0 5 12 mV FB Output Current (Note 3) FB = VFB – 5mV ● –10.2 –10 –9.7 µA FB Comparator Hysteresis FB Rising Quiescent Current in Shutdown VSHDN = GND Quiescent Current (Not Switching) FB = –0.05V IFB Line Regulation 2.5V ≤ VIN ≤ 16V 10 40 Switch Off-Time mV 1 µA 50 µA 0.07 %/V 300 Switch Current Limit LT3483 LT3483A Switch VCESAT ISW = 150mA to GND Switch Leakage Current SW = 40V 170 340 200 400 ns 230 460 200 mV 1 D Pin Current Limit 350 Rectifier Leakage Current D = – 40V Rectifier Forward Drop ID = 150mA to GND SHDN Pin Current Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. µA mA 4 µA 0.64 SHDN Input Low Voltage SHDN Input High Voltage mA mA V 0.4 V 10 µA 1.5 V 6 Note 2: The LT3483E/LT3483AE are guaranteed to meet specifications from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LT3483I/LT3483AI are guaranteed to meet specifications over the –40°C to 125°C operating temperature range. Note 3: Current flows out of the pin. 3483fc 3 LT3483/LT3483A TYPICAL PERFORMANCE CHARACTERISTICS VFB Current 16 10.2 VFB Voltage Switch Off Time 400 350 VFB VOLTAGE (mV) VFB CURRENT (µA) 10.0 SWITCH OFF TIME (ns) 12 10.1 8 4 9.9 300 250 200 150 100 50 9.8 –50 –25 50 75 0 25 TEMPERATURE (°C) 100 125 0 –50 –25 50 75 0 25 TEMPERATURE (°C) 100 0 –50 –25 0 25 75 50 TEMPERATURE (°C) 3483 G02 3483 G01 125 3483 G03 440 CURRENT LIMIT (mA) 220 210 200 190 420 400 380 180 170 –50 –25 0 25 50 75 TEMPERATURE (°C) 100 360 –50 125 –25 50 75 0 25 TEMPERATURE (°C) 3483 G04 SHDN PIN BIAS CURRENT (µA) 10 40 30 20 10 –25 50 75 0 25 TEMPERATURE (°C) 125 SHDN Pin Bias Current Quiescent Current 0 –50 100 3483 G07 50 QUIESCENT CURRENT (µA) 100 Switch Current Limit (LT3483A) Switch Current Limit (LT3483) 230 SWITCH CURRENT LIMIT (mA) 125 100 125 3483 G05 TA = 25°C 8 6 4 2 0 0 8 4 12 SHDN PIN VOLTAGE (V) 16 3483 G06 3483fc 4 LT3483/LT3483A PIN FUNCTIONS (DFN/TSOT-23) FB (Pin 1/Pin 3): Feedback. Place resistor to negative output here. Set resistor value R1 = VOUT/10µA. D (Pin 7/Pin 5): Anode Terminal of Integrated Schottky Diode. Connect to negative terminal of transfer capacitor and external inductor L2 (flyback configuration) or to cathode of external Schottky diode (inverting charge pump configuration). GND (Pins 2, 3/Pin 2): Ground. For DFN package, tie both pin 2 and pin 3 together to ground. SW (Pin 4/Pin 1): Switch. Connect to external inductor L1 and positive terminal of transfer capacitor. SHDN (Pin 8/Pin 4): Shutdown. Connect to GND to turn device off. Connect to supply to turn device on. VIN (Pin 5/Pin 6): Input Supply. Must be locally bypassed with 1µF or greater. Exposed Pad (Pin 9/NA): GND. The exposed pad should be soldered to the PCB ground to achieve the rated thermal performance. NC (Pin 6/NA): No Internal Connection. BLOCK DIAGRAM L1A VIN L1B • 6 1 VIN 1.250V REFERENCE R1 3 FB COUT 5 SW D 300ns DELAY 125k VOUT VOUT • CFLY + S Q R Q Q1 D1 25mV + A3 A2 – + – A1 0.1Ω – 0.1Ω 20mV (LT3483) GND 2 OPTIONAL CHARGE PUMP CONFIGURATION. L1B REPLACED WITH: D2 D R2 3483 BD PIN NUMBERS CORRESPOND TO THE 6-PIN TSOT-23 PACKAGE VOUT 3483fc 5 LT3483/LT3483A OPERATION The LT3483/LT3483A use a constant off-time control scheme to provide high efficiency over a wide range of output currents. Operation can be best understood by referring to the Block Diagram. When the voltage at the FB pin is approximately 0V, comparator A3 disables most of the internal circuitry. Output current is then provided by external capacitor COUT, which slowly discharges until the voltage at the FB pin goes above the hysteresis point of A3. Typical hysteresis at the FB pin is 10mV. A3 then enables the internal circuitry, turns on power switch Q1, and the currents in external inductors L1A and L1B begin to ramp up. Once the switch current reaches 200mA (LT3483) or 400mA (LT3483A), comparator A1 resets the latch, which turns off Q1 after about 80ns. Inductor current flows through the internal Schottky D1 to GND, charging the flying capacitor. Once the 300ns off-time has elapsed, and internal diode current drops below 250mA (as detected by comparator A2), Q1 turns on again and ramps up to the switch current limit. This switching action continues until the output capacitor charge is replenished (until the FB pin decreases to 0V), then A3 turns off the internal circuitry and the cycle repeats. The inverting charge pump topology replaces L1B with the series combination D2 and R2. APPLICATIONS INFORMATION CHOOSING A REGULATOR TOPOLOGY Inverting Charge Pump The inverting charge pump regulator combines an inductor-based step-up with an inverting charge pump. This configuration usually provides the best size, efficiency and output ripple and is applicable where the magnitude of VOUT is greater than VIN. Negative outputs to –38V can be produced with the LT3483/LT3483A in this configuration. For cases where the magnitude of VOUT is less than or equal to VIN, use a 2-inductor or transformer configuration such as the inverting flyback. In the inverting charge pump configuration, a resistor is added in series with the Schottky diode between the negative output and the D pin of the LT3483/LT3483A. The purpose of this resistor is to smooth/reduce the current spike in the flying capacitor when the switch turns on. A 10Ω resistor works well for a Li+ to –8V application, and the impact to converter efficiency is less than 3%. The resistor values recommended in the applications circuits also limit the switch current during a short-circuit condition at the output. Inverting Flyback The inverting flyback regulator, shown in the –5V application circuit, uses a coupled inductor and is an excellent choice where the magnitude of the output is less than or equal to the supply voltage. The inverting flyback also performs well in a step-up/invert application, but it occupies more board space compared with the inverting charge pump. Also, the maximum |VOUT| using the flyback is less than can be obtained with the charge pump—it is reduced from 38V by the magnitudes of VIN and ringing at the switch node. Under a short-circuit condition at the output, a proprietary technique limits the switch current and prevents damage to the LT3483/LT3483A even with supply voltage as high as 16V. As an option, a 0.47µF capacitor may be added between terminals D and SW of LT3483/LT3483A to suppress ringing at SW. Inductor Selection Several recommended inductors that work well with the LT3483/LT3483A are listed in Table 1, although there are many other manufacturers and devices that can be used. Consult each manufacturer for more detailed information and for their entire selection of related parts. Many different sizes and shapes are available. For inverting charge pump regulators with input and output voltages below 7V, a 4.7µH or 6.8µH inductor is usually the best choice. For flyback regulators or for inverting charge pump regulators where the input or output voltage is greater than 7V, a 10µH inductor is usually the best choice. A larger value inductor can be used to slightly increase the available output current, but limit it to around twice the 3483fc 6 LT3483/LT3483A APPLICATIONS INFORMATION value recommended, as too large of an inductance will increase the output voltage ripple without providing much additional output current. to 4.7µF. The following formula is useful to estimate the output capacitor value needed: COUT = Table 1. Recommended Inductors PART MAX L IDC DCR HEIGHT (µH) (mA) (Ω) (mm) MANUFACTURER LQH2MCN4R7M02L LQH2MCN6R8M02L LQH2MCN100M02L 4.7 6.8 10 300 255 225 0.84 1.0 1.2 0.95 Murata www.murata.com SDQ12 Coupled Inductor 4.7 10 15 1.45 980 780 0.40 0.72 1.15 1.2 Cooper Electronics Tech www.cooperet.com LPD3015 Coupled Inductor 4.7 10 860 580 0.52 1.0 1.4 Coilcraft www.coilcraft.com where ISW = 0.25A (LT3483) or ISW = 0.5A (LT3483A) and ∆VOUT = 30mV. The flying capacitor in the inverting charge pump configuration ranges from 0.1µF to 0.47µF. Multiply the value predicted by the above equation for COUT by 1/10 to determine the value needed for the flying capacitor. Table 2. Recommended Ceramic Capacitor Manufacturers MANUFACTURER URL Capacitor Selection The small size and low ESR of ceramic capacitors make them ideal for LT3483/LT3483A applications. Use of X5R and X7R types is recommended because they retain their capacitance over wider voltage and temperature ranges than other dielectric types. Always verify the proper voltage rating. Table 2 shows a list of several ceramic capacitor manufacturers. Consult the manufacturers for more detailed information on their entire selection of ceramic capacitors. A 4.7µF ceramic bypass capacitor on the VIN pin is recommended where the distance to the power supply or battery could be more than a couple inches. Otherwise, a 1µF is adequate. A capacitor in parallel with feedback resistor R1 is recommended to reduce the output voltage ripple. Use a 5pF capacitor for the inverting charge pump, and a 22pF value for the inverting flyback or other dual inductor configurations. Output voltage ripple can be reduced to 20mV in some cases using this capacitor in combination with an appropriately selected output capacitor. The output capacitor is selected based on desired output voltage ripple. For low output voltage ripple in the inverting flyback configuration, use a 4.7µF to 10µF capacitor. The inverting charge pump utilizes values ranging from 0.22µF L •ISW 2 –VOUT • ∆VOUT AVX www.avxcorp.com Kemet www.kemet.com Murata www.murata.com Taiyo Yuden www.tyuden.com Setting the Output Voltage The output voltage is programmed using one feedback resistor according to the following formula: R1= – VOUT 10µA Inrush Current When VIN is increased from ground to operating voltage, an inrush current will flow through the input inductor and integrated Schottky diode to charge the flying capacitor. Conditions that increase inrush current include a larger, more abrupt voltage step at VIN, a larger flying capacitor, and an inductor with a low saturation current. While the internal diode is designed to handle such events, the inrush current should not be allowed to exceed 1.5A. For circuits that use flying capacitors within the recommended range and have input voltages less than 5V, inrush current remains low, posing no hazard to the device. In cases where there are large steps at VIN, inrush current should be measured to ensure operation within the limits of the device. 3483fc 7 LT3483/LT3483A APPLICATIONS INFORMATION Board Layout Considerations As with all switching regulators, careful attention must be given to the PCB board layout and component placement. Proper layout of the high frequency switching path is essential. The voltage signals of the SW and D pins have sharp rising and falling edges. Minimize the length and area of all traces connected to the SW and D pins. In particular, it is desirable to minimize the trace length to and from the flying capacitor, since current in this capacitor switches directions within a cycle. Always use a ground plane under the switching regulator to minimize interplane coupling. Suggested Layout (DFN) for Inverting Charge Pump Suggested Layout (SOT-23) for Inverting Charge Pump + GND VOUT CIN L1 R1 A COUT 8 1 2 3 GND 4 VIN SHDN K 1 6 6 2 5 5 3 4 7 9 CFLY CIN CFLY COUT VIN R1 L1 SHDN VOUT 3483 AI02 3483 AI01 TYPICAL APPLICATIONS 3.6V to –22V DC/DC Converter 1000 EFFICIENCY SW RS 30Ω 70 D LT3483 SHDN FB GND C1: TAIYO YUDEN LMK316BJ475MD C2: TAIYO YUDEN TMK107BJ104 (X5R) C3: TAIYO YUDEN TMK316BJ105MD D1: PHILIPS PMEG3002AEB L1: MURATA LQH2MCN100K02L 5pF R1 2.2M C3 1µF VOUT –22V 8mA 100 65 10 POWER LOSS 60 POWER LOSS (mW) VIN C1 4.7µF 75 D1 EFFICIENCY (%) VIN 3.6V C2 0.1µF L1 10µH 3.6V to –22V Converter Efficiency and Power Loss 1 3483 TA02a 55 0.1 1 0.1 10 LOAD CURRENT (mA) 3483 TA02b 3483fc 8 LT3483/LT3483A TYPICAL APPLICATIONS 3.6V to –8V DC/DC Converter Low Profile, Small Footprint VIN 3.6V C2 0.22µF L1 10µH VIN C1 4.7µF SW Switching Waveform D1 VOUT 20mV/DIV 10Ω VOUT –8V 25mA D LT3483 5pF SHDN FB GND C3 2.2µF R1 806k ISW 100mA/DIV 2µs/DIV C1: MURATA GRM219R61A475KE34B C2: TAIYO YUDEN LMK107BJ224 C3: MURATA GRM219R61C225KA88B D1: PHILIPS PMEG2005EB L1: MURATA LQH2MCN100K02L 3483 TA04b 3483 TA04a PACKAGE DESCRIPTION DC Package 8-Lead Plastic DFN (2mm × 2mm) (Reference LTC DWG # 05-08-1719 Rev A) R = 0.05 TYP 0.70 ±0.05 2.55 ±0.05 1.15 ±0.05 0.64 ±0.05 (2 SIDES) PACKAGE OUTLINE PIN 1 BAR TOP MARK (SEE NOTE 6) 2.00 ±0.10 (4 SIDES) R = 0.115 TYP 5 0.40 ± 0.10 0.64 ± 0.10 (2 SIDES) PIN 1 NOTCH R = 0.20 OR 0.25 × 45° CHAMFER (DC8) DFN 0409 REVA 4 0.25 ± 0.05 0.45 BSC 0.200 REF 1 0.23 ± 0.05 0.45 BSC 0.75 ±0.05 1.37 ±0.10 (2 SIDES) 1.37 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 8 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 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 3483fc 9 LT3483/LT3483A PACKAGE DESCRIPTION S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636 Rev B) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 1.90 BSC S6 TSOT-23 0302 REV B 3483fc 10 LT3483/LT3483A REVISION HISTORY (Revision history begins at Rev C) REV DATE DESCRIPTION C 09/10 Revised entire data sheet to add LTC3483A PAGE NUMBER 1-12 3483fc 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 LT3483/LT3483A TYPICAL APPLICATION –5V Step-Up/Step-Down Converter L1A 4.7µH VIN 2.5V TO 6V L1B 4.7µH • • SW VIN C1 4.7µF VOUT –5V D LT3483A 22pF FB SHDN GND C1: TAIYO YUDEN EMK316BJ475ML C2: TAIYO YUDEN JMK316BJ106ML L1A, L1B: COILTRONICS SDQ12-4R7 OR COILCRAFT LPD3015-472 Efficiency and Power Loss vs Load Current 210 VIN = 3.6V 60 180 50 150 40 120 30 90 20 60 10 30 0 0.1 C2 10µF 3483 TA03a Switching Waveforms POWER LOSS (mW) EFFICIENCY (%) 70 511k VOUT 50mV/DIV AC-COUPLED VSW 10V/DIV IL1A 0.5A/DIV IL1B 0.5A/DIV 2µs/DIV 3483 TA03c 0 100 1 10 LOAD CURRENT (mA) 3483 TA03b RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1617/LT1617-1 350mA/100mA (ISW) High Efficiency Micropower Inverting DC/DC Converter VIN: 1.2V to 15V, VOUT(MAX) = –34V, IQ = 20µA, ISD < 1µA ThinSOT Package LT1931/LT1931A 1A (ISW), 1.2MHz/2.2MHz, High Efficiency Micropower Inverting DC/DC Converter VIN: 2.6V to 16V, VOUT(MAX) = –34V, IQ = 5.8mA, ISD < 1µA ThinSOT Package LT1945 Dual Output, Boost/Inverter, 350mA (ISW), Constant Off-Time, High Efficiency Step-Up DC/DC Converter VIN: 1.2V to 15V, VOUT(MAX) = ±34V, IQ = 40µA, ISD < 1µA, MS10 Package LT3463 Dual Output, Boost/Inverter, 250mA (ISW), Constant Off-Time, High Efficiency Step-Up DC/DC Converter with Integrated Schottky Diodes VIN: 2.3V to 15V, VOUT(MAX) = ±40V, IQ = 40µA, ISD < 1µA DFN Package LT3464 85mA (ISW), High Efficiency Step-Up DC/DC Converter with Integrated Schottky and PNP Disconnect VIN: 2.3V to 10V, VOUT(MAX) = 34V, IQ = 25µA, ISD < 1µA ThinSOT Package LT3472 Boost (350mA) and Inverting (400mA) DC/DC Converter for CCD Bias with Integrated Schottkys VIN: 2.3V to 15V, VOUT(MAX) = ±40V, IQ = 2.8mA, ISD < 1µA DFN Package 3483fc 12 Linear Technology Corporation LT 0910 REV C • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2004