DEMO MANUAL DC1878A LTC3789EGN 8V to 75VIN Buck/Boost DC/DC Converter Description Demonstration circuit 1878A features the LTC3789EGN, a high efficiency switching step-up/down controller. The input range has been extended to 75V by using a LTC44445 MOSFET driver on the input side. The minimum input voltage is 8V. The output voltage is 12V. The board is capable of delivering up to 5A of output current over the input voltage range. The LTC3789EGN is a high performance switching regulator controller designed to regulate the output using input voltages above, below or equal to the output voltage. Synchronous operation provides very high efficiency, up to 97%. Constant frequency current mode architecture allows phase-lockable frequency from 200kHz to 600kHz. Performance Summary PARAMETER An accurate output current limit provides support for battery charging. A wide input and output range with smooth transfer function through all operating modes makes the product ideal for automotive, telecom and battery systems. The MODE/PLLIN pin can select between pulse-skipping mode and forced continuous mode operation and allows the IC to be synchronized to an external clock. A power good output pin indicates when the output is within 7.5% of its set point. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. (TA = 25°C) CONDITIONS Minimum Input Voltage VALUE 8V Maximum Input Voltage 75V Output Voltage VOUT Regulation VIN = 8V – 75V, IOUT = 0A – 5A 12V ± 2% Maximum Continuous Output Current Some Airflow May Be Needed at High Input Voltage and Continuous Full Load 5A Default Operating Frequency R3 = 0Ω 200kHz External Clock Synchronous Frequency Range Efficiency Load Transient 200kHz – 600kHz VIN = 8V to 75V, IOUT = 5A 90.5% to 97%. See Figures 3 and 6 See Figure 5 dc1878af 1 DEMO MANUAL DC1878A Quick Start Procedure Demonstration circuit 1878A is easy to set up to evaluate the performance of the LTC3789EGN. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below. 1.With power off, connect the input supply, load and meters as shown in Figure 1. Preset the load to 0A and VIN supply to 0V. 2.Set the current limit of the input supply high enough so that the bench supply does not go into current limit mode. Figure 2 shows input current as a function of input voltage, at full load. Input current can reach 8A at 8V input voltage. 3.Place jumper in the following position: JP1 RUN ON 4. Turn on the power at the input. Increase VIN to between 8V and 75V. The circuit will start and the output voltage will regulate at 12V ±2%. The current draw at no load is typically 18mA to 37mA depending on the input voltage. Auxiliary Supply The demo board DC1878A has a LTC3803 based flyback converter to provide 8V/50mA bias voltage for LTC3789 and LTC4444-5. The snubber for the flyback primary winding provides a voltage that is above the input voltage. A transistor Q9 is used to provide a small current source to the top gate driver of LTC4444-5 so that 100% duty cycle is possible. If this current source is not used, for example if the flyback auxiliary supply is replaced by an external 6V to 12V supply, it is necessary to connect BOOST1 to 3.0V (add 3V Zener diode D11, R11 = 1k, remove R16) and use a level shift circuit (add D3 = BAS16, R12 = 1k, remove R6) between TG1 and TINP (due to the 3.25V maximum threshold for TINP). By setting BOOST1 to 3.0V, the LTC3789 will issue narrow refresh pulses on BG1 which keeps the top gate driver powered also in BOOST mode. In addition, DC1878A demo board has layout for an optional bias supply intended for a future monolithic high voltage buck regulator. Additional information will be provided when this part is released. 5. Apply load and observe output voltage regulation, ripple voltage, efficiency and other parameters. Efficiency and power loss at full load is shown in Figure 3. Continuous operation with full power and high input voltage may require some airflow. dc1878af 2 DEMO MANUAL DC1878A quick start procedure Figure 1. Proper Measurement Equipment Setup dc1878af 3 DEMO MANUAL DC1878A CURRENT (A) quick start procedure 10 9 8 7 6 5 4 3 2 1 0 IOUT IIN 0 10 20 30 40 50 60 70 80 INPUT VOLTAGE (V) 100 8 98 7 η% 96 6 94 5 92 4 90 3 PLOSS 88 2 86 84 POWER LOSS (W) EFFICIENCY (%) Figure 2. Input Current at Full Load (12V at 5A Output) 1 0 10 20 30 40 50 60 70 80 0 INPUT VOLTAGE (V) Figure 3. Efficiency and Power Loss at Full Load. The Power Loss is Highest at High Input Voltage Due to the Switching Losses and Drops as Input Voltage Decreases, Until the Inductor Current Starts to Increase as the Circuit Enters Boost Mode Below 10V Input Voltage dc1878af 4 DEMO MANUAL DC1878A quick start procedure 100mV Figure 4. Output Ripple Voltage Measured Across COUT1 dc1878af 5 DEMO MANUAL DC1878A quick start procedure Figure 5. Load Transient Response dc1878af 6 DEMO MANUAL DC1878A quick start procedure 100 99 98 97 96 EFFICIENCY (%) 95 94 8V 12V 16V 24V 36V 48V 60V 72V 76V 93 92 91 90 89 88 87 86 85 0 1 2 3 4 5 LOAD (A) Figure 6. Efficiency at Various Input Voltages dc1878af 7 DEMO MANUAL DC1878A quick start procedure 14 12 VOUT (V) 10 8 6 4 2 0 0 1 2 3 4 5 6 LOAD (A) Figure 7. Output Current Limit (The Easiest Way to Do This Test Is with an Active Load in Voltage Mode) dc1878af 8 DEMO MANUAL DC1878A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 1 1 CC1 CAP, 0603 470pF 10% 50V NPO AVX 06035A471KAT 2 1 CC2 CAP, 0603 0.01µF 10% 50V X7R AVX 06035C103KAT2A 3 0 CF1, C31, C32, C37, CF CAP, 0603 OPTION OPTION 4 0 CIN1, COUT11, CIN11, COUT21, CIN21 CAP, OPTION OPTION 5 1 CIN2 CAP, 150µF 100V ELEC SUN ELEC. 100ME150AX 6 1 COUT1 CAP, 330µF 20% 16V OSCON SUN ELECT. 16SEP330M+T 7 0 COUT2 CAP, 330µF 20% 16V OSCON OPTION SUN ELECT. 16SEP330M+T OPTION 8 1 CSS CAP, 0603 4700pF 10% 50V X7R AVX 06035C472KAT2A 9 2 C1,C2 CAP, 1210 22µF 10% 25V X5R MURATA GRM32ER61E226KE15L 10 0 C3, C21, C23, C25, C27, C28 CAP, 1210 OPTION OPTION 11 1 C4 CAP, 0603 0.22µF 10% 25V X7R AVX 06033C224KAT2A 12 3 C5, C6, C9 CAP, 1210 2.2µF 10% 100V X7R MURATA GRM32ER72A225KA35L 13 0 C7, C8, C29, C30, C33 CAP, 1210 2.2µF 10% 100V X7R OPTION MURATA GRM32ER72A225KA35L OPTION 14 1 C10 CAP, 0603 4.7µF 20% 6.3V X5R TAIYO YUDEN JMK 107 BJ457MA-T 15 1 C11 CAP, 0603 33pF 10% 50V NPO AVX 06035A330KAT2A 16 0 C12, C13 CAP, 1206 OPTION OPTION 17 3 C14, C16, C26 CAP, 0603 0.1µF 10% 50V X7R AVX 06035C104KAT2A 18 1 C15 CAP, 0805 1µF 20% 16V X5R AVX 0805YD105MAT2A 19 1 C17 CAP, 0603 1nF 10% 50V COG AVX 06035A102KAT2A 20 2 C18, C20 CAP, 1206 10µF 20% 10V X7R AVX 1206ZC106MAT2A 21 2 C19, C24 CAP, 0603 1µF 20% 16V X7R AVX 0603YC105MAT2A 22 1 C22 CAP, 0603 0.22µF 20% 16V X7R TAIYO YUDEN EMK107BJ224MA 23 0 C34 CAP, 0603 0.1µF 10% 50V X7R OPTION AVX 06035C104KAT2A OPTION 24 0 C35 CAP, 0603 47nF 10% 25V X7R OPTION AVX 06033C473KAT2A OPTION 25 0 C36 CAP, 1210 47µF 10% 10V X7R OPTION MURATA GRM32ER71A476KE15L OPTION 26 3 D2, D9, D12 DIODE, SWITCHING, 200mW, SOT23 DIODES INC. BAS16 27 0 D3, D10, D11 DIODE, OPTION SOT-23 OPTION 28 2 D4, D14 DIODE, SWITCHING, 350mW, SOT23 DIODES INC. BAS21 29 1 D5 DIODE, SCHOTTKY DIODES INC. B1100 30 1 D6 DIODE, SCHOTTKY, SMA DIODES INC. B240A-13-F 31 1 D7 DIODE, SCHOTTKY DIODES INC. DFLS160 32 1 D8 DIODE, ZENER, 5.1V, SOT23 DIODES INC. BZX84C5V1-7-F 33 1 D13 DIODE, ZENER, 6.8V, SOT23 DIODES INC. BZX84C6V8 34 1 D15 DIODE, 1.0A HIGH VOLTAGE SCHOTTKY BARRIER RECTIFIER DIODES INC. DFLS1100 35 1 JP1 HEADER, SINGLE ROW, 3 PIN, 2mm SAMTEC TMM103-02-L-S 36 0 JP2 HEADER, SINGLE ROW, 3 PIN, 2mm OPTION SAMTEC TMM103-02-L-S OPTION 37 4 J1, J2, J3, J4 JACK, BANANA KEYSTONE 575-4 38 1 L1 IND, 19µH PULSE PA2050.193NL 39 0 L2 IND, 22µH OPTION TDK VLF10040T-220M2R5 OPTION 40 4 MH1, MH2, MH3, MH4 STANDOFF, SNAP ON KEYSTONE_8834 dc1878af 9 DEMO MANUAL DC1878A parts list ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 41 1 Q1 XSTR, FDC2512 N-CHANNEL MOSFET FAIRCHILD FDC2512 42 1 Q2 XSTR, MOSFET N-CHANNEL 100V VISHAY SiR870DP 43 2 Q3, Q5 XSTR, MOSFET N-CHANNEL 20V VISHAY SiR496DP-T1-GE3 44 1 Q4 XSTR, MOSFET N-CHANNEL 100V VISHAY SiR882DP 45 1 Q6 XSTR, SMALL SIGNAL NPN SOT-23 DIODES INC. MMBTA42-7 46 0 Q8, Q13 XSTR, MOSFET N-CHANNEL 20V OPTION VISHAY SiR496DP-T1-GE3 OPTION 47 1 Q9 XSTR, SMALL SIGNAL PNP SOT-23 DIODES INC. MMBTA92-7 48 0 Q14, Q15 XSTR, MOSFET N-CHANNEL 100V OPTION VISHAY SiR882DP OPTION 49 1 RC RES, 0603 14.7kΩ 1% 1/10W VISHAY CRCW060314K7FKEA 50 1 RFB1 RES, 0603 113kΩ 1% 1/10W VISHAY CRCW0603113KFKEA 51 1 RFB2 RES, 0603 8.06kΩ 1% 1/10W VISHAY CRCW06038K06FKEA 52 1 R1 RES, 0805 5.6Ω 1% 1/10W VISHAY CRCW08055R60FKNEA 53 1 R2 RES, 3720 0.01Ω 2% 1W THIN FILM RECH. RL3720WT-R010-F 54 3 R3, R4, R44 RES, 0603 100Ω 5% 1/10W VISHAY CRCW0603100RJNEA 55 1 R5 RES, 0805 4.7Ω 1% 1/10W VISHAY CRCW08054R70FKNEA 56 8 R6, R11, R16, R21, R25, R27, R32, R50 RES, 0603 0Ω JUMPER VISHAY CRCW06030000Z0EA 57 3 R7, R15, R20 RES, 0603 100kΩ 1% 1/10W VISHAY CRCW0603100KFKEA 58 2 R8, R26 RES, 0603 10Ω 5% 1/10W VISHAY CRCW060310R0JNEA 59 2 R9, R10 RES, 0603 1kΩ 1% 1/10W VISHAY CRCW06031K00FKEA 60 0 R12, R19, R22, R23, R33-R36, R51 RES, 0603 OPTION OPTION 61 2 R13, R14 RES, 0603 154kΩ 1% 1/10W VISHAY CRCW0603154KFKEA 62 0 R17 RES, 0805 0Ω JUMPER OPTION VISHAY CRCW08050000Z0EA OPTION 63 1 R18 RES, 3720 0.012Ω 2% 1W THIN FILM TECH. RL3720WT-R012-F 64 1 R24 RES, 0603 10kΩ 1% 1/10W VISHAY CRCW060310K0FKEA 65 0 R28, R29 RES, 1206 OPTION OPTION 66 1 R30 RES, 1206 64.9kΩ 1% 1/10W VISHAY CRCW120664K9FKEA 67 1 R31 RES, 0603 12.1kΩ 1% 1/10W VISHAY CRCW060312K1FKEA 68 1 R37 RES, 0603 14kΩ 1% 1/10W VISHAY CRCW060314K0FKEA 69 1 R38 RES, 1206 220kΩ 5% 1/4W VISHAY CRCW1206220KJNEA 70 1 R39 RES, 1206 100kΩ 1% 1/10W VISHAY CRCW1206100KFKEA 71 1 R40 RES, 0603 22.1kΩ 1% 1/10W YAGEO RC0603FR-0722KIL 72 1 R41 RES, 0603 1.58kΩ 1% 1/10W VISHAY CRCW06031K58FKEA 73 1 R42 RES, 0603 10Ω 1% 1/8W VISHAY CRCW060310R0FKEA 74 1 R43 RES, 1206 0.30Ω 1% 1/8W IRC LR1206LF-01-R300-F 75 1 R45 RES, 0603 24.9kΩ 1% 1/10W NIC NRC06F2492TRF 76 2 R46, R47 RES, 0603 33.2kΩ 1% 1/10W VISHAY CRCW060333K2FKEA 77 1 R48 RES, 0603 5.6kΩ 1% 1/10W VISHAY CRCW06035K49FKEA 78 0 R49, R55, R56 RES, 0603 0Ω JUMPER OPTION VISHAY CRCW06030000Z0EA OPTION 79 0 R52 RES, 0603 2MΩ 1% 1/10W OPTION VISHAY CRCW06032M00FKEA OPTION 80 0 R53 RES, 0603 102kΩ 1% 1/10W OPTION VISHAY CRCW0603102KFKEA OPTION 81 0 R54 RES, 0603 11.3kΩ 1% 1/10W OPTION VISHAY CRCW060311K3FKEA OPTION 82 4 TP1, TP2, TP3, TP7 TURRET MILL-MAX 2308-2-00-80-00-00-07-0 dc1878af 10 DEMO MANUAL DC1878A parts list ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 83 7 TP4, TP5, TP8, TP10, TP11-TP13 TURRET MILL-MAX 2501-2-00-80-00-00-07-0 84 1 T1 XFMR, LOW POWER FLYBACK TRANS PULSE PA0648NL 85 1 U1 IC, VOLT REG. LINEAR TECH. LTC3789EGN 86 1 U2 IC, HIGH VOLTAGE SYNCHRONOUS N-CHANNEL MOSFET DRIVER LINEAR TECH. LTC4444EMS8E-5 87 1 U3 IC, CONSTANT FREQ. CURRENT MODE FLYBACK DC/DC CONTROLLER LINEAR TECH. LTC3803ES6-5 88 0 U4 IC, STEP-DOWN CONVERTER, MSE16(12), LINEAR TECH. FUTURE PRODUCT 4mm × 3mm OPTION 89 1 XJP1 SHUNT SAMTEC 2SN-BK-G 90 0 XJP2 SHUNT OPTION SAMTEC 2SN-BK-G OPTION dc1878af 11 A B C D EXTVCC PLLIN SS SGND PGOOD INTVCC TP12 OFF ON VIN TP10 TP5 TP11 TP4 TP8 2 JP1 3 64.9k 1206 RUN 1 R30 5 R31 12.1K D8 BZX84C5V1 R24 10K 4700pF CSS R7 100k INTVCC RFB2 R25 0 R22 OPT INTVCC OPT 8.06K CF1 1k 1% R10 0.01uF CC2 VIN VOUT R14 154k 1% R20 100k 1% C11 33pF R35 OPT R13 154k 1% 0 R21 4 OPT R34 4.7uF C10 14.7k 1% RC CC1 470pF 1k 1% CF OPT R9 R15 100k 1% RFB1 113K VOS+ 4 CIRCUITRY ON THIS SIDE MUST CONNECT TO SIGNAL GND GROUNDPLANE NC SW2 TG2 BOOST2 BG2 EXTVCC INTVCC VIN BG1 PGND1 BOOST1 TG1 SW1 PGOOD <------ IOSENSE- IOSENSE+ ILIM VOUTSNS VINSNS RUN FREQ MODE/PLLIN SGND ITH SENSE1- SENSE1+ SS VFB R36 OPT 14 13 12 11 10 9 8 7 6 5 4 3 2 1 U1 LTC3789EGN OPT D11 OPT D3 0 OPT R3 R4 100 100 R33 OPT R26 10 C18 16V R50 0 C22 0.22uF 3 R1 5.6 0805 BAS16 D2 1 0.1uF C16 10uF 1206 D7 DFLS160 3 D10 VOUT 1uF C24 0.1uF OPT INTVCC R11 INTVCC 1 8V R12 VAUX INTVCC C14 3 R6 0 CIRCUITRY ON THIS SIDE MUST CONNECT TO POWER GND GROUNDPLANE ------> 15 16 17 18 19 20 21 22 23 24 25 26 27 28 TP13 VAUX 3 3 D9 BAS16 BAS21 U2 1 4 3 2 1 TS TG BG2 BG1 BG NC VCC BOOST BINP TINP C4 SW1 CS 0.22uF 16V Q4 SiR882DP 5 6 7 8 D5 B1100 C12 OPT 1206 R28 OPT 1206 C9 2.2uF 100V 1210 R18 0.012 2% VIN R5 4.7 0805 TG1 Q2 SiR870DP SHT 2 B LTC4444EMS8E-5 C15 1uF 16V 0805 D4 GND 9 1 12 3 5 2 R19 OPT R32 0 Q5 SiR496DP 19uH L1 SW2 TG2 R29 OPT 1206 C13 OPT 1206 2 0.010 2% VOUT C30 OPT 1210 + CIN1 OPT + + CS SW2 TG2 BG2 BG1 SW1 TG1 C25 OPT 1210 C27 OPT 1210 VOUT GND GND VIN 8V - 75V VIN+ TAGE B. APPROVED CS SW2 TG2 BG2 BG1 SW1 SHT 2 VOS- GND VOS+ 12V / 5A MAX TG1 C28 OPT 1210 TP1 J2 TP2 VOS+ J1 TP7 J4 J3 TP3 CIN2 150uF 100V R8 10 DATE 10/28/11 1 DEMO CIRCUIT 1878A LTC3789EGN 8V - 75V VIN BUCK-BOOST DC/DC CONVERTER TECHNOLOGY C21 OPT 1210 VOUT1 C3 C23 COUT1 COUT2 OPT OPT 330uF 330uF 16V 1210 1210 16V OPT C29 OPT 1210 + PRODUTION 1 REVISION HISTORY DESCRIPTION Tuesday, January 17, 2012 REV C8 OPT 1210 R2 ECO C7 OPT 1210 C1 22uF 25V 1210 D6 B240A 25V 1210 C2 22uF VOUT1 C6 2.2uF 100V 1210 SiR496DP Q3 C5 2.2uF 100V 1210 2 A B C D DEMO MANUAL DC1878A Schematic Diagram dc1878af 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. A B C OPT C17 1 14k 1% 1.58k 1% R37 SHT 1 CS BG1 SW1 TG1 OPTIONAL PARTS VAUX1 R41 5 3 22.1k 1% 1000pF 2 R40 C31 CS SW1 Q15 SiR882DP BG1 TG1 G VIN SNS VCC Q14 SiR870DP VFB=0.8V GND ITH/RUN U3 LTC3803ES6-5 4 5 6 R44 100 SHT 1 BG2 SW2 TG2 5.6k 1% R48 D12 BAS16 Q8 3 SW2 Q13 SiR496DP BG2 VIN Q1 FDC2512 R43 0.30 1% 1206 VOUT1 4 SiR496DP TG2 1uF 16V C19 R38 220k 1206 1 VIN 2 1 3 VAUX1 6 D C20 10uF 10V 1206 4 8 1 5 7 T1 2 PA0648NL VIN 0.1uF C26 R42 10 1% BAS21 R46 33.2k 1% R45 24.9k 1% 33.2k 1% R47 3 0 R16 Q9 MMBTA92-7 CLAMPING SNUBBER/ 400uA SUPPLY D14 DFLS1100 R27 0 D15 1 3 5 4 VAUX R49 0 R51 OPT R52 2M 1% VIN BIAS RUN ON JP2 OFF R23 OPT OPTIONAL BIAS SUPPY B SHT 1 1 AUXILIARY SUPPLY 8V / 50mA 2 VIN D13 R39 BZX84C6V8 100k 1% Q6 1206 MMBTA42-7 C32 OPT 11 5 12 14 ISET FBO OV RUN C33 3 VIN 2.2uF 100V 1210 2 SS VPRG2 VPRG1 VFB SW U4 FUTURE LTCXXXX NC 2 4 NC 13 NC 15 NC 3 2 GND 3 8 16 GND 4 GND 17 5 10 6 7 9 1 C35 47nF 0 R56 0 R55 R54 11.3k 1% R53 102k 1% C37 OPT C36 47uF 10V 1210 C34 0.1uF R17 OPT 0805 VAUX Thursday, December 08, 2011 1 DEMO CIRCUIT 1878A LTC3789EGN 8V - 75V VIN BUCK-BOOST DC/DC CONVERTER TECHNOLOGY TDK VLF10040 22uH L2 1 A B C D DEMO MANUAL DC1878A Schematic Diagram dc1878af 13 DEMO MANUAL DC1878A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc1878af 14 Linear Technology Corporation LT 0312 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2012