DEMO MANUAL DC2132A LT3081, LT8612, LT3092 24V 3A Constant Voltage, Constant Current Bench Supply Description DC2132A is a 24V 3A constant voltage, constant current bench supply. It regulates any output voltage from 0V to 24V and any output current from 0A to 3A. It runs from 10V to 40V input although the output voltage should remain 5V or more below the input voltage. The LT®8612 step-down regulator is followed by two parallel LT®3081 linear regulators for a combination of low output ripple, high bandwidth and easy-to-adjust output voltage and current limits. The LT8612 is configured in pulseskipping operation and its output voltage is regulated to roughly 1.7V above the output voltage of the LT3081. The LT3081 SET and ILIM pins are connected to potentiometers that act as adjustable knobs on the PCB for voltage and current limit respectively. The LT 3092 current source is used to deliver current to power the adjustable resistance of the voltage limit knob (potentiometer). That voltage directly sets the output voltage of the LT3081. The maximum output voltage can be set to three settings: 24V, 15V and 5.5V with the shunt position on JP1. The setting should be changed according to the choice of input voltage. A 36V, 24V, or 12V AC/DC converter can be used to power this supply (as well as any DC voltage between 10V and 40V.) If input voltage limits maximum output voltage, then it is recommended to adjust the maximum output voltage to get the full range of the adjustment knob for best resolution. ® DC2132A operates to 0V and 0A. It is short-circuit proof. With very small output capacitance, the short-circuit spike is hundreds of times shorter in duration than commonly used and expensive laboratory bench power supplies. With the LT3081s in parallel on the output of this supply, small output capacitance makes this possible. Only 30μF is needed on the output of each LT3081. The LT3081 provides very low output ripple and short-circuit robustness. An ON/OFF switch turns the converter and its components on and off. A green indicator LED tells if the circuit is on or not. Two TEMP turrets and an IMON turret provide readouts of the LT3081 IC temperatures and the bench supply output current. The LT3081, LT8612, and LT3092 data sheets give complete descriptions of the devices, operation and applications information. The data sheet must be read in conjunction with this demo manual for DC2132A. The LT3081ER is assembled in a 7-lead plastic DD (R) package with a thermally enhanced VOUT tab and with θJA = 15ºC/W. Proper board layout is essential for maximum thermal performance. See the the Layout Considerations section in the data sheet. Design files for this circuit board are available at http://www.linear.com/demo/DC2132A L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. dc2132af 1 DEMO MANUAL DC2132A Performance Summary PARAMETER Specifications are at TA = 25°C CONDITIONS VIN Input Voltage Range MIN TYP 10 LT8612 Switching Frequency R20 = 60.4k VOUT Range (Set by VLIMIT) VIN = 36V, JP1 Set to 24V IOUT Range (Set by ILIMIT) MAX 40 700 UNITS V kHz 0 25 V 0 3.1 A Quiescent Current VIN = 36V VOUT = 24V, No Load 31 mA Typical Efficiency with 3A Output VIN = 36V, VOUT = 24V VIN = 12V, VOUT = 5V VIN = 12V, VOUT = 3.3V 90 71 62 % % % LT3081 Input-to-Output Voltage Drop R37 = 1.00k, R21 = R38 = 100k, R18 = 4.99k 1.7 V VOUT AC Ripple VIN = 36V, VOUT = 24V, IOUT = 3.0A ~10 mVP-P Minimum Load 0 mA Board Photo 2 dc2132af DEMO MANUAL DC2132A Quick Start Procedure DC2132A is easy to set up to evaluate the performance of the LT3081 and LT8612. Follow the procedure below: 1.Set the ON/OFF switch to OFF to disable switching. 2.With power off, connect the input power supply to the VIN and GND terminals. Make sure that the VIN DC input voltage will not exceed 40V. Be careful for hot plug transients above 40V. 3.The DC2132A bench supply is robust and can be turned on with or without a load. If the load is too big, DC2132A will limit its output. If there is a short-circuit on the output, DC2132A will run through the short safely and will limit its current to its ILIMIT setting. 4.Observe the output voltage and current as well as the temperature of the ICs. Figure 1. Test Procedure Setup Drawing for DC2132A dc2132af 3 DEMO MANUAL DC2132A Quick Start Procedure 100 36VIN EFFICIENCY 90 100 7 90 6 3 50 24VOUT 18VOUT 12VOUT 5VOUT 3.3VOUT POWER LOSS 40 30 0 0.5 1 1.5 2 IOUT (A) 2.5 3 2 EFFICIENCY (%) 4 60 80 7 6 EFFICIENCY 5 70 4 60 3 POWER LOSS 50 1 40 0 3.5 30 DC2132A F02a 8 12VIN 5VOUT 3.3VOUT 1.8VOUT POWER LOSS (W) 5 70 POWER LOSS (W) 80 EFFICIENCY (%) 8 2 1 0 0.5 1 1.5 2 IOUT (A) 2.5 3 0 3.5 DC2132A F02b Figure 2. DC2132A Efficiency and Power Loss at Different Voltage and Current 4 dc2132af DEMO MANUAL DC2132A Quick Start Procedure 3A 1A IOUT VOUT (AC) Figure 3. DC2132A 1A to 3A Transient Response 36VIN, 24VOUT VOUT (AC) LT8612 SW Figure 4. DC2132A Output Voltage Ripple dc2132af 5 DEMO MANUAL DC2132A Quick Start Procedure + VOUT – COUT GND Figure 5. DC2132A Output Voltage Ripple Measurement Method 6 dc2132af DEMO MANUAL DC2132A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 12 C3, C5, C6, C7, C9, C10, C11, CAP., X5R 10µF 50V 20% 1210 C19, C20, C22, C27, C28 TAIYO YUDEN UMK325BJ106MM-T 2 1 C4 CAP., X5R 0.1µF 50V 10% 0603 TDK C1608X5R1H104K 3 1 C12 CAP., X5R 1µF 50V 10% 0603 TDK C1608X5R1H105K 4 1 C13 CAP., NPO 1nF 25V 5% 0603 AVX 06033A102JAT2A 5 1 C14 CAP., X5R 1µF 25V 10% 0603 TDK C1608X5R1E105K 6 1 C15 CAP., X7R 0.1µF 25V 10% 0603 AVX 06033C104KAT2A 7 2 C17, C23 CAP., X7R 0.01µF 100V 10% 0603 AVX 06031C103KAT2A 8 1 C21 CAP., X7R 1µF 50V 10% 0805 MURATA GRM21BR71H105KA12L 9 1 C25 CAP., X7R 1µF 16V 10% 0603 MURATA GCM188R71C105KA64L 10 1 C26 CAP., X5R 10µF 6.3V 20% 0603 TDK C1608X5R0J106M 11 1 C29 CAP., ALUM. ELECT. 100µF 35V ±20% F80 NIPPON CHEMI-CON EMZA350ADA101MF80G 12 1 D5 SCHOTTKY DIODE, 1A/40V SMA DIODES/ZETEX B140-13-F 13 1 L1 INDUCTOR, 5.5µH WÜRTH ELEKTRONIK 744325550 14 1 L2 INDUCTOR, 470µH ±10% 1210 MURATA LQH32CN471K23L 15 1 Q1 TRANSISTOR, NPN SOT-23 DIODES/ZETEX FMMT493TA 16 2 Q2, Q3 TRANSISTOR, PNP SOT-23 DIODES/ZETEX MMBT3906-7-F 17 1 Q4 MOSFET, SINGLE P-CHANNEL 60V SOT-23 VISHAY SI2309CDS-T1-GE3 18 1 Q5 TRANSISTOR, NPN SOT-23 CENTRAL SEMI. CORP. CMST3904TR 19 1 R2 RES., CHIP 549Ω 0.10W 1% 0603 VISHAY CRCW0603549RFKEA 20 1 R5 RES., CHIP 499k 0.10W 1% 0603 VISHAY CRCW0603499KFKEA 21 1 R6 RES., CHIP 54.9k 0.10W 1% 0603 VISHAY CRCW060354K9FKEA 22 2 R7, R23 RES., 0.010Ω 0.125W 1% 0805 VISHAY WSL0805R0100FEA 23 1 R8 RES., CHIP 3.92k 0.10W 1% 0603 VISHAY CRCW06033K92FKEA 24 2 R9, R26 RES., CHIP 10k 0.25W 5% 1206 VISHAY CRCW120610K0JNED 25 1 R12 RES., CHIP 100Ω 0.10W 1% 0603 VISHAY CRCW0603100RFKEA 26 2 R14, R18 RES., CHIP 4.99k 0.10W 1% 0603 VISHAY CRCW06034K99FKEA 27 3 R15, R29, R37 RES., CHIP 1.00k 0.10W 1% 0603 VISHAY CRCW06031K00FKEA 28 2 R17, R30 RES., CHIP 10.0k 0.10W 1% 0603 VISHAY CRCW060310K0FKEA 29 1 R20 RES., CHIP 60.4k 0.10W 1% 0603 VISHAY CRCW060360K4FKEA 30 2 R21, R38 RES., CHIP 100k 0.10W 1% 0603 VISHAY CRCW0603100KFKEA 31 1 R22 RES., CHIP 200Ω 0.125W 1% 0805 VISHAY CRCW0805200RFKEA 32 1 R24 RES., CHIP 47.5k 0.10W 1% 0603 VISHAY CRCW060347K5FKEA 33 1 R27 RES., CHIP 73.2k 0.10W 1% 0603 VISHAY CRCW060373K2FKEA 34 1 R28 RES., CHIP 11.3k 0.10W 1% 0603 VISHAY CRCW060311K3FKEA 35 1 R31 POT. 1 TURN 10k ±10% BOURNS 91A1A-B28-A15L 36 1 R32 POT. 1 TURN 5k ±10% BOURNS 91A1A-B28-A13L 37 1 R41 RES., CHIP 1k 0.10W 5% 0603 VISHAY CRCW06031K00JNEA 38 1 R42 RES., CHIP 1.47M 0.10W 1% 0603 VISHAY CRCW06031M47FKEA 39 1 R43 RES., CHIP 10k 0.10W 5% 0603 VISHAY CRCW060310K0JNEA 40 1 R44 RES., CHIP 280k 0.10W 1% 0603 VISHAY CRCW0603280KFKEA dc2132af 7 DEMO MANUAL DC2132A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 41 1 R45 RES., CHIP 806k 0.10W 1% 0603 VISHAY CRCW0603806KFKEA 42 1 R47 RES., CHIP 5.1k 0.10W 5% 0603 VISHAY CRCW06035K10JNEA 43 1 R48 RES., CHIP 2.7k 0.10W 5% 0603 VISHAY CRCW06032K70JNEA 44 2 U1, U2 I.C., LINEAR REGULATOR DD-R (07) (1462-REV F) LINEAR TECH. CORP. LT3081ER#PBF 45 1 U3 I.C., REGULATOR QFN (28) (UDE) 3mm × 6mm LINEAR TECH. CORP. LT8612EUDE#PBF 46 1 U4 I.C., DC/DC CONVERTER DFN (08) (DD) 3mm × 3mm LINEAR TECH. CORP. LT3092EDD#PBF 47 1 U5 I.C., STEP-DOWN CONVERTER DFN (08) (DD) 3mm × 3mm LINEAR TECH. CORP. LTC3632EDD#PBF SUN ELECT. IND. 63CE22BS Optional Circuit Components 1 1 C8 CAP., ALUM 22µF 63V 25% 2 0 C16, C30 OPTIONAL 0603 3 0 C24 OPTIONAL 1210 4 1 D4 LED, GRN 5 0 R6, R19, R25, R46 OPTIONAL 0603 6 1 R13 RES., CHIP 549Ω 0.10W 1% 0603 VISHAY CRCW0603549RFKEA 7 1 R16 RES./JUMPER, CHIP 0Ω 0.25W 0603 VISHAY CRCW06030000Z0EA 8 0 R33 OPTIONAL POT. 10 TURNS 10k BOURNS 3950S-1-103L 9 0 R34 OPTIONAL POT. 10 TURNS 5k BOURNS 3950S-1-502L 1 6 E1, E2, E3, E4, E5, E6 TURRET, TESTPOINT MILL-MAX 2501-2-00-80-00-00-07-0 2 2 E7, E8 TURRET, TESTPOINT MILL-MAX 2308-2-00-80-00-00-07-0 3 1 JP1 HEADERS, DBL. ROW 2 × 3 2mm CTRS. SAMTEC TMM-103-02-L-D 4 4 J1, J2, J3, J4 CONNECTOR, BANANA JACK KEYSTONE 575-4 5 1 S1 SWITCH TOGGLE, SPDT PHILMORE, 30-10002B 6 1 XJP1 SHUNT, 2mm CTRS. SAMTEC 2SN-BK-G OSRAM OPTO SEMI. LG L29K-G2J1-24-Z Hardware 8 dc2132af + Q4 Si2309CDS GND 63V C8 22µF VIN 10V to 40V D S 0805 50V C21 1µF G 2 R6 54.9k D4 5 6 8 7 NC NC NC 4 OUT IN OUT OUT IN SET 21 1 4 5 6 7 INTVCC SYNC EN/UV VIN VIN VIN LT8612EUDE U3 9 3 2 1 R20 60.4k 700kHz LT3092EDD R48 2.7k U4 R13 Q5 549 CMST3904 C14 1µF INTVCC 30‐10002B Philmore R5 499k 1 3 R47 5.1k GREEN 50V 1210 C3 10uF VIN ON OFF RT 3 S1 TR/SS 2 20 BST NC NC NC NC FB PG BIAS SW SW SW SW SW R24 47.5k 0805 1% 200 R22 C15 0.1µF NOTE 1 6 JP1 4 5 2 VOUT MAX C30 (Opt) 5V 15V 24V U5 ISET 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. CW muRata 3 R31 10k CCW 3 7 6 3 7 6 1 1% R44 280k R42 1.47M 2 SET ILIM IMON NC IN 2 SET D5 B140 1% 5 1 R17 10.0k TEMP 1% 5 1 R30 10.0k TEMP ILIM 4 OUT 8 TAB U2 LT3081ER C23 0.01µF IMON NC IN 4 OUT 8 TAB U1 LT3081ER R45 806k VOUT ADJUST C17 2 0.01µF 1% R29 1.00k IMON 50V 1210 10uF C9 R15 1.00k 1% 8 3 6 Bourns Inc. 91A1A‐B28‐A15L GND IMON 1% 1% R38 100k Q2 R21 MMBT3906 100k 1% R37 1.00k EMZA350ADA101MF80G IMON 50V 1210 C7 10uF 9 GND GND HYST SS VFB RUN VIN L2 470µH 1 LQH32CN471K23L SW LTC3632EDD C5,C6,C19 4 7 5 2 C29 + 3x 10µF 50V 100µF 1210 35V R43 10k C25 1µF R27 R28 73.2k 11.3k R18 4.99k 1nF 1.00k R46 (Opt) C13 R16 R14 5.1k Wurth 5.5µH 744325550 L1 R41 1k Q3 MMBT3906 3 1 28 27 26 25 24 23 22 15 16 17 18 19 C4 0.1µF INTVCC PGND PGND PGND GND GND GND GND GND 8 9 10 29 14 13 12 11 VIN 549 R8 3.92K CCW 50V 1210 1206 R26 10k 3x 10µF TEMP2 50V 1210 FMMT493 Q1 C10,C11,C27 C20,C22,C28 3x 10uF TEMP1 1% R12 100 ILIM- 2 R32 5k 3 CW 1 ILIM- 1% 0805 0.010 R23 1206 R9 10k 0805 1% R7 0.010 Bourns Inc. 91A1A‐B28‐A13L R2 ILIM+ 6.3V C26 10µF ILIM+ ILIM ADJUST 50V C12 1uF GND NOTE 1 VOUT 0V ‐ 24V 0A ‐ 3A DEMO MANUAL DC2132A Schematic Diagram dc2132af 9 DEMO MANUAL DC2132A 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 10 Linear Technology Corporation dc2132af LT 0514 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2014