DEMO MANUAL DC1729A LT3086 40V, 2.1A Low Dropout Adjustable Linear Regulator with Monitoring and Cable Drop Compensation DESCRIPTION Demonstration circuit 1729A is a 2.1A low dropout adjustable linear regulator featuring the LT®3086. The device is designed with multiple features and operates over a wide 1.4V to 40V input supply range. The LT3086 requires only one resistor to set the output voltage from 0.4V to 32V and it is stable with ceramic output capacitors requiring a minimum of 10μF. The key features of the LT3086 include programmable cable drop compensation, master/slave configuration for paralleling of multiple devices for higher load current and heat spreading, output current and temperature monitoring, and programmable power good flag. PERFORMANCE SUMMARY The LT3086 is offered in the packages of 16-lead DFN, 16-lead TSSOP, 7-lead DD-PAK, and a 7-lead TO-220. The LT3086 data sheet gives a complete description of the device, operation and application information. The data sheet should be read in conjunction with this quick start guide for working on or modifying the demo circuit 1729A. Design files for this circuit board are available at http://www.linear.com/demo 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. Specifications are at TA = 25°C SYMBOL PARAMETER CONDITIONS VIN Input Supply Range VOUT = 1V, IOUT1 = 1mA 1.55 VOUT Output Voltage Shunt at 1, 2 for JP1 IOUT Maximum Output Current MIN TYP MAX UNITS 40 V 0.97 1 1.03 V Shunt at 3, 4 for JP1 1.164 1.2 1.236 V Shunt at 5, 6 for JP1 1.455 1.5 1.545 V Shunt at 7, 8 for JP1 3.201 3.3 3.399 V Shunt at 9, 10 for JP1 4.85 5 5.15 V Shunt at 11, 12 for JP1 and R10 Stuffed as 232k 11.64 12 12.36 V (Note 1) 2.1 A Note 1: The maximum output current 2.1A is when the internal current limit is active and when VIN-VOUT is smaller than 9V. For the maximum output current under other conditions, please refer to the data sheet. dc1729af 1 DEMO MANUAL DC1729A QUICK START PROCEDURE Demonstration circuit 1729A is easy to set up to evaluate the performance of the LT3086. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: Note: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the terminals of the input or output capacitors. See Figure 2 for proper scope probe technique. 3.Turn on the power at the VIN. Note: Make sure that the VIN voltage does not exceed 40V. 4.Check for the proper output voltages: Note: If there is no output, temporarily disconnect the load to make sure that the load is not set too high or is shorted. 1.Use JP1 to set the desired output voltage. 5.Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, efficiency and other parameters. 2.With power off, connect the input power supply to VIN and GND. Note: Make sure that the power dissipation is limited below the thermal limit. Figure 1. DC1729A Proper Equipment Setup VIN OR VOUT GND Figure 2. Measuring Input or Output Ripple dc1729af 2 DEMO MANUAL DC1729A THERMAL IMAGE An example thermal image shows the temperature distribution on the board. The test is done in still air at room temperature with 2.2W power dissipation in the LT3086. This gives the IC case-to-ambient thermal resistance θJA = 23°C/W on the demo board. Figure 3. Temperature Rise at 2.2W Dissipation CABLE DROP COMPENSATION The power good setting jumper JP2 on the DC1729A is used for setting the power good threshold for the corresponding output voltages. JP2 needs to be configured at the same position as JP1 for any specific output volt- ages. For example, when JP1 is configured on 7 and 8 for 3.3VOUT, JP2 also needs to be configured on 7 and 8 for the correct power good setting for 3.3VOUT. POWER GOOD SETTING The cable drop compensation on the DC1729A can be turned on by placing R4 (RCDC) with a value which is governed by the following equation provided in the data sheet: RCDC = RMON •RSET 3000 •R WIRE Please note that when cable drop compensation is activated, it also changes the power good threshold. R23 needs to be the same value as R4 in order to keep the same output voltage power good threshold at the load. dc1729af 3 DEMO MANUAL DC1729A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 CAP., X7R, 10µF 50V, 10%, 1210 MURATA, GRM32ER71H106KA12L 2 1 C2 CAP., X5R, 22µF 16V, 10%, 1206 AVX, 1206YD226KAT2A 3 1 C3 CAP., X7R, 10nF 25V, 10%, 0603 AVX, 06033C103KAT2A 4 2 R1, R12 RES., CHIP, 100k, 1/16W, 1% 0603 VISHAY, CRCW0603100KFKEA 5 1 R3 RES., CHIP, 357Ω, 1/16W, 1% 0603 VISHAY, CRCW0603357RFKEA 6 1 R5 RES., CHIP, 12.1k, 1/16W, 1% 0603 VISHAY, CRCW060312K1FKEA 7 1 R6 RES., CHIP, 16.2k, 1/16W, 1% 0603 VISHAY, CRCW060316K2FKEA 8 1 R7 RES., CHIP, 22.1k, 1/16W, 1% 0603 VISHAY, CRCW060322K1FKEA 9 1 R8 RES., CHIP, 57.6k, 1/16W, 1% 0603 VISHAY, CRCW060357K6FKEA 10 1 R9 RES., CHIP, 90.9k, 1/16W, 1% 0603 VISHAY, CRCW060390K9FKEA 11 1 R14 RES., CHIP, 82.5k, 1/16W, 1% 0603 VISHAY, CRCW060382K5FKEA 12 1 R15 RES., CHIP, 51.1k, 1/16W, 1% 0603 VISHAY, CRCW060351K1FKEA 13 1 R16 RES., CHIP, 19.1k, 1/16W, 1% 0603 VISHAY, CRCW060319K1FKEA 14 1 R17 RES., CHIP, 13.7k, 1/16W, 1% 0603 VISHAY, CRCW060313K7FKEA 15 1 R18 RES., CHIP, 10k, 1/16W, 1% 0603 NIC, NRC06F1002TRF 16 1 R20 RES., CHIP, 1.1k, 1/16W, 1% 0603 VISHAY, CRCW06031K10FKEA 17 1 U1 I.C., LT3086EFE, TSSOP16EFE-BB LINEAR TECH., LT3086EFE Additional Demo Board Circuit Components 1 0 C4 CAP., OPT 0603 2 1 C5 CAP., SMT, 10µF 50V, 50CE10BSS SANYO, 50CE10BSS 3 0 R2, R4, R10, R11, R13, R19, R21, R23 RES., CHIP, OPT 0603 OPT 4 0 R22 RES., CHIP, OPT 0805 OPT Hardware-For Demo Board Only 1 9 E1, E2, E3, E4, E5, E6, E7, E8, E9 TP, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0 2 2 JP1, JP2 JMP, 2X6, 0.079" SULLINS, NRPN062PAEN-RC 3 1 JP3 JMP, 1X2, 0.079" SULLINS, NRPN021PAEN-RC 4 2 XJP1, XJP2 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G dc1729af 4 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 D 5 4 3 1 2 1 TECHNOLOGY 2 3 + 4 5 A B C D DEMO MANUAL DC1729A SCHEMATIC DIAGRAM dc1729af 5 DEMO MANUAL DC1729A 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 dc1729af 6 Linear Technology Corporation LT 1113 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013