DEMO MANUAL DC2318A LT3089EDF 800mA Rugged Linear Regulator with Monitors DESCRIPTION Demonstration circuit 2276A is an 800mA low dropout rugged linear regulator featuring LT®3089. Key features of the IC are the extended safe operating area (SOA), output current monitor, temperature monitor and programmable current limit. The LT3089 can be paralleled for higher output current or heat spreading. The device withstands reverse input and reverse output-to-input voltages without reverse current flow. The LT3089’s precision 50µA reference current source allows a single resistor to program output voltage to any level between zero and 34.5V. The current reference architecture enables load regulation to be independent of output voltage. The LT3089 is stable with or without input and output capacitors. The output current monitor (IOUT/5000) and die junction temperature output (1µA/°C) provide system monitoring and debug capability. In addition, a single resistor programs current limit. Internal protection circuitry includes reverse-battery and reverse-current protection, current limiting and thermal limiting. DC2318A uses the LT3089EDF which is a 12-lead (4mm × 4mm) plastic DF package with an exposed pad on the bottom-side of the IC for better thermal performance. These features make DC2318A an ideal circuit for surfacemount power supply, rugged industrial power supply, low output voltage supply and post regulator for switching supplies. Design files for this circuit board are available at http://www.linear.com/demo/DC2318A 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. PERFORMANCE SUMMARY Specifications are at TA = 25°C VIN(V) CONDITIONS IOUT MIN Shunt at 1.2V for JP1 10mA 2.5 800mA 10mA Shunt at 1.5V for JP1 Shunt at 1.8V for JP1 Shunt at 2.5V for JP1 Shunt at 3.3V for JP1 Shunt at 5.0V for JP1 TYP VOUT(V) MAX* MIN TYP MAX 36.0 1.15 1.2 1.25 2.9 3.7 1.15 1.2 1.25 2.8 36.0 1.44 1.5 1.56 800mA 3.2 4.0 1.44 1.5 1.56 10mA 3.1 36.0 1.74 1.8 1.87 800mA 3.5 4.3 1.74 1.8 1.87 10mA 3.8 36.0 2.42 2.5 2.59 800mA 4.2 5.0 2.42 2.5 2.59 10mA 4.6 36.0 3.19 3.3 3.42 800mA 5.0 5.8 3.19 3.3 3.42 10mA 6.3 36.0 4.83 5.0 5.18 800mA 6.7 7.5 4.83 5.0 5.18 *The maximum input voltage for 800mA load current is set by the 50°C temperature rise of LT3089 on the demo circuit. Higher input voltage can be reached if larger copper area or force-air cooling is applied. The output current is also limited by the differential voltage of input and output voltage, please refer the data sheet for details. dc2318af 1 DEMO MANUAL DC2318A QUICK START PROCEDURE Demonstration circuit 2318A is easy to set up to evaluate the performance of the LT3089. 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 1. Use JP1 to set the desired output voltage 3. Turn on the power at the VIN. NOTE: Make sure that the VIN voltage does not exceed 36V. 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. 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. NOTE: Make sure that the power dissipation is limited below the thermal limit. 2. With power off, connect the input power supply to VIN and GND. + POWER SUPPLY IIN – – – + + – – VIN + VOUT LOAD + DC2318A F01 Figure 1. Test Procedure Setup Drawing for DC2276A VOUT GND Figure 2. Measuring Input or Output Ripple 2 dc2318af DEMO MANUAL DC2318A THERMAL IMAGE An example thermal image shows the temperature distribution on the PC board. The test is done in still air at room temperature with 2W power dissipation in the LT3089 IC. This gives an IC case-to-ambient thermal resistance of θCA = 23.5°C/W on the demo circuit. This IC, at its highest point reaches 75°C, at VIN = 5.0V, VOUT = 2.5V, and 800mA load current. Figure 3. Temperature Rise at 2W Dissipation (VIN = 5.0V, VO =2.5V, IO = 800mA) dc2318af 3 DEMO MANUAL DC2318A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 CAP, X7R, 1µF, 50V, 10%, 0805 MURATA, GRM21BR71H105KA12L 2 1 C2 CAP., CER., 10µF, X5R, 50V, 20%, 1206 MURATA, GRM31CR61H106MA12L 3 1 C3 CAP., CER., 0.01µF, X7R, 25V, 10%, 0603 MURATA, GRM188R71E103KA01D 4 1 C4 CAP., ALUM., 10µF, 50V, 20%, SMD SUN ELECT., 50CE10BSS 5 1 R1 RES., 301k, 1/10W, 1%, 0603 VISHAY, CRCW0603301KFKEA 6 1 R2 RES., 390Ω, 1/8W, 1%, 0805 VISHAY, CRCW0805390RFKEA 7 1 R3 RES., 5.1k, 1/10W, 1%, 0603 VISHAY, CRCW06035K10FKEA 8 2 R4, R5 RES., 1k, 1/10W, 1%, 0603 VISHAY, CRCW06031K00FKEA 9 1 R6 RES., 26.1k, 1/10W, 1%, 0603 VISHAY, CRCW060326K1FKEA 10 1 R7 RES., 33.2k, 1/10W, 1%, 0603 VISHAY, CRCW060333K2FKEA 11 1 R8 RES., 41.2k, 1/10W, 1%, 0603 VISHAY, CRCW060341K2FKEA 12 1 R9 RES., 60.4k, 1/10W, 1%, 0603 VISHAY, CRCW060360K4FKEA 13 1 R10 RES., 84.5k, 1/10W, 1%, 0603 VISHAY, CRCW060384K5FKEA 14 1 R11 RES., 150k, 1/10W, 1%, 0603 VISHAY, CRCW0603150KFKEA 15 1 U1 I.C., LINEAR REGULATOR, 12DFN (4 × 4) LINEAR TECH., LT3089EDF#PBF Additional Demo Board Circuit Components 16 0 C5, C6 (OPT) CAP., 0603 17 0 R12, R13 (OPT) RES., 0603 Hardware: For Demo Board Only 18 4 E1, E2, E4, E5 TEST POINT, TURRET, .094" MTG. HOLE MILL-MAX, 2501-2-00-80-00-00-07-0 19 2 E3, E6 TEST POINT, TURRET, .061" MTG. HOLE MILL-MAX, 2308-2-00-80-00-00-07-0 20 1 JP1 CONN., HEADER, 2 × 7, 2mm SAMTEC, TMM-107-02-L-D 21 1 XJP1 SHUNT, 2mm SAMTEC, 2SN-BK-G 4 dc2318af DEMO MANUAL DC2318A SCHEMATIC DIAGRAM dc2318af 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. 5 DEMO MANUAL DC2318A 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 6 dc2318af Linear Technology Corporation LT 0316 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2016