DEMO MANUAL DC2138A LT8301 42VIN Micropower Isolated Flyback Converter with 65V/1.2A Switch Description Demonstration circuit 2138A is an isolated flyback converter featuring the LT8301. This demo circuit outputs 5V from a 10V to 32V input, with a nominal of 24V. The output current capability increases with the input voltage. The standby input current of the demo circuit is less than 950µA (typical) at VIN = 24V. The Performance Summary table summarizes the performance of the demo board at room temperature. The demo circuit can be easily modified for different applications with some pre-designed transformers. The DC2138A needs a very small minimum load (~6mA) to regulate the output voltage, thanks to the accurate current limit capability and ultralow switching frequency of LT8301 at very light load. On the board, a Zener diode is placed on the output to clamp the voltage to ~5V. This Zener is optional, and can be replaced with a 0.8k resistor. The LT8301 is a simple-to-use high-voltage monolithic isolated flyback converter. No third winding or opto-isolator Performance Summary PARAMETER is required for regulation. The part sets the isolated output voltage with a single external resistor and integrates loop compensation and soft-start circuitry inside the IC. Boundary mode operation provides a small magnetic solution with improved load regulation. Low-ripple Burst Mode® operation maintains high efficiency at light loads while minimizing the output voltage ripple. A 1.2A, 65V DMOS power switch is integrated along with all high-voltage circuitry and control logic into a 5-lead ThinSOT™ package. The LT8301 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this quick start guide for demo circuit 2138A. Design files for this circuit board are available at http://www.linear.com/demo/DC2138A L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C CONDITIONS Input Voltage Standby Current MIN TYP MAX 10 24 32 IOUT = 0mA, VIN = 24V, VOUT = 5V 950 5 UNITS V µA Output Voltage VIN = 12V to 32V, IOUT = 6mA to 700mA 4.75 Maximum Output Current VIN = 12V VIN = 24V 700 1000 5.25 V Output Voltage Ripple (Peak to Peak) VIN = 24V, IOUT = 1A 90 mV Switching Frequency VIN = 24V, IOUT = 1A 190 kHz Efficiency VIN = 24V, IOUT = 1A 83.2 % mA mA dc2138af 1 DEMO MANUAL DC2138A Quick Start Procedure Demo circuit 2138A is easy to set up to evaluate the performance of the LT8301. Refer to Figure 1 for proper equipment setup and follow the procedure below. 1.With power off, connect the input power supply to the board through VIN and GND terminals. Connect the load to the terminals VOUT+ and VOUT– on the board. 2.Turn on the power at the input. Increase VIN slowly to 10V. NOTE. Make sure that the input voltage is always within spec. To operate the board with higher input/output voltage, input capacitor, output capacitor and output diode with higher voltage ratings are needed. NOTE. To run overload tests on the demo board at high line, additional RC snubber might be needed to make sure the voltage spike at the switching node is always less than 65V. 3.Check for the proper output voltages. The output should be regulated at 5V (±5%). NOTE. The LT8301 requires very small minimum load to maintain good output voltage regulation. A Zener diode is placed on the output to clamp the voltage to ~5V. This Zener is optional, and can be replaced with a 0.8k resistor. 4.Once the proper output voltage is established, adjust the input voltage and load current within the operating range and observe the output voltage regulation, transient, ripple voltage, efficiency and other parameters. NOTE. When measuring the input or output voltage ripples, 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 VIN or VOUT capacitor terminals. See Figure 2 for proper scope probe technique. Figure 1. Proper Measurement Equipment Setup dc2138af 2 DEMO MANUAL DC2138A Quick Start Procedure INPUT OR OUTPUT CAPACITOR Figure 2. Proper Scope Probe Placement for Measuring Input or Output Ripple 90 EFFICIENCY (V) 85 80 75 70 VIN = 12V VIN = 24V VIN = 32V 65 60 0 0.2 0.6 0.4 LOAD CURRENT (A) 0.8 1.0 dc2138a F03 Figure 3. Typical Efficiency Curves 5.25 5.20 5.15 VOUT (V) 5.10 5.05 5.00 4.95 4.90 4.85 VIN = 12V VIN = 24V VIN = 32V 4.80 4.75 0.006 0.206 0.606 0.406 0.806 LOAD CURRENT (A) dc2138a F04 Figure 4. Typical Regulation Curves dc2138af 3 DEMO MANUAL DC2138A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., ALUM., 22µF, 50V SUN ELECT., 50CE22BS Required Circuit Components 1 1 Cin 2 1 C1 CAP., X7R, 10µF, 50V, 10%, 1210 MURATA, GRM32ER71H106KA12L 3 1 C2 CAP., X5R, 100µF, 6.3V, 20%, 1210 MURATA, GRM32ER6J107ME20L 4 1 D1 DIODE, PMEG3020EH, SOD-123 NXP, PMEG3020EH 5 1 D2 DIODE, 5.6V, SOD-523 DIODES., BZT52C5V6T-7-F 6 1 D3 DIODE., 1N4148WS, SOD323 DIODES., 1N4148WS-7-F 7 1 D4 DIODE, CMHZ5248B, SOD-123 CENTRAL., CMHZ5248B 8 1 R1 RES., CHIP, 1M, 1/8W, 1% 0805 VISHAY, CRCW08051M00FKEA 9 1 R2 RES., CHIP, 210k, 1/10W, 1% 0603 VISHAY, CRCW0603210KFKEA 10 1 R3 RES., CHIP, 154k, 1/10W, 1% 0603 VISHAY, CRCW0603154KFKEA 11 1 T1 TRANSFORMER, 750313974 WURTH, 750313974 12 1 U1 I.C. FLYBACK CONVERTER, SOT23-5 LINEAR TECH., LT8301ES5#PBF CAP., X7R, 0.22µF, 6.3V, 10%, 0603 MURATA, GRM188R70J224KA Additional Demo Board Circuit Components 1 0 C3 (OPT) 2 0 C4 (OPT) CAP., X7R, 0.01µF, 50V, 10%, 0603 AVX, 06035C103KAT2A 3 0 C5 (OPT) CAP., X7R, 4.7µF, 50V, 10%, 1210 AVX, 12105C475KAT2A 4 0 C6 (OPT) CAP., ALUM., 22µF, 50V SUN ELECT., 50CE22BS 5 0 C7 CAP., X7R, 3300pf, 500V, 10% 1210 AVX, 12107C332KAT2A 6 0 FB1 (OPT) BEAD, 1206 TAIYO YUDEN, MJ3216HS800 7 0 L1 (OPT) IND., 10µH SUMIDA, CDRH4D22HPNP-100MC 8 0 R4 (OPT) RES., CHIP, 2.21k, 1/8W, 1% 0805 VISHAY, CRCW080512K21FKEA Hardware: For Demo Board Only 1 5 E1-E5 TESTPOINT, TURRET, 0.094" pbf MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 JP1 3 PIN 0.079" SINGLE ROW HEADER SAMTEC, TMM103-02-L-S 3 1 XJP1 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G dc2138af 4 E2 R2 210K R1 1M 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. 1. ALL RESISTORS AND CAPACITORS ARE 0603. NOTE: UNLESS OTHERWISE SPECIFIED E5 EN/UVLO JP1 1 EN 2 3 DIS GND 50CE22BS 22uF 50V +Cin C1 10uF 50V 1210 3 2 1 SW VIN R3 154K RFB GND EN/UV U1 LT8301ES5 4 5 SW 2 1 1 2 D3 1N4148WS CMHZ5248B D4 R4 OPT C3 OPT C7 3.3nF VIN 1210 250V 7 1 8 6 4 5 C4 0.01uF,50V 0603 C5 4.7uF,50V 1210 + SUMIDA CDRH4D22/HP L1 10UH VOUT+ C6 22uF,50V 50CE22BS VIN VOUT- [email protected], VIN>12V [email protected], VIN>24V E4 E3 D2 BZT52C5V6T-7 5.6V OPTIONAL CIRCUIT C2 100uF 6.3V 1210 D1 PMEG3020EH 1 2 TAIYO YUDEN FB MJ3216HS800 FB1 BEAD WURTH, 750313974 T1 1 2 VIN E1 10V - 32V VIN DEMO MANUAL DC2138A Schematic Diagram dc2138af 5 DEMO MANUAL DC2138A 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 dc2138af 6 Linear Technology Corporation LT 0314 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2014