DEMO MANUAL DC2067A LT8710 Synchronous Inverting DC/DC Converter DESCRIPTION Demonstration circuit 2067A is a synchronous inverting converter (CUK topology) featuring the LT®8710 switching controller. It regulates a –5V, 6A output from a 4.5V to 28V input source, and operates at 300kHz switching frequency. The LT8710 features simple negative or positive output voltage programming. The DC2067 programs a –5V output with a single resistor. At light load, the LT8710 can operate at forced continuous conduction mode (CCM) or discontinuous conduction mode (DCM), set by its MODE pin. The DC2067A selects DCM, which maintains high efficiency at light load. The DC2067A can be modified from a CUK converter to other topology. Synchronous SEPIC and synchronous BOOST schematics are provided in the data sheet. Please consult the factory or LT8710 data sheet for details regarding how to customize the DC2067A or how to design different topologies for custom specifications. There are some optional components on the DC2067A to facilitate modifications; see Full Schematic Diagram for component designation. 2. The optional RC snubber (R4, C1) across the flying capacitor could help to damp the feedback control loop for some applications using two separate inductors. 3. The optional input capacitors (CIN5, CIN6) or output capacitors (CO5, CO6) could be installed to reduce voltage ripple for some low voltage and/or high current applications. 4. The optional RC (R24, C19) snubber could be installed to damp the switch node spike and reduce the EMI noise. 5. The optional current sensing resistor filters (located near CSP and CSN pins, ISP and ISN pins) might be required in certain applications with excessive switching noise. The LT8710 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 2067A. 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. 1. The optional N-FET (MN2) or P-FET (MP2) could be added to increase power delivery and improve thermal dissipation. PERFORMANCE SUMMARY PARAMETER Specifications are at TA = 25°C CONDITIONS MIN TYP 4.5 12 28 V VIN = 4.5V to 28V, IOUT = 0A to 6A –4.85 –5 –5.15 V Input Voltage Output Voltage Maximum Output Current Output Voltage Ripple 6 VIN = 4.5V to 28V, IOUT = 6A (20MHz BW) Typical Switching Frequency Efficiency MAX UNITS A 25 mVP-P 300 kHz VIN = 5V, IOUT = 6A 85 % VIN = 12V, IOUT = 6A 88.5 % VIN = 24V, IOUT = 6A 85.5 % dc2067af 1 DEMO MANUAL DC2067A QUICK START PROCEDURE Demonstration circuit 2067A is easy to set up to evaluate the performance of the LT8710. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1.With the power off, connect the input power supply to the board through VIN and PGND terminals. Connect the load to the terminals VOUT and PGND on the board. Make sure that the input power supply has sufficient current rating at minimum input voltage for the required output load. 2.Turn on the power at the input. Note: Make sure that the input voltage does not exceed 28V. 3. Check for the proper output voltages. The output should be regulated at –5.0V (±3%). 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 and PGND, or VOUT and PGND terminals. See Figure 2 for proper scope probe technique. 5.The DC2067A is equipped with an output capacitor CO1 (270µF) that approximates typical system rail capacitance. If the system board already has capacitance of similar value, CO1 can be removed. The input capacitor CIN1 is used to help with filtering when the board is connected to lab power supply with long leads. The capacitor CIN1 can be removed if the input power source is close and has low source impedance. If there is no output, temporarily disconnect the load to make sure that the load is not set too high. 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, ripple voltage, efficiency and other parameters. dc2067af 2 DEMO MANUAL DC2067A QUICK START PROCEDURE Figure 1. Proper Measurement Equipment Setup INPUT OR OUTPUT CAPACITOR Figure 2. Proper Scope Probe Placement for Measuring Input or Output Ripple –5VOUT Efficiency vs Load Current 95 90 EFFICIENCY (%) 85 80 75 70 65 60 55 50 5VIN 12VIN 24VIN 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 LOAD CURRENT (A) Figure 3. Typical Efficiency Curve dc2067af 3 DEMO MANUAL DC2067A QUICK START PROCEDURE N-FET Temperature Rise vs Input Voltage 80 TEMPERATURE RISE (°C) 70 60 50 40 30 20 6AOUT 5AOUT 4AOUT 10 0 4.5 6 20 16 12 INPUT VOLTAGE (V) 9 24 28 Figure 4. N-FET (MN1) Temperature Rise vs Input Voltage VOUT 20mV/DIV 2µs/DIV Figure 5. Output Voltage Ripple at 12VIN and 6AOUT, 20MHz Bandwidth dc2067af 4 DEMO MANUAL DC2067A PARTS LIST ITEM QTY REFERENCE Required Circuit Components 1 6 C2, C3, C4, CIN2, CIN3, CIN4 2 1 C5 3 2 C11, C14 4 1 C13 5 1 C15 6 1 C16 7 1 C17 8 1 C18 9 1 CIN1 10 1 CO1 11 3 CO2, CO3, CO4 12 1 D1 13 1 D2 14 1 L1 15 1 MN1 16 1 MP1 17 1 R1 1 R3 18 19 8 R5, R6, R7, R9 ,R12, R15, R16, R18 20 1 R5, R6, R7, R9, R12, R15, R16, R19 21 1 R13 22 1 R17 23 2 R19, R23 24 1 R20 25 1 R21 26 1 R22 27 1 U1 28 1 Additional Demo Board Circuit Components 1 0 C1 (OPT) 2 0 C20, CIN5, CIN6, CO5, CO6 (OPT) 3 0 C6, C7, C8, C9, C10 (OPT) 4 0 C12 (OPT) 5 0 C19 (OPT) 6 0 MN2 (OPT) 7 0 MP2 (OPT) 8 0 R2 (OPT) 9 0 R4, R24 (OPT) 10 0 R10, R11, R14 (OPT) Hardware-For Demo Board Only 1 14 E1-E14 2 1 JP1 3 1 XJP1 4 4 MH1-MH4 PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., X7R, 10µF, 50V, 10% 1210 CAP., X7R, 0.47µF, 16V, 10% 0805 CAP., X7R, 2.2µF, 16V, 10%, 0805 CAP., X7R, 4.7µF, 50V, 10%, 1206 CAP., X7R, 4.7nF, 16V, 10%, 0603 CAP., C0G, 100pF, 50V, 5%, 0603 CAP., X7R, 470nF, 16V, 10%, 0603 CAP., X7R, 47nF, 16V, 10%, 0603 ALUMINUM CAP., 330µF, 35V, OS-CON, 270µF, 10V, E7 SIZE CAP., X5R, 100µF, 6.3V, 20% 1210 DIODE, PMEG4030EP, SOD128 DIODE, SCHOTTKY 30V 500MA SOD323F IND, 2.2µH N-CH FET, POWERPAK SO-8 P-CH FET, DPAK RES., SENSE, 0.002Ω, 1W, 1% RL3720W RES., SENSE, 0.006Ω, 1W, 1% RL3720W Res., Chip, 0Ω, 0.1W, 0603 Res., Chip, 499Ω, 0.1W, 1%, 0603 Res., Chip, 60.4k, 0.1W, 1%, 0603 Res., Chip, 12.7k, 0.1W, 1%, 0603 Res., Chip, 100k, 0.1W, 1%, 0603 Res., Chip, 10k, 0.1W, 1%, 0603 Res., Chip, 118k, 0.1W, 1%, 0603 Res., Chip, 12.1k, 0.1W, 1%, 0603 IC, DC/DC CONVERTER, TSSOP-20 FAB, PRINTED CIRCUIT BOARD MURATA, GRM32ER71H106KA12L MURATA, GRM21BR71C474KA01L MURATA, GRM21BR71C225KA12L TDK, C3216X7R1H475K MURATA, GRM188R71C472A01D TDK, C1608C0G1H101J MURATA, GRM188R71C474KA88D TDK, C1608X7R1C473K NIPPON, EMZA350ADA331MJA0G SANYO/PANASONIC, 10SVPC270M MURATA, GRM32ER60J107ME20L NXP, PMEG4030EP NXP, PMEG3005EJ+115 WÜRTH, 74485540220 FAIRCHILD, FDMS86500L FAIRCHILD, FDD4141 SUSUMU, RL3720WT-R002-F SUSUMU, RL3720WT-R006-F VISHAY, CRCW06030000Z0EA VISHAY, CRCW0603499RFKEA VISHAY, CRCW060360K4FKEA VISHAY, CRCW060312K7FKEA VISHAY, CRCW0603100KFKEA VISHAY, CRCW060310K0FKEA VISHAY, CRCW0603118KFKEA VISHAY, CRCW060312K1FKEA LINEAR TECH., LT8710EFE#PBF DEMO CIRCUIT 2067A REV 4 CAP., 2220 CAP., 1210 CAP., 0603 CAP., 1206 CAP., 0805 N-CH FET, POWERPAK SO-8 P-CH FET, DPAK RES., SENSE, RL3720W RES., 1210 RES., 0603 TESTPOINT, TURRET, 0.094" PBF 3-PIN 0.079 SINGLE ROW HEADER SHUNT, 0.079" CENTER STAND-OFF, NYLON 0.50" MILL-MAX, 2501-2-00-80-00-00-07-0 SULLINS, NRPN031PAEN-RC SAMTEC, 2SN-BK-G KEYSTONE, 8833(SNAP ON) dc2067af 5 SYNC AGND EN/FBIN PGND VIN 4.5V - 28V E11 E10 E9 E4 E3 E2 E1 5 SYNC CIN2 10uF 50V 1210 CIN3 10uF 50V 1210 CIN4 10uF 50V 1210 MN1 FDMS86500L R1 0.002 RL3720W CCM DCM 4 JP1 MODE 3 INTVCC 1. ALL RESISTORS ARE 0603. ALL SMD CAPACITORS ARE 0603. 4 C14 2.2uF 0805 R17 12.7K 2 BG MP1 FDD4141 4 12 16 13 14 15 INTVCC EN/FBIN VIN CSN CSP C5 0.47uF 0805 R8 499 3 D1 PMEG4030EP U1 LT8710EFE VIN 1 R20 10K 10uF 50V C4 1210 C13 4.7uF 50V 1206 50V C3 1210 1210 NOTE: UNLESS OTHERWISE SPECIFIED EN/FBIN 330uF 35V + CIN1 VIN L1B 2.2uH 74485540220 2 3 10uF 50V 10uF 3 4 VC FLAG INTVEE BIAS FBX ISN RL3720W R3 0.006 R21 C17 118k 470nF R23 100K 3 L1A 2.2uH 74485540220 1 BIAS INTVEE FLAG VC 8 9 4 2 R22 12.1K C15 4.7nF FBX 1 C18 47nF IMON A B C D 8 7 6 5 1 2 3 C2 1 BG 11 MODE 17 4 3 SS SYNC 19 1 2 10 TG 7 ISP RT 18 RT SS ISP 6 PMEG3005EJ ISN 6 D2 20 GND 21 GND 5 IMON C16 100pF C11 2.2uF 0805 R13 60.4k 2 2 R19 100K VOUT CO4 100uF 6.3V 1210 CO3 100uF 6.3V 1210 1 IMON INTVCC CO2 100uF 6.3V 1210 1 + 5 E14 E13 E12 E8 E7 E6 CO1 270uF 10V E5 FLAG IMON INTVCC PGND VOUT -5V , 6A A B C D DEMO MANUAL DC2067A SIMPLE SCHEMATIC DIAGRAM dc2067af SYNC AGND EN/FBIN PGND VIN 4.5V - 28V E11 E10 E9 E4 E3 E2 E1 5 SYNC CIN2 10uF 50V 1210 CIN3 10uF 50V 1210 CIN4 10uF 50V 1210 MN2 OPT CIN6 OPT 1210 R1 0.002 RL3720W 4 NG MN1 FDMS86500L CIN5 OPT 1210 0 R15 0 R7 CCM JP1 MODE 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 ARE 0603. ALL SMD CAPACITORS ARE 0603. 4 C14 2.2uF 0805 R17 12.7K INTVCC 3 BG MP1 FDD4141 4 4 12 16 13 14 15 PG INTVCC EN/FBIN VIN CSN CSP R23 100K 3 1 4 C17 470nF R21 118k R2 OPT VC FLAG INTVEE BIAS INTVEE FLAG VC 9 4 2 C18 47nF BIAS R22 12.1K C16 100pF 0 C11 2.2uF 0805 C8 OPT 60.4k R18 C15 4.7nF FBX 1 0 R12 R13 0.006 R11 OPT 8 ISN C6 OPT R10 OPT R3 RL3720W RL3720W FBX C7 OPT R9 0 74485540220 L1A 2.2uH D2 PMEG3005EJ C5 0.47uF 0805 R5 0 3 MP2 OPT R8 499 3 3 D1 PMEG4030EP U1 LT8710EFE VIN 2 C13 4.7uF 50V 1206 0 1 R20 10K C10 OPT NG R6 OPT C20 1210 R24 OPT 1210 DCM C9 OPT 4 10uF 50V C4 1210 C19 OPT 0805 50V NOTE: UNLESS OTHERWISE SPECIFIED EN/FBIN 330uF 35V + CIN1 VIN L1B 2.2uH 74485540220 2 3 10uF 50V 10uF OPT 2220 C1 C3 1210 1210 C2 OPT 1210 R4 IMON A B C D 8 7 6 5 1 2 3 8 7 6 5 1 2 3 PG 1 1 BG 11 MODE 17 4 3 SS SYNC 19 1 2 Q2-G 10 TG SS 7 ISP RT 18 RT 6 ISN ISP 20 GND 21 GND 5 IMON 2 C12 OPT 1206 R14 OPT 2 0 R16 R19 100K CO6 OPT 1210 CO5 OPT 1210 VOUT CO4 100uF 6.3V 1210 CO3 100uF 6.3V 1210 1 IMON INTVCC CO2 100uF 6.3V 1210 1 + 5 E14 E13 E12 E8 E7 E6 CO1 270uF 10V E5 FLAG IMON INTVCC PGND VOUT -5V , 6A A B C D DEMO MANUAL DC2067A FULL SCHEMATIC DIAGRAM (OPTIONAL COMPONENTS SHOWN) dc2067af 7 DEMO MANUAL DC2067A 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 dc2067af 8 Linear Technology Corporation LT 0114 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2014