DEMO MANUAL DC1893A LT3697 USB 5V, 2.5A Output, 35V Input with Cable Drop Compensation DESCRIPTION Demonstration circuit 1893A is a USB 5V, 2.5A output, 35V input buck with cable drop compensation featuring the LT®3697. The LT3697 is a step-down switching regulator designed to power 5V USB applications. up a load. VSYS can also be used to supply a 100mA load. When probing the board, pay attention to GND and C_GND. On the demonstration board, they are connected together by default through R13 so a user can connect the ground clip of a probe to C_GND. However, if a user wants to evaluate an actual cable, the cable will replace R4 and R13. The copper between pads of R13 should be cut open. In this case, C_GND is no longer the same as GND. A differential measurement is needed to probe across the point of load. A precise output voltage and programmable cable drop compensation maintain accurate 5V regulation at the USB socket at the end of a long cable. The circuit was designed to run at 500kHz to avoid the AM band. The demo board has an EMI filter installed. The radiated EMI performance of the board is on Figures 3 to 5, showing the circuit passes CISPR25 Class 5 with a wide margin. The demonstration board also includes a USB socket. With the proper configuration of jumpers X1, X2, X3 and X4, the USB can be configured for different applications. See Table 1 for configurations. A 500mA onboard step load can also be activated to evaluate the load transient response of the circuit. To activate the step load, simply set jumper X5 to V+. The LT3697 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 1893A. This USB converter was optimized for a maximum VCABLE of 5V at 2.4A, enough for all USB applications. If higher, or lower load current is needed, please read the Cable Drop Compensation paragraph in the Applications section of the data sheet, and adjust all pertinent component values as needed. Always ensure the converter stays within the guaranteed switch current and the output voltage never exceeds 6.1V. If higher VCABLE voltage is needed, please refer to Applications example on the data sheet. If VCABLE is not connected to any load, VOUT can be used to power Design files for this circuit board are available at http://www.linear.com/demo/DC1893A L, LT, LTC, LTM, Linear Technology and tthe 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 SYMBOL PARAMETER CONDITIONS VIN Input Supply Range VCABLE Output Voltage Max IOUT Maximum Output Current MIN MAX 35 V 5 5.2 V 8 4.8 UNITS 2.4 IOUT = 2.4A, Measured at VOUT Efficiency TYP Switching Frequency A 90 % 500 kHz Table 1. Configure X1–X4 for Different USB Applications X1 X2 X3 X4 J3 DO NOT CARE DO NOT CARE DO NOT CARE OPEN NOT IN USE OPEN OPEN SHORT SET USB–DCP D+ D− OPEN SET USB APPLE 2.4A dc1893af 1 DEMO MANUAL DC1893A QUICK START PROCEDURE Demonstration circuit 1893A is easy to set up to evaluate the performance of the LT3697. Refer to Figure 1 for proper equipment setup and follow the procedure below: 1. With power off, connect the input power supply to VIN and GND. 2. With power off, connect the load to VCABLE and C_GND. 3. Set X1–X5 to OPEN positions. 4. Turn on the power at the input. 5. Carefully evaluate other design parameters as needed. 6. If a USB device is to be connected to J3, use Table 1 as a guide to set X1–X4 for different USB applications. The total current provided at J3 and VCABLE should not exceed 2.4A. 7. Set X5 to V+ if a quick transient test is desired. The load step applied to VCABLE is 500mA. Again, make sure the total load current does not exceed 2.4A during the test. Figure 1. Proper Equipment Setup GND VIN Figure 2. Measuring Output Ripple dc1893af 2 DEMO MANUAL DC1893A QUICK START PROCEDURE Figure 3. CISPR25, Class 5, Radiated Disturbances ALSE. Vertical Polarization Figure 4. CISPR25, Class 5, Radiated Disturbances ALSE. Horizontal Polarization dc1893af 3 DEMO MANUAL DC1893A QUICK START PROCEDURE Figure 5. CISPR25, Class 5, Radiated Disturbances ALSE. Vertical Polarization dc1893af 4 DEMO MANUAL DC1893A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART # Required Circuit Components 1 1 C1 CAP., ALUM, 22µF, 63V, 25% SUN ELECT. 63CE22BS 2 3 C2, C7, C8 CAP., X7R, 4.7µF, 50V, 10% 1206 MURATA, GRM31CR71H475KA12L 3 1 C3 CAP., X7R, 1uF, 50V, 10% 0805 AVX, 08055C105KAT2A 4 1 C4 CAP., X7R, 47µF, 10V, 10% 1210 MURATA, GRM32ER71A476KE15L 5 1 C13 CAP., X7R, 10nF, 25V, 10% 0402 MURATA, GRM155R71E103KA01D 6 3 C15 to C17 CAP., X7R, 0.1µF, 50V, 10% 0402 TDK, C1005X7R1H104K 7 1 C18 CAP., C0G, 330pF, 50V, 10% 0603 MURATA, GRM1885C1H331JA01D 8 1 C19 CAP., C0G, 1nF, 50V, 5% 0603 AVX, 06035A102JAT2A 9 1 C26 CAP., ALUM, 120µF, 16V, 20% SUN ELECT. 16HVP120M 10 1 D1 DIODE, CMDSH-3, SOD-323 CENTRAL SEMI., CMDSH-3TR 11 1 D2 RECTIFIER, 3A, 40V, SMA ON SEMI., MBRA340T3G 12 1 FB1 FERRITE BEAD, BEAD 0805 TDK MPZ2012S221AT 13 5 X1–X5 HEADERS, SGL. ROW 3 PINS 2mm CTRS. SULLINS NRPN031PAEN-RC 14 5 xX1–xX5 SHUNT, 2mm CTRS. SAMTEC 2SN-BK-G 15 1 J3 USB, RIGHT ANGLE, RECEPTACLE CNC TECH, LLC, 1002-001-01000 16 1 L1 IND., 10µH, NRS8040 TYPE TAIYO YUDEN, NRS8040T100MJGJV 17 1 L2 IND., 22µH TAIYO YUDEN, NRS8040T220MJGJV 18 1 Q1 POWER MOSFET, SOT23 DIODES INC, ZXMN3A14FTA 19 1 R1 RES., CHIP, 100k, 1/10Ω, 5% 0603 VISHAY CRCW0603100K0JNEA 20 3 R2, R6, R22 RES., CHIP, 100k, 0.06Ω, 5% 0402 VISHAY CRCW0402100KJNED 21 1 R3 RES., 0.022, 0.25Ω, 1% 1206 VISHAY WSL1206R0220FEA 22 1 R4 RES., SENSE, 0.3, 2Ω, 1% 0830 SSM THIN FILM TECH. RL7520WT-R30-F 23 2 R5, R23 RES., POWER, 18, 1Ω, 1% 2512 SSM THIN FILM TECH. CPA2512Q18R0FS-T10 24 1 R7 RES., CHIP, 14.7k, 0.1Ω, 1% 0603 VISHAY CRCW060314K7FKEA 25 1 R9 RES., CHIP, 10k, 0.06Ω, 5% 0402 VISHAY CRCW040210K0JNED 26 1 R10 RES., CHIP, 174k, 0.1Ω, 1% 0603 VISHAY CRCW0603174KFKEA 27 1 R12 RES., CHIP, 7.5k, 0.1Ω, 5% 0603 VISHAY CRCW06037K50JNEA 28 2 R15, R16 RES., CHIP, 43.2k, 0.1Ω, 1% 0603 VISHAY CRCW060343K2FKEA 29 2 R17, R18 RES., CHIP, 49.9k, 0.1Ω, 1% 0603 VISHAY CRCW060349K9FKEA 30 1 R19 RES., CHIP, 10k, 0.1Ω, 5% 0603 VISHAY CRCW060310K0JNEA 31 1 R20 RES., CHIP, 2M, 0.1Ω, 1% 0603 VISHAY CRCW06032M00FKEA 32 2 R21, R24 RES., CHIP, 2, 0.25Ω, 5% 1206 VISHAY CRCW12062R00JNEA 33 1 U1 IC., LT3697EMSE, MSE-16 LINEAR TECH., LT3697EMSE#PBF 34 1 U2 I.C., OSCILLATOR, TSOT-23-S5 LINEAR TECH., LTC6900CS5#PBF 35 1 DEMO CIRCUIT 1893A, REV 3 dc1893af 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 DC1893A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART # Additional Demo Board Circuit Components 1 0 C9 (OPT) CAP., 1206 2 1 C10 CAP., X7R, 0.1µF, 25V, 10% 0603 TDK, C1608X7R1E104K 3 2 C11, C12 CAP., X7R, 1µF, 25V, 10% 0805 TDK, C2012X7R1E105K 4 1 C14 CAP., X7R, 2.2nF, 10V, 10% 0603 AVX, 0603ZC222KAT2A 5 0 C25 (OPT) CAP., 1210 6 0 R13 RES., CHIP, 1206 7 0 R8, R14 (OPT) RES., 0402 8 0 R25 (OPT) RES., 0603 Hardware: For Demo Board Only 1 13 E1-E13 TURRET, TESTPOINT MILL-MAX, 2501-2-00-80-00-00-07-0 2 4 E14-E17 TESTPOINT, TURRET, 0.061" PBF MILL-MAX, 2308-2-00-80-00-00-07-0 3 4 MH1-MH4 STAND-OFF, NYLON, 0.375" KEYSTONE, 8832 (SNAP ON) dc1893af 6 A B C D GND VIN 8V - 35V E2 E1 E8 E6 E4 E11 C16 0.1µF 50V 100k R6 C8 4.7µF 50V 1206 R7 14.7k 0603 R22 100k C7 4.7uF 50V 1206 FB1 + C18 330pF 0603 R12 7.5k 0603 C19 1nF 0603 C1 22µF 63V SUNCON 63CE22BS 5 1. ALL RESISTORS ARE 0402. ALL CAPACITORS ARE 0402. NOTES: UNLESS OTHERWISE SPECIFIED RCBL GND SYNC EN C15 0.1µF 50V VIN L2 22µH NR8040T220M 4 R25 OPT 0603 C2 4.7µF 50V 1206 R20 2M 0603 OPT R8 C17 0.1µF 50V FLT 3 SET R10 174k 0603 R2 100K 6 8 7 9 5 3 2 1 2 4 RT OUT 10k 0603 5 R19 C14 2.2nF 0603 U2 LTC6900CS5 V+ 3 1 USB5V SYS ISN ISP SW SW BST U1 LT3697EMSE OPEN X5 RLIM VC RCBL SYNC EN VIN VIN VSYS E10 VSYS R1 100k 0603 GND 17 FLT 3 C3 1µF 16V L1 0805 10uH R14 OPT R21 2 1206 R24 2 1206 Q1 ZXMN3A14F R5 R23 18 18 2512 2512 R18 49.9k 0603 R16 43.2k 0603 R17 49.9k 0603 R15 43.2k 0603 10k OPEN DX2 3 2 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. OPEN 2 X3 DATE: N/A SIZE GND VOUT 5.xV / 2.4A C_GND VCABLE 5V / 2.4A 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com USB 1 2 1 3 2 4 3 4 J3 E9 E7 E5 C11 E3 1µF 25V 0805 VCABLE C12 1µF 25V 0805 E15 VCABLE 1 LT3697EMSE DEMO CIRCUIT 1893A SHEET 1 OF USB 35V, 2.5A BUCK WITH CABLE DROP COMPENSATION 1 3 REV. LTC Confidential-For Customer Use Only TECHNOLOGY Fax: (408)434-0507 DATA- DATA+ 1 VSYS C10 5.xV / 0.1A 0.1µF E13 25V 0603 GND E12 0.3 2W 0830 C-GND R13 OPT 1206 E17 R4 Monday, September 08, 2014 IC NO. TITLE: SCHEMATIC 1 SHORT GND E14 VCABLE SUNCON 16HVP120M 120uF 16V + C26 X4 OPEN SET 3 1 0.022 1206 E16 VOUT X1 OPEN D+ 3 1 10nF R9 C13 C9 OPT 10V 1206 CUSTOMER NOTICE C25 OPT 1210 R3 VSYS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. NRS8040T100MJGJV C4 47µF 10V D2 MBRA340T3G 1210 VCABLE 12 13 10 11 16 15 14 D1 CMDSH-3 2 2 4 1 V+ GND 2 3 2 3 1 DIV 4 2 2 3 1 5 A B C D DEMO MANUAL DC1893A SCHEMATIC DIAGRAM dc1893af 7 DEMO MANUAL DC1893A 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 dc1893af 8 Linear Technology Corporation LT 1014 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2014