DEMO MANUAL DC2220A LTC3643 Bidirectional Charger/Regulator for System Power Backup DESCRIPTION Demonstration circuit 2220A is a 2A, bidirectional charger/ regulator featuring the LTC®3643, a bidirectional synchronous step-up charger and step-down converter. DC2220A implements backup by charging a storage capacitor up to 40V in boost mode, when the input voltage is present. It discharges the storage capacitor in buck mode, providing a regulated load voltage of 3V to 17V (set to 5V), when the input is interrupted. Its wide voltage range, both in capacitor charger mode and in system backup mode, makes it well suited to a wide variety of applications. The ability of the LTC3643 to boost an input rail to a relatively high voltage of 40V, combined with the DC2220 option of adding external capacitor banks, makes this regulator an excellent choice for energy storage applications. The DC2220A features automatic switching from charge to backup mode, 2A input current limit during charging, the ability to set maximum current in the backup mode of operation, Burst Mode® operation, fast 1MHz switching frequency, and open-collector outputs to indicate charge status and input power fail. The 1MHz constant-frequency operation results in a small and efficient circuit. In backup mode, the LTC3643 provides high output voltage accuracy over a wide load range with no minimum load requirement. Demo circuit 2220A is set up for automatic mode operation. In this mode, the DC2220 automatically charges the energy storage capacitor when a system voltage is present. It automatically switches to work as a step-down DC/DC converter providing system backup power to the load when system power is removed. An on board MOSFET isolates the backup circuit from the input line if the system voltage is not present, implementing PowerPath™ functionality. The DC2220A supports three levels of load current limits: 2A, 3A and 4A when working as step-down converter discharging the energy storage capacitor. The DC2220A has a small circuit footprint. It is a high performance and cost effective solution for high voltage capacitor backup converters, servers, solid-state drives, RAID and RF systems. The LTC3643's input disconnect circuitry protects the DC2220A from short circuit and overcurrent conditions in the boost mode of operation, in case a short circuit occurs on a high voltage rail. A similar circuit protects the DC2220A against a short circuit in step-down mode, when the load is supplied from an energy storage capacitor. Design files for this circuit board are available at http://www.linear.com/demo/DC2220A L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY Specifications are at TA = 25°C PARAMETER CONDITIONS UNITS Minimum Input Supply Voltage 3.0 V Maximum Input Supply Voltage 17.0 V 3.0 to 17.0 V System Voltage Range Backup (Step-Down) Mode Energy Storage Capacitor Voltage Range 3.0V to 40V Typical Switching Frequency Efficiency Typical, Backup Mode VCAP = 12V, VLOAD = 5.0V, ILOAD = 0.5A V 1.0 MHz 93 % dc2220afb 1 DEMO MANUAL DC2220A QUICK START PROCEDURE Demonstration circuit 2220A is easy to set up to evaluate the performance of the LTC3643 bidirectional regulator. Refer to Figure 1 for the 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 VIN or VOUT and GND terminals. See Figure 2 for proper scope probe technique. To verify the capability of the DC2220A for charging energy storage capacitors, proceed with the following steps: 1. Place jumper RUN (JP1) to OFF position. 2. Place jumper ILIM_BUCK (JP2) to 2.0A position. 3. With power off, connect the input power supply to terminals VIN (E1) and GND, voltmeter to VCAP (E8) and GND, load to LOAD (E3) and GND as shown on Figure 1. – 20V POWER SUPPLY + – + + – LOAD Figure 1. Proper Measurement Equipment Setup GND VIN Figure 2. Measuring Input or Output Ripple 2 dc2220afb DEMO MANUAL DC2220A QUICK START PROCEDURE 4. Turn the input power source on and slowly increase the input voltage to 5.5V. Set the load to 0.1A. You have to see voltage around 4.8V on terminal LOAD, a diode forward voltage drop lower compared to VIN. If there is no output, temporarily disconnect the load to make sure that the load is not set too high. 5. Place jumper RUN (JP1) in the ON position. Voltage on VCAP terminal should rise to 39V level. Voltage on terminal LOAD should be equal to input voltage. To verify the ability of DC2220 to work in backup mode, proceed with the following: 6. Disconnect input power from VIN terminal; energy storage capacitor C5 starts discharging from 39V level, however LTC3643 will maintain a voltage of 5.0V on terminal LOAD. 7. To increase holdup time, install optional capacitor C6 on the bottom side of DC2220A or connect additional capacitor bank to terminals VCAP (E8) and GND (E7). 8. Repeat steps 1 to 7 for different load currents and VIN voltages. 9. You can measure voltage regulation and ripple in backup mode on VLOAD terminals. 10.Make sure that input voltage on VIN terminals does not exceed 17V and VCAP voltage is not set above 40V. Figure 3 illustrates power interruption. In the beginning of the process VIN (yellow) is 5.5V and supplies LOAD rail, PFI signal is low and step-down converter is OFF. Once VIN value is reduced to 4.75V, PFI signal changes state to high, the step-down converter turns ON and starts to supply the LOAD rail by 5.0V taking energy from the storage capacitor C5. The efficiency curve is presented in Figure 4. The efficiency measurement was conducted in step-down mode. A constant DC voltage of 12V was applied to the VCAP and GND terminals with the input voltage disconnected from the VIN and GND terminals. VLOAD VLOAD VIN VIN 1V/DIV 1V/DIV PFI PFI DC2220 F03a 200µs/DIV 50ms/DIV 3a DC2220 F03b 3b Figure 3. Power interruption, VLOAD 5.0V, ILOAD 0.5A 96 95 EFFICIENCY (%) 94 93 92 91 90 89 88 87 86 0 0.5 1 1.5 2 LOAD CURRENT (A) 2.5 3 DC2220 F04 Figure 4. Efficiency vs Load, VCAP 12V, LOAD 5.0V, Step-Down Mode dc2220afb 3 DEMO MANUAL DC2220A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., X7R, 0.1µF, 25V, 10%, 0603 AVX, 06033C104KAT2A Required Circuit Components 1 1 C1 2 1 C2 CAP., X5R, 4.7µF,16V, 10%, 0805 TDK C2012X5R1C475K 3 1 C3 CAP., C0G, 470pF 50V, 5%, 0603 AVX, 06035A471JAT2A 4 1 C4 CAP., C0G, 22pF, 25V, 5%, 0603 AVX, 06033A220JAT2A 5 1 C5 CAP., ALUM., ELECT., 1000µF, 50V, 16x16.5 PANASONIC, EEEFK1H102AM 6 2 C9, C11 CAP., POS 47µF, 20V, 20%,TQC-D2 PANASONIC, 20TQC47MYF 7 1 C10 CAP., X7R, 4.7µF, 50V, 10%,1210 AVX, 12105C475KAT2A 8 3 C12, C13, C14 CAP., X7R, 10µF, 50V, 10%, 210 AVX, 12105C106KAT2A 9 1 C15 CAP., X7S, 1µF, 100V, 10%, 0805 TDK C2012X7S2A105K 10 1 L1 IND, 7.2µH POWER SUMIDA, CDEP105NP-7R2MC-88 11 1 Q1 MOSFET, P-CHN, 30V, LFPAK VISHAY, Si4491EDY-T1-GE3 12 1 R1 RES., CHIP, 511k, 1/10W, 1%, 0603 VISHAY, CRCW0603511KFKEA 13 1 R2 RES., CHIP, 0.01, 1/4W, 1%, 1206 VISHAY, WSL1206R0100FEA 14 1 R3 RES., CHIP, 133k, 1/16W, 1%, 0603 VISHAY, CRCW0603133KFKEA 15 1 R4 Res., CHIP, 1MEG, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA 16 1 R5 RES., CHIP, 37.4k, 1/10W, 1%, 0603 VISHAY, CRCW060337K4FKEA 17 2 R6, R11 RES., CHIP, 5.11k, 1/10W, 1%, 0603 VISHAY, CRCW06035K11FKEA 18 2 R7, R8 RES., CHIP, 510k, 1/10W, 1%, 0603 VISHAY, CRCW0603510KFKEA 19 1 R9 RES., CHIP, 402k, 1/10W, 1%, 0603 VISHAY, CRCW0603402K0FKEA 20 1 R10 RES., CHIP, 332k, 1/10W, 1%, 0603 VISHAY, CRCW0603332KFKEA 21 1 U1 I.C., LTC3643EUDD, QFN24UDD-3X5 LINEAR TECH., LTC3643EUDD#PBF Additional Demo Board Circuit Components 1 C6 CAP., ALUM. OPTION,16X16.5 OPT 2 C7, C8 CAP., OPTION, 0603 OPT 3 R12 RES., OPTION, 0603 OPT Hardware: For Demo Board Only 1 10 E1 – E10 TP, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 JP1 HEADER, 1X3, 0.079 SINGLE ROW WURTH, 620-003-111-21 3 1 JP2 HEADER, 1X4, 0.079 SINGLE ROW WURTH, 620-004-111-21 4 2 XJP1, XJP2 SHUNT, 0.079" CENTER WURTH, 608-002-134-21 4 dc2220afb 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 OFF ON E6 E5 E10 E9 E2 JP1 3 2 RUN 1 OPT R12 47uF + C9 C10 4.7uF 1210 Q1 R3 133K R1 511K INTVCC INTVCC R4 1MEG SI4491EDY 3 2 1 5 5 1. ALL RESISTORS AND CAPACITORS ARE 0603. NOTE: UNLESS OTHERWISE SPECIFIED /PFO CAPGD PFI GND GND 3V - 17V VIN E1 4 510K R8 510K R7 R6 5.11K R5 37.4K 4 C8 OPT 4 5 4 2 1 7 12 11 13 8 6 24 0.01 1210 R2 PGND PGND RUN /PFO CAPGD PFI FBSYS GATE CLP IN IN U1 LTC3643EUDD PGND SW SW SW INDIS INDIS 4A JP2 4 2A 3A 3 2 1 ILIM_BUCK 22 23 INTVCC C2 4.7uF 0805 C1 0.1UF L1 7.2uH 21 14 10 9 3 15 20 19 18 17 16 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 2 C4 22pF 2 SCALE = NONE VK LT ECO C12 10uF 1210 TECHNOLOGY 50V E7 OPT E8 GND CAP DATE: N/A SIZE LTC3643EUDD DEMO CIRCUIT 2220A Tuesday, September 01, 2015 IC NO. 1 SHEET 1 2 OF 1 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only C14 10uF 1210 GND + C6 1000uF + C5 DATE 9-01-15 LOAD 40V MAX E4 E3 VK APPROVED BIDIRECTIONAL HIGH VOLTAGE BACKUP CONVERTER TITLE: SCHEMATIC R11 5.11K R10 322K C7 OPT C15 1uF 100V 0805 C13 10uF 1210 5V SYSTEM BUS DESCRIPTION PRODUCTION 2 1 REVISION HISTORY REV 40V BACKUP 47uF + C11 APPROVALS C3 470pF R9 402K LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. CUSTOMER NOTICE NC NC ILIM INTVCC ITH FBCAP CAP BOOST 3 Figure 5. DC2220A Demo Circuit Schematic 25 5 A B C D DEMO MANUAL DC2220A SCHEMATIC DIAGRAM dc2220afb 5 DEMO MANUAL DC2220A 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 dc2220afb Linear Technology Corporation LT 0116 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2015