DEMO MANUAL DC1596A LTC3607EUD Dual 600mA 15V Monolithic Synchronous Step-Down Regulator DESCRIPTION Demonstration circuit DC1596 is a dual output regulator consisting of two constant-frequency step-down converters, based on the LTC®3607 monolithic dual channel synchronous buck regulator. The DC1596 has an input voltage range of 4.5V to 15V, with each regulator capable of delivering up to 600mA of output current. The DC1596 can operate in either Burst Mode® operation or pulse-skipping mode. In shutdown, the DC1596 quiescent current is less than 1µA. The DC1596 is a very efficient circuit attaining up to 90%. The DC1596 uses the LTC3607’s16-lead QFN PERFORMANCE SUMMARY PARAMETER package, which has an exposed pad on the bottom side of the IC for better thermal performance. These features, plus a set operating frequency range of 2.25MHz, make the DC1596 demo board an ideal circuit for industrial or distributed power applications. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C CONDITIONS VALUE Minimum Input Voltage 4.5V Maximum Input Voltage 15V Run RUN Pin = GND RUN Pin = VIN Shutdown Operating Output Voltage VOUT1 Regulation VIN1 = 4.5V to 15V, IOUT1 = 0A to 600mA 1.2V ±4% (1.152V-1.148V) 1.5V ±4% (1.44V-1.56V) 1.8V ±4% (1.728V-1.872V) Typical Output Ripple VOUT1 VIN1 = 12V, IOUT1 = 600mA (20MHz BW) <20mVP-P Output Voltage VOUT2 Regulation VIN2 = 4.5V to 15V, IOUT2 = 0A to 600mA 2.5V ±4% (2.425V-2.6V) 3.3V ±4% (3.168V-3.432V) 5V ±4% (4.8V-5.2V) Typical Output Ripple VOUT2 VIN2 = 12V, IOUT2 = 600mA (20MHz BW) <20mVP-P Mode Setting Mode Pin Floating Mode Pin Grounded Burst Mode Operation Pulse-Skipping Burst Mode Operation Output Current Thresholds Channel 1: PVIN1 = 12V, VOUT1 = 1.8V Channel 2: PVIN2 = 12V, VOUT2 = 3.3V IOUT1 < 480mA IOUT2 < 360mA Pulse-Skipping Operation Output Current Thresholds Channel 1: PVIN1 = 12V, VOUT1 = 1.8V Channel 2: PVIN2 = 12V, VOUT2 = 3.3V IOUT1 < 330mA IOUT2 < 240mA Switching Frequency 2.25MHz ±20% dc1596afa 1 DEMO MANUAL DC1596A QUICK START PROCEDURE The DC1596 is easy to set up to evaluate the performance of the LTC3607. For a proper measurement equipment configuration, set up the circuit according to the diagram in Figure 1. 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 the proper scope probe technique in Figure 2. 5.Set the load current of both outputs to 600mA and the input voltages to 12V, and then measure each output ripple voltage (refer to Figure 2 for proper measurement technique); they should each measure less than 20mVAC. Also, observe the voltage waveform at either switch node (Pin 5 for reg.1 and Pin 8 for reg.2) of each regulator. The switching frequencies should be about 2.25MHz ±20% (T = 555ns and 370ns). Both switch node waveforms should be rectangular in shape, and 180° out-of-phase with each other. Please follow the procedure outlined below for proper operation. 6.To operate the ckt.s in Burst Mode operation, change the shunt position of header JP3 to BURST MODE. 1.Connect the input power supply to the PVIN1/PVIN2 and GND terminals (VIN1 and VIN2 are separate nodes but are connected). Connect the loads between the VOUT and GND terminals. Refer to Figure 1 for the proper measurement equipment setup. 7.Regulators 1 (PVIN1) and 2 (PVIN2) are completely separated from each other; thus, they can be powered from different individual input supplies (if R11 is removed), as can the signal input supply, SVIN. However, SVIN must powered for either regulator to function (SVIN is connected to PVIN1 through a filter on the demo board.). Before proceeding to operation, insert jumper shunts XJP1 and XJP2 into the OFF positions of headers JP1 and JP2, shunt XJP3 into the pulse-skip position of MODE header JP3, and shunt XJP4 into the VOUT1 voltage options of choice of header JP4: 1.2V, 1.5V, or 1.8V, and shunt XJP5 into the VOUT2 voltage options of choice of header JP5: 2.5V, 3.3V, or 5V. 2.Apply 5.5V at PVINs 1, 2. Measure both VOUTs; they should read 0V. If desired, one can measure the shutdown supply current at this point. The supply current will be less than 1µA in shutdown. 3.Turn on VOUT1 and VOUT2 by shifting shunts XJP1 and XJP2 from the OFF positions to the ON positions. Both output voltages should be within a tolerance of ±2%. 8.When finished, insert shunts XJP1 and XJP2 to the OFF position(s) and disconnect the power. Warning: If the power for the demo board is carried in long leads, the input voltage at the part could “ring”, which could affect the operation of the circuit or even exceed the maximum voltage rating of the IC. To eliminate the ringing, a small tantalum capacitor (for instance, AVX part # TPSY226M035R0200) is inserted on the pads between the input power and return terminals on the bottom of the demo board. The (greater) ESR of the tantalum capacitor will dampen the (possible) ringing voltage caused by the long input leads. On a normal, typical PCB, with short traces, this capacitor is not needed. 4.Vary the input voltages from 5.8V (the minimum VIN is dependent on VOUT) to 15V, and the load currents from 0A to 600mA. Both output voltages should be within ±4% tolerance. dc1596afa 2 DEMO MANUAL DC1596A QUICK START PROCEDURE Figure 1. Proper Measurement Equipment Setup VIN GND Figure 2. Measuring Input or Output Ripple dc1596afa 3 DEMO MANUAL DC1596A QUICK START PROCEDURE VSW1 10V/DIV VOUT 100mV/DIV AC-COUPLED VOUT1 20mV/DIV AC VOLTAGE IOUT 200mA/DIV VSW2 10V/DIV VOUT2 20mV/DIV AC VOLTAGE 200ns/DIV PVIN1,2 = 12V VOUT1 = 1.8V AT IOUT1 = 600mA VOUT2 = 3.3V AT IOUT2 = 600mA PULSE-SKIPPING MODE DC1596A F03 20µs/DIV VIN = 12V VOUT1 = 1.2V 400mA LOAD STEP (200mA TO 600mA) PULSE-SKIPPING MODE, fSW = 2.25MHz Figure 3. Switch Operation Figure 4. Load Step Response VOUT 100mV/DIV AC-COUPLED VOUT 100mV/DIV AC-COUPLED IOUT 200mA/DIV IOUT 200mA/DIV 20µs/DIV VIN = 12V VOUT1 = 1.5V 400mA LOAD STEP (200mA TO 600mA) PULSE-SKIPPING MODE, fSW = 2.25MHz DC1596A F04 DC1596A F05 Figure 5. Load Step Response 20µs/DIV VIN = 12V VOUT1 = 1.8V 400mA LOAD STEP (200mA TO 600mA) PULSE-SKIPPING MODE, fSW = 2.25MHz DC1596A F06 Figure 6. Load Step Response dc1596afa 4 DEMO MANUAL DC1596A QUICK START PROCEDURE VOUT 100mV/DIV AC-COUPLED VOUT 100mV/DIV AC-COUPLED IOUT 200mA/DIV IOUT 200mA/DIV 20µs/DIV VIN = 12V VOUT2 = 2.5V 400mA LOAD STEP (200mA TO 600mA) PULSE-SKIPPING MODE, fSW = 2.25MHz 20µs/DIV VIN = 12V VOUT2 = 3.3V 400mA LOAD STEP (200mA TO 600mA) PULSE-SKIPPING MODE, fSW = 2.25MHz DC1596A F07 Figure 7. Load Step Response DC1596A F08 Figure 8. Load Step Response 100 VOUT 100mV/DIV AC-COUPLED 90 EFFICIENCY (%) 80 IOUT 200mA/DIV 20µs/DIV VIN = 12V VOUT2 = 5V 400mA LOAD STEP (200mA TO 600mA) PULSE-SKIPPING MODE, fSW = 2.25MHz DC1596A F09 Figure 9. Load Step Response 70 60 50 40 30 20 0000.1 L1: 2.2µH 1616BZ VISHAY L2: 4.7µH 1616BZ VISHAY Burst Mode OPERATION fSW = 2.25MHz VIN = 5V, VO1 = 1.8V VIN = 12V, VO1 = 1.8V VIN = 5V, VO2 = 3.3V VIN = 12V, VO2 = 3.3V 00.1 000.1 0.1 LOAD CURRENT (A) 1 DC1596A F10 Figure 10. Efficiency dc1596afa 5 DEMO MANUAL DC1596A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 CFFW1, CFFW2 CAP., NPO, 22pF, 25V, 5%, 0402 AVX, 04025A220JAT2A 2 2 CIN1BYP, CIN2BYP CAP., X7R, 0.1µF, 16V, 10%, 0603 AVX, 0603YC104KAT2A 3 2 COUT1, COUT2 CAP., X5R, 10µF, 6.3V, 10%, 0805 AVX, 08056D106KAT2A 4 2 CIN1, CIN2 CAP., X5R, 10µF, 16V, 10%, 1206 AVX, 1206YD106KAT2A 5 1 L1 Inductor, 2.2µH VISHAY, IHLP1616BZER2R2M11 6 1 L2 Inductor, 4.7µH VISHAY, IHLP1616BZER4R7M11 7 1 R1 RES., CHIP, 210k, 1%, 0402 VISHAY, CRCW0402210KFKED 8 1 R2 RES., CHIP, 887k, 1%, 0402 VISHAY, CRCW0402887KFKED 9 1 R6 RES., CHIP, 196k, 1%, 0402 VISHAY, CRCW0402196KFKED 10 1 R7 RES., CHIP, 105k, 1%, 0402 VISHAY, CRCW0402105KFKED 11 1 U1 IC., LTC3607EUD, 16-PIN QFN 3X3 LINEAR TECH., LTC3607EUD Additional Demo Board Circuit Components 1 3 COUT3, COUT4, CF CAP., X7R, 0.1µF, 16V, 10%, 0603 AVX, 0603YC104KAT2A 2 2 CIN3, CIN4 CAP., TANT, 22µF, 35V, 20%, CASE Y AVX, TPSY226M035R0200 3 0 COUT5, COUT6 (OPT.) CAP., X5R, 47µF, 6.3V, 10%, 1210 AVX, 12106D476KAQ2A 4 0 CIN5, CIN6 (OPT.) CAP., X5R, 47µF, 20V, 10%, 1812 5 1 RF RES., CHIP, 100Ω, 1/16W, 5%, 0402 VISHAY, CRCW0402100RJNED 6 1 R3 RES., CHIP, 210k, 1%, 0402 VISHAY, CRCW0402210KFKED 7 1 R4 RES., CHIP, 280k, 1%, 0402 VISHAY, CRCW0402280KFKED 8 1 R5 RES., CHIP, 140k, 1%, 0402 VISHAY, CRCW0402140KFKED VISHAY, CRCW0402105KFKED 9 1 R8 RES., CHIP, 121k, 1%, 0402 10 0 R9, R10 (OPT.) RES., 0402 11 1 R11 RES., CHIP, 0Ω, 1%, 0805 VISHAY, CRCW08050000Z0ED 12 2 RSD1, RSD2 RES., CHIP, 5.1M, 5%, 0402 VISHAY, CRCW04025M10JNED 13 2 RPG1, RPG2 RES., CHIP, 100k, 1%, 0402 VISHAY, CRCW0402100KFKED 1 12 E1-E12 Testpoint, TURRET, 0.094" MILL-MAX-2501-2-00-80-00-00-07-0 2 2 JP1,JP2 0.079 SINGLE ROW HEADER, 3-PIN SAMTEC, TMM103-02-L-S 3 2 JP4,JP5 0.079, 2X4 HEADER SAMTEC, TMM104-02-L-D 4 1 JP3 0.079, 2X3 HEADER SAMTEC, TMM103-02-L-D 5 5 JP1-JP5 SHUNT, FOR JP1-JP5 SAMTEC, 2SN-BK-G Hardware dc1596afa 6 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 2 3 E11 E9 E7 E4 E6 E3 1 3 5 7 JP4 VFB1 COUT3 0.1uF 16V 2 4 6 8 CIN1 10uF 16V A 2 1 RSD1 5.1M SW1 PGOOD1 MODE/SYNC LTC3607EUD U1 CF 0.1uF SW2 PGOOD2 APPROVALS TITLE: SCHEMATIC R2 887k 1% C THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. TG APP ENG. SCALE = NONE HZ 1 3 5 7 CFFW2 22pF * E8 E5 E2 2.5V 3.3V 5V USER SELECT E12 E10 COUT4 0.1uF 16V + CIN4 22uF 35V TOM G. DATE 3-15-13 GND GND VOUT2 600mA PGOOD2 PVIN2 4.5V - 15V APPROVED E DATE: N/A SIZE D LTC3607EUD DEMO CIRCUIT 1596A Thursday, May 16, 2013 IC NO. E SHEET 1 2 OF 1 REV. DUAL 600mA MONOLITHIC, SYNCHRONOUS STEP-DOWN REGULATOR 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only 2 4 6 8 COUT6 47uF 6.3V OPT + CIN6 47uF 20V OPT JP5 VFB2 RPG2 100k CIN2 10uF 16V TECHNOLOGY R10 OPT R9 OPT PCB DES. R8 121k 1% CUSTOMER NOTICE COUT2 10uF 6.3V CIN2BYP 0.1uF 16V R7 105k 1% 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. L2 4.7uH OFF ON Vishay IHLP-1616BZER4R7M11 8 11 RSD2 5.1M 1 2 3 JP2 RUN2 R6 196k 1% 5 Vishay IHLP-1616BZER2R2M11 L1 2.2uH 2 4 6 1 2 3 RF 100 DESCRIPTION REVISION HISTORY PRODUCTION R5 140k 1% B 1 3 5 JP1 RUN1 2 REV R4 280k 1% R1 210k 1% ON OFF JP3 MODE/SYNC COUT1 10uF 6.3V BURST MODE PULSE-SKIP EXT SYNC CIN1BYP 0.1uF 16V __ ECO D R3 210k 1% CFFW1 22pF RPG1 100k COUT5 47uF 6.3V OPT + CIN5 47uF 20V OPT [*] CIN3 AND CIN4 ARE INSERTED ON DC1596A TO DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUETO THE USE OF LONG INPUT LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, CIN3 AND CIN4 ARE NOT NEEDED. 1.2V 1.5V 1.8V USER SELECT GND GND VOUT1 600mA PGOOD1 SYNC GND + CIN3 22uF 35V VFB1 15 * PGND1 4 E1 GND 17 PVIN1 SGND SGND 10 12 4.5V - 15V R11 0 Ohm 0805 9 4 16 RUN1 3 SVIN 6 PVIN1 C 7 PGND2 B 13 RUN2 PVIN2 VFB2 14 A 1 2 3 4 DEMO MANUAL DC1596A SCHEMATIC DIAGRAM dc1596afa 7 DEMO MANUAL DC1596A 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 dc1596afa 8 Linear Technology Corporation LT 0114 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013