DEMO MANUAL DC2359A LTC3624 High Efficiency Synchronous Step-Down Regulator with Ultralow Quiescent Current Description Demonstration circuit 2359A is a synchronous step-down regulator using LTC®3624HMSE monolithic buck regulator. The DC2359A operates from an input voltage range of 2.7V to 17V and provides and adjustable output voltage range from 1.2V to 5V (VOUT < VIN) at 2A of continuous output current. A user-selectable mode input is provided with the following options: Burst Mode® operation provides the highest efficiency at light loads, while Pulse-Skipping mode (PS) provides the lowest output voltage ripples. Forced Continuous mode (FC) is also available for low EMI and noise interference. The MODE/SYNC pin can also be used to synchronize the switching frequency to an external clock signal. The switching frequency is fixed at 1MHz with a ±40% sync capture range. The regulator features ultralow quiescent current and high efficiencies over a wide VIN and VOUT range. DC2359A Performance Summary PARAMETER uses very low profile surface mount components and all ceramic output capacitor solutions. The compact 12-lead MSE (5mm × 4mm × 1mm) thermally enhanced package makes LTC3624HMSE an excellent choice for battery powered equipment, emergency radio and general purpose step-down power supplies. The H-Grade version is specified over an operating junction temperature range of –40°C to 150°C, typically required for automotive, industrial and military applications that are subject to high ambient temperatures. It is recommended to read the data sheet and demo manual of LTC3624 prior using or making any changes to DC2359A. Design files for this circuit board are available at http://www.linear.com/demo/DC2359A 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 Input Voltage Range VALUE 2.7V to 17V On Board User Selectable Output Voltages VIN = 2.7V to 17V, IOUT = 2A (VOUT < VIN) 1.2V, 1.8V, 2.5V, 3.3V and 5V Default Mode Setting JP2 Burst Mode (“BM” on Circuit Board) Fixed Switching Frequency Internally Programmed Frequency 1MHz ±20% Default Output Voltage VOUT VIN = 12V, VOUT = 5V, IOUT = 0A to 2A 5V ±2% 2A Maximum Continuous Output Current IOUT Output Voltage Ripples (Peak to Peak) VIN = 12V, VOUT = 5V, IOUT = 2A 8.8mV (Figure 7) Load Transient Response VIN = 12V, VOUT = 5V, IOUT_STEP = 1A to 2A, COUT = 1 × 47µF 219mV (Figure 8) Thermal Performance VIN = 12V, VOUT = 5V, IOUT = 2A, fSW = 1MHz, TA = 25°C Figure 9 Efficiency VIN = 12V, VOUT = 5V, IOUT = 2A, BM, fSW = 1MHz, TA = 25°C 89.7% (Figure 3) dc2359afb 1 DEMO MANUAL DC2359A Quick Start Procedure Demonstration circuit 2359A is easy to set up to evaluate the performance of the LTC3624HMSE. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1.Place jumpers in the following positions for a typical 5V output application: Table 1. Typical 5V Output Voltage Jumper Selection JP1 JP2 JP7 RUN MODE/SYNC VOUT ON BM 5.0V 7.To select other output voltages, use the on board user selectable output voltage jumpers. Shutting down LTC3624HMSE by placing RUN pin jumper (JP1) to the OFF position or turn off the input power supply. Refer to the following table (Table 2) for the output voltage selection and repeat step 2 to 6. Table 2. Output Voltage Jumper Selection JP3 JP4 JP5 JP6 JP7 JP8* 1.2V 1.8V 2.5V 3.3V 5V User Select *If JP8 is selected, R6 needs to be calculated and inserted to obtain the desired output voltage. 4.Connect the DMMs to the input and output to monitor the input voltage and output voltage. NOTE 1: To measure the input/output voltage ripple properly, do not use the long ground lead on the oscilloscope probe. See Figure 2 for the proper scope probe technique. Short, stiff leads need to be soldered to the (+) and (–) terminals of an output capacitor. The probe’s ground ring needs to touch the (–) lead and the probe tip needs to touch the (+) lead. 5.Turn on the power supply at the input. The RUN pin jumper should be at “ON” position. Measure and make sure the input supply voltage is 12V. The output voltage should be 5V ±2%. NOTE 2: The DC2359A can also be used to evaluate the LTC3624HMSE-2 (2.25MHz) by simply replacing U1 with the LTC3624HMSE-2 and changing inductor L1 to 1.5µH (Coilcraft XAL4020-152ME). 2.With power off, connect the input power supply at VIN (E1) and GND (E2) 3.Connect the Load between VOUT (E8) and GND (E9). Preset the load to 0A. 6.Once the input and output voltages are properly established, adjust the loads within the operating range (0A to 2A Max) and observe the output voltage regulation, output voltage ripple, switch node waveform and other parameters. Refer to Figure 2 for proper output voltage ripple measurement. dc2359afb 2 DEMO MANUAL DC2359A Quick Start Procedure Figure 1. Proper Measurement Equipment Setup + VOUT – COUT GND Figure 2. Scope Probe Placement for Measuring Output Voltage Ripple dc2359afb 3 DEMO MANUAL DC2359A 100 100 95 95 90 90 85 85 80 75 70 65 1.2VOUT 1.8VOUT 2.5VOUT 3.3VOUT 5.0VOUT 60 55 50 0.01 0.10 LOAD CURRENT (A) EFFICIENCY (%) EFFICIENCY (%) Quick Start Procedure 80 75 70 1.2VOUT 1.8VOUT 2.5VOUT 3.3VOUT 5.0VOUT 65 60 55 50 0.0 1.00 1.10 0.5 DC2359a F04 DC2359a F03 Figure 4. Forced Continuous Mode – Efficiency vs Load Current at 12VIN 100 100 95 95 90 90 85 85 EFFICIENCY (%) EFFICIENCY (%) Figure 3. Burst Mode – Efficiency vs Load Current at 12VIN 80 75 70 65 1.2VOUT 1.8VOUT 2.5VOUT 3.3VOUT 60 55 50 0.01 0.10 LOAD CURRENT (A) 1.00 1.10 DC2359a F05 Figure 5. Burst Mode – Efficiency vs Load Current at 5VIN 2.0 1.0 1.5 LOAD CURRENT (A) 80 75 70 65 1.2VOUT 1.8VOUT 2.5VOUT 3.3VOUT 60 55 50 0.0 0.5 1.0 1.5 LOAD CURRENT (A) 2.0 DC2359a F06 Figure 6. Forced Continuous Mode – Efficiency vs Load Current at 5VIN dc2359afb 4 DEMO MANUAL DC2359A Quick Start Procedure 20MHz BW LIMIT VP-P = 8.8mV VOUT 20mV/DIV VSW 10V/DIV t(1µs/DIV) DC2359a F07 fSW = 1MHz VIN = 12V VOUT = 5V ILOAD = 2A L = 3.3µH COUT = 1x 47µF/6.3V/X5R/1206 Figure 7. Measured Output Voltage Ripple dc2359afb 5 DEMO MANUAL DC2359A Quick Start Procedure 20MHz BW LIMIT VP-P = 219mV VOUT 200mV/DIV 1A TO 2A IOUT 1A/DIV t(50µs/DIV) DC2359a F08 fSW = 1MHz VIN = 12V VOUT = 5V ILOAD = 1A TO 2A L = 3.3µH COUT = 1x 47µF/6.3V/X5R/1206 CFF = 15pF Figure 8. Load Transient Response dc2359afb 6 DEMO MANUAL DC2359A Quick Start Procedure DC2359a F09 VIN = 12V VOUT = 5V ILOAD = 2A L = 3.3µH fSW = 1MHz NO FORCED AIRFLOW TA = 25°C Figure 9. Thermal Performance dc2359afb 7 DEMO MANUAL DC2359A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CFF CAP, 0402 15pF 1% 50V NPO AVX 04025U150FAT2A 2 1 CIN CAP, 47μF 20% 20V 33mΩ PANASONIC OSCON 20SVPA47M 3 2 C2, C3 CAP, 1206 22μF 10% 25V X5R MURATA GRM31CR61E226KE15L 4 1 C4 CAP, 1206 47μF 20% 6.3V X5R TAIYO YUDEN JMK316BJ476ML-T 5 1 C8 CAP, 0603 2.2μF 10% 10V X5R AVX 0603ZD225KAT2A 6 1 L1 IND, 3.3μH XAL4030-332ME 7 2 R1, RSET RES, 0402 619kΩ 1% 1/16W VISHAY CRCW0402619KFKED 8 1 R2 RES, 0402 309kΩ 1% 1/16W VISHAY CRCW0402309KFKED 9 1 R3 RES, 0402 196kΩ 1% 1/16W VISHAY CRCW0402196KFKEA 10 1 R4 RES, 0402 137kΩ 1% 1/16W VISHAY CRCW0402137KFKED 11 1 R5 RES, 0402 84.5kΩ 1% 1/16W VISHAY CRCW040284K5FKED 12 2 R7, R12 RES, 0402 0Ω JUMPER VISHAY CRCW04020000Z0ED 13 1 R11 RES, 0402 1MΩ 5% 1/16W VISHAY CRCW04021M00JNED 14 1 U1 IC, MONOLITHIC SYNCHRONOUS BUCK REGULATOR LINEAR TECH LTC3624HMSE#PBF Additional Demo Board Circuit Components 1 0 C5 CAP, 1206 22μF 20% 6.3V X5R OPTION TAIYO YUDEN EMK316BJ226ML-T OPTION 2 0 C6 CAP, 1210 OPTION OPTION 3 0 C7 CAP, 0402 OPTION OPTION 4 0 R6, R8, R9, R10 RES, 0402 OPTION OPTION 1 10 E1, E2, E3, E4, E5, E6, E7, E8, E9, E10 TURRET MILL-MAX 2501-2-00-80-00-00-07-0 2 1 JP1 HEADER, 3-PIN, 2mm SAMTEC TMM-103-02-L-S 3 1 JP2 HEADER, 4-PIN, 2mm SAMTEC TMM-104-02-L-S Hardware 4 6 JP3, JP4, JP5, JP6, JP7, JP8 HEADER, 2-PIN, 2mm SAMTEC TMM 102-02-L-S 5 4 MH1, MH2, MH3, MH4 STANDOFF, SNAP ON KEYSTONE 8833 6 3 XJP1, XJP2, XJP7 SHUNT, 2mm SAMTEC 2SN-BK-G dc2359afb 8 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 E6 E5 E4 E3 E7 9 10 C8 2.2uF 10V 0603 C7 OPT 5 4 MODE/SYNC INTVCC RUN VIN VIN 7 6 8 2 1 JP4 1.8V 3 `\ SCALE = NONE Z_ JP6 3.3V R3 196k 1% R4 137k 1% 2 C4 47uF 6.3V 1206 C5 OPT 1206 E10 E9 C6 OPT 1210 E8 GND GND IC NO. 2 1 SHEET 1 LTC3624HMSE DEMO CIRCUIT 2359A DATE: Wednesday, August 12, 2015 N/A SIZE 2A VOUT ADJ OF 1 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 JP8 USER SELECT R6 OPT CFF 15pF TECHNOLOGY JP7 5.0V R5 84.5K 1% RSET 619k 1% R12 0 1 MONOLITHIC SYNCHRONOUS BUCK REGULATOR WITH ULTRA-LOW QUIESCENT CURRENT TITLE: SCHEMATIC JP5 2.5V R2 309k 1% APPROVALS JP3 1.2V R1 619k 1% 3.3uH L1 Coilcraft XAL4030-332ME VOUT THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE NC PGOOD FB SW SW 3 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. FOR FCM OPERATION, STUFF R9 AND R10 WITH 1MEG OHM RESISTOR. R11 1Meg INTVCC [2] R10 OPT [2] R9 OPT R8 OPT 5 4 [2] 4 3 2 1 JP1 3 2 1 C3 22uF 25V 1206 CIN IS AN OPTIONAL CAPACITOR. IT IS INSERTED ON THE DC2359A TO DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO THE LONG INPUT LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, THE CAPACITOR IS NOT NEEDED. PS JP2 MODE BM [2] FCM / SYNC INTVCC OFF ON RUN R7 0 C2 22uF 25V 1206 [1] NOTES: PGOOD GND SYNC INTVCC RUN GND E2 47uF 20V + CIN [1] 3 U1 LTC3624HMSE (1MHz) GND 11 E1 VIN 2.7V - 17V 4 GND 12 5 A B C D DEMO MANUAL DC2359A Schematic Diagram dc2359afb 9 DEMO MANUAL DC2359A 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 dc2359afb 10 Linear Technology Corporation LT 1015 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