DEMO MANUAL DC2005A LTC3624EDD High Efficiency Synchronous Step-Down Regulator with Ultralow Quiescent Current DESCRIPTION Demonstration circuit DC2005A is a synchronous stepdown regulator using an LTC®3624 monolithic buck regulator. The DC2005A operates from an input voltage range of 2.7V to 17V and provides an adjustable output voltage range from 1.2V to 5V (VOUT < VIN) at 2A of output current. A user-selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency. Burst Mode® operation provides the highest efficiency at light load, while pulse-skipping mode provides the lowest voltage ripple. The MODE pin can also be used to sync the switching frequency to an external clock. The switching frequency is fixed at 1MHz or 2.25MHz with a ±40% synchronizing range. The regulator features ultralow quiescent current and high efficiency over a wide VOUT range. PERFORMANCE SUMMARY PARAMETER The DC2005A uses very low profile surface mount components and all ceramic output capacitors. The compact 8-lead DFN (3mm × 3mm) package makes the LTC3624 an excellent choice for battery-powered equipment, general purpose step-down power supply, and emergency radio applications. It is recommended to read the data sheet and demo manual of the LTC3624 prior using or making any changes to DC2005A. 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 Input Voltage Range VALUE 2.7V to 17V Onboard 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 Operation (BM) Default Switching Frequency Default Output Voltage, VOUT 1MHz 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 9.4mV (See Figure 5) Load Transient Response VIN = 12V, VOUT = 5V, IOUT = 1A to 2A See Figure 6 Thermal Image VIN = 12V, VOUT = 5V, IOUT = 2A, 1MHz See Figure 7 Efficiency VIN = 12V, VOUT = 5V, IOUT = 2A, BM, 1MHz 90.4% (See Figure 3 ) dc2005af 1 DEMO MANUAL DC2005A QUICK START PROCEDURE Demonstration circuit DC2005A is easy to set up to evaluate the performance of the LTC3624. Please refer to Figure1 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 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. 4.Connect the DMMs to the input and output to monitor the input voltage and output voltage. 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%. 7.To select other output voltages, use the on board user selectable output voltage jumpers. Shutting down LTC3624 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 steps 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 * Note: If JP8 is selected, R6 needs to be calculated and inserted to obtain the desired 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. Note 2: The DC2005A can also be used to evaluate LTC3624‑2 (2.25MHz) by simply changing U1 to LTC3624‑2 and L1 to 1.5µH (Coilcraft XAL4020-152ME). 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 ripple voltage, switch node waveform and other parameters. Refer to Figure 2 for proper input/ output voltage ripple measurement. dc2005af 2 DEMO MANUAL DC2005A QUICK START PROCEDURE Figure 1. Proper Equipment Measurement Setup Figure 2. Scope Probe Placements for Measuring Input or Output Ripple dc2005af 3 DEMO MANUAL DC2005A 100 100 90 90 EFFICIENCY (%) EFFICIENCY (%) QUICK START PROCEDURE 80 70 60 VIN = 12V IOUT = 0A TO 2A fSW = 1MHz 50 0.01 0.1 LOAD CURRENT (A) 1.2VOUT 1.8VOUT 2.5VOUT 3.3VOUT 5.0VOUT 1 80 VIN = 12V IOUT = 0A TO 2A fSW = 1MHz 1.2VOUT 1.8VOUT 2.5VOUT 3.3VOUT 5.0VOUT 70 60 50 2 0.5 0 1 1.5 2 LOAD CURRENT (A) Figure 3. Measured Efficiency in Burst Mode Operation (BM) Figure 4. Measured Efficiency in Forced Continuous Mode (FCM) 20MHz BW LIMIT VOUT 20mV/DIV VSW 10V/DIV VIN = 12V VOUT = 5V IOUT = 2A fSW = 1MHz 1µs/DIV Figure 5. Measured Output Voltage Ripple VP-P = 250mV VOUT 200mV/DIV IOUT 1A/DIV 1A TO 2A VIN = 12V VOUT = 5V IOUT = 1A 100µs/DIV Figure 6. Load Transient Response dc2005af 4 DEMO MANUAL DC2005A QUICK START PROCEDURE NO FORCED AIRFLOW TA = 24°C VIN = 12V VOUT = 5V IOUT = 2A fSW = 1MHz Figure 7. Thermal Performance dc2005af 5 DEMO MANUAL DC2005A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CFF CAP, 0402 15pF 5% 50V NPO AVX 04025A150JAT2A 2 1 CIN CAP, 47µF 20% 20V 33mΩ PANASONIC OSCON 20SVPA47M 3 2 C2,C3 CAP, 1206 22µF10% 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 MURATA GRM188R61A225KE34P 6 1 L1 IND, 3.3µH COILCRAFT XAL4030-332ME 7 2 R1, RSET RES, 0402 619k 1% 1/16W VISHAY CRCW0402619KFKED 8 1 R2 RES, 0402 309k 1% 1/16W VISHAY CRCW0402309KFKED 9 1 R3 RES, 0402 196k 1% 1/16W VISHAY CRCW0402196KFKEA 10 1 R4 RES, 0402 137k 1% 1/16W VISHAY CRCW0402137KFKED 11 1 R5 RES, 0402 84.5k 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 LTC3624EDD 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 RES, 0402 OPTION OPTION 5 0 R9, R10 RES, 0402 1MΩ 5% 1/16W OPTION VISHAY CRCW04021M00JNED OPTION 1 10 E1, E2, E3, E4, E5, E6, E7, E8, TURRET E9, E10 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 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 JP1, JP2, JP3 SHUNT, 2mm SAMTEC 2SN-BK-G Hardware MILL-MAX 2501-2-00-80-00-00-07-0 dc2005af 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. A B C D E6 E5 E4 E3 E7 E2 [2] [1] [2] PS OFF ON JP2 MODE BM FCM / SYNC INTVCC 47uF 20V + CIN [1] 4 3 2 1 JP1 RUN 3 2 1 [2] [2] R9 OPT R8 OPT C2 22uF 25V 1206 R10 OPT R11 1M INTVCC R7 0 6 7 C8 2.2uF 10V 0603 C7 OPT 3 C3 22uF 25V 1206 2 5 FOR FCM OPERATION, STUFF R9 AND R10 WITH 1MEG OHM RESISTOR. 4 MODE/SYNC INTVCC RUN VIN PGOOD FB SW 4 5 1 3 JP3 1.2V VOUT 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. JP5 2.5V R2 309k 1% APPROVALS JP4 1.8V R1 619k 1% 3.3uH L1 SCALE = NONE 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. MI VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. G LE APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. CUSTOMER NOTICE CIN IS AN OPTIONAL CAPACITOR. IT IS INSERTED ON THE DC2005A 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. NOTES: PGOOD GND SYNC INTVCC RUN GND E1 VIN 2.7V - 17V U1 LTC3624EDD (1MHz) GND 9 4 GND 8 5 R4 137k 1% C4 47uF 6.3V 1206 C5 OPT 1206 1 GND GND VOUT 2A E10 E9 C6 OPT 1210 E8 IC NO. 2 1 SHEET 1 LTC3624EDD DEMO CIRCUIT 2005A DATE: Tuesday, January 07, 2014 N/A SIZE 2 REV. OF 1 MONOLITHIC SYNCHRONOUS BUCK REGULATOR WITH ULTRA-LOW QUIESCENT CURRENT 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 TITLE: SCHEMATIC JP6 3.3V R3 196k 1% 2 A B C D DEMO MANUAL DC2005A SCHEMATIC DIAGRAM dc2005af 7 DEMO MANUAL DC2005A 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 dc2005af 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