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DC1839A

DC1839A

  • 厂商:

    LINEAR(凌力尔特)

  • 封装:

    -

  • 描述:

    EVAL BOARD BUCK REG LTC3634

  • 详情介绍
  • 数据手册
  • 价格&库存
DC1839A 数据手册
DEMO MANUAL DC1839A LTC3634 15V Dual 3A Monolithic Step-Down Regulator Board for DDR Power DESCRIPTION Demonstration circuit 1839A is a dual output regulator focused specifically for DDR memory power applications. It’s built based on the LTC3634, a high voltage dual channel, controlled on-time monolithic synchronous buck regulator. The DC1839A has an input voltage range of 3.6V to 15V. The output voltage of the first channel, VDDQ, of the DC1839A has three fixed voltage settings; 1.5V, 1.8V, and 2.5V, and is capable of delivering up to 3A of output current. The second channel, V TT, is set to regulate to half the voltage on the VDDQIN pin, which can be either the channel 1 output or an external reference voltage. It can source or sink a maximum of 3A. The LTC3634 also provides a 10mA buffered output of half VDDQIN – VTTR, which is used to provide the reference voltage needed for DDR applications. With the use of a timing resistor, the DC1839A can have its operating frequency programmed from 500kHz to 4MHz, or the DC1839A can be easily synchronized to an external clock, due to an internal phase-locked loop. The DC1839A VDDQ output can operate in either Burst Mode® operation or PERFORMANCE SUMMARY PARAMETER forced continuous mode. In Burst Mode operation, which is the preferred mode of low load current operation, the DC supply current is typically only 1.3mA (both channels) at no load (sleep mode), and less than 15μA in shutdown. In Burst Mode operation or continuous mode operation, the DC1839A is a very efficient circuit at high load currents: over 80% for either channel. The LTC3634 is also capable of in-phase or 180° out-of-phase operation, and to allow its output to track an external voltage, either coincidentally or ratiometrically. The LTC3634 comes in a 28-pin QFN or leaded package, which each having an exposed pad on the bottom side of the IC for better thermal performance. All of these features make the DC1839A an ideal circuit for powering DDR memory applications. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, μModule, 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. (TA = 25°C) CONDITIONS VALUE Minimum Input Voltage 3.6V Maximum Input Voltage Output Voltage VOUT1 – VDDQ 15V VIN = 3.6V to 15V, IOUT1 = 0A to 3A 1.5V ±2% (1.47V to 1.53V) 1.8V ±2% (1.764V to 1.836V) 2.5V ±2% (2.45V to 2.55V) Typical Output Ripple VDDQ VIN = 12V, IOUT1 = 3A (20MHz BW) Output Voltage VOUT2 – V TT VIN = 3.6V to 15V, IOUT2 = 0A to ±3A < 20mVP-P VOUT1 = 1.5V 0.75V ±3% (0.7275V to 0.7725V) VOUT1 = 1.8V 0.9V ±3% (0.873V to 0.927V) VOUT1 = 2.5V 1.25V ±3% (1.2125V to 1.2875V) Typical Output Ripple V TT VIN = 12V, IOUT2 = ±3A (20MHz BW) < 20mVP-P Nominal Switching Frequencies RT = 324k 1MHz Burst Mode-to-CCM transition Channel 1: VIN = 12V, VOUT1 = 1.8V, fSW = 1 MHz IOUT1 = 1.6A 3.3V INTVCC VTTR VDDQIN = 2.5V 1.25V dc1839af 1 DEMO MANUAL DC1839A QUICK START PROCEDURE The DC1839A is easy to set up to evaluate the performance of the LTC3634. 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. Please follow the procedure outlined below for proper operation. 1. Connect the input power supply to the VIN and GND terminals. Connect the loads between the VOUT and GND terminals. Refer to Figure 1 for the proper measurement equipment setup. Before proceeding to operation, insert jumper shunts XJP1 and XJP2 into the OFF positions of headers JP1 and JP2, shunt XJP3 into the forced continuous mode (FCM) position of MODE header JP3, shunt XJP4 into the 180° (out-of-phase) position of PHASE header JP4, shunt XJP5 into the soft-start positions of TRACK/SS header JP5, and shunt XJP6 into the VOUT1 voltage options of choice of header JP6: 1.2V, 1.5V, or 1.8V. 2. Apply 5V at VIN. Measure both VOUTs; they should read 0V. If desired, one can measure the shutdown supply current at this point. The supply current should be less than 30μA in shutdown. 3. Turn on VOUT1, VDDQ, and VOUT2, VTT, by shifting shunts XJP1 and XJP2 from the OFF positions to the ON positions. Both output voltages should be within a tolerance of ±1%. 4. Vary the input voltage from 3.6V to 15V, the channel 1 load current from 0 to 3A, and the channel 2 load current from 0 to ±3A (The VTT channel sinks as well as sources current. An easy way to test this capability is shown in the test set-up diagram; connect a variable resistor from VIN to VOUT, along with an ampmeter. The current will be VIN minus VOUT divided by the variable resistor value). VDDQ output voltage tolerance should be within ±2%, whereas the output voltage tolerance of VTT should be within ±3%. 5. Set the load current of both outputs to 3A and the input voltage to 12V, 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 (pins 16 and 17 for channel 1, and 23 and 24 for channel 2) of each regulator. (Both switch node waveforms should be rectangular in shape and 180°out-of-phase with each other). The switching frequencies should be between 800kHz and 1.2MHz (T = 1.25μs and 0.833μs). 6. With the board under proper operation, observe the load regulation, efficiency, in-phase operation (by changing jumper XJP4 to the 90° position), or Burst Mode operation (by changing jumper XJP3 to the Burst Mode position). 7. (Optional) Moving the zero ohm resistor at RVDDQ, inserting it into RDDQIN, and applying a voltage to turret VDDQIN allows channel 2 output voltage (VTTR) to be adjusted to any desired voltage (to one-half the voltage at VDDQIN). 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 Poscap capacitor (for instance, AVX part number 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 Poscap will dampen the (possible) ringing voltage due to the use of long input leads. On a normal, typical PCB, with short traces, this capacitor is not needed. dc1839af 2 DEMO MANUAL DC1839A QUICK START PROCEDURE VS VARIABLE RESISTOR Figure 1. Proper Measurement Equipment Setup dc1839af 3 DEMO MANUAL DC1839A QUICK START PROCEDURE GND VIN Figure 2. Measuring Input or Output Ripple 100 90 EFFICIENCY (%) 80 70 60 50 VIN = 12V VDDQ = 2.5V V TT = 1.25V fSW = 1MHz Burst Mode OPERATION L1 = 1μH L2 = 0.47μH VISHAY 2020BZ 40 30 20 10 0 0 0.5 1.0 1.5 2.0 LOAD CURRENT (A) 2.5 3.0 dc1839a F03 Figure 3. LTC3634 DC1839A Efficiency dc1839af 4 DEMO MANUAL DC1839A QUICK START PROCEDURE dc1839a F05 dc1839a F04 VIN = 12V VDDQ = 1.8V 3A LOAD STEP (0A TO 3A) FORCED CONTINUOUS MODE fSW = 1MHz EXTERNAL COMPENSATION: RITH1 = 18.2k, CITH1 = 680pF TRACE 3: OUTPUT VOLTAGE (50mV/DIV AC) TRACE 4: OUTPUT CURRENT (1A/DIV) Figure 4. VDDQ Load Step Response VIN = 12V VTT = 0.9V ±3A LOAD STEP (–3A TO 3A) FORCED CONTINUOUS MODE fSW = 1MHz EXTERNAL COMPENSATION: RITH2 = 15k, CITH2 = 1000pF TRACE 3: OUTPUT VOLTAGE (50mV/DIV AC) TRACE 4: OUTPUT CURRENT (2A/DIV) Figure 5. V TT Load Step Response dc1839a F06 VIN = 12V VDDQ = 1.8V V TT = 0.9V 3A LOAD (EACH) FORCED CONTINUOUS MODE fSW = 1MHz CSS = 4700pF TRACE 1: VDDQ OUTPUT (500mV/DIV) TRACE 2: V TT OUTPUT (500mV/DIV) TRACE 3: VTTR OUTPUT (1V/DIV) TRACE 4: VRUN VOLTAGE (2V/DIV) Figure 6. LTC3634 DC1839A Start-Up with Soft-Start dc1839af 5 DEMO MANUAL DC1839A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 CBST1, CBST2 CAP, 0603, 0.1μF, 10%, 50V, X7R NIC NMC0603X7R104K50TRPF 2 1 CFFW1 CAP, 0402, 10pF, 5%, 25V, NPO NIC NMC0402NPO100J25TRPF 3 2 CIN1, CIN2 CAP, 1210, 47μF, 20%, 16V, X5R TAIYO YUDEN EMK325BJ476MM-T 4 1 CITH1 CAP, 0402, 680pF, 10%, 25V, X7R AVX 04023C681KAT2A 5 1 CITH2 CAP, 0402, 1000pF, 10%, 25V, X7R AVX 04023C102KAT2A 6 5 COUT1-COUT4, COUT6 CAP, 1812, 100μF, 20%, 6.3V, X5R TDK C4532X5R0J107M 7 1 CTTR CAP, 0603, 10nF, 10%, 16V, X7R AVX 0603YC103KAT2A 8 1 CVCC CAP, 0603, 1μF, 10%, 16V, X5R NIC NMC0603X5R105K16TRPF 9 1 L1 IND, 1.0μH VISHAY IHLP2020BZER1R0M01 10 1 L2 IND, 0.47μH VISHAY IHLP2020BZERR47M01 11 1 RFB1 RES, 0402, 34.8kΩ, 1%, 1/16W NIC NRC04F3482TRF 12 1 RITH1 RES, 0402, 18.2kΩ, 1%, 1/16W VISHAY CRCW040218K2FKED 13 1 RITH2 RES, 0402, 15kΩ, 1%, 1/16W VISHAY CRCW040215K0FKED 14 1 RT RES, 0402, 324kΩ, 1%, 1/16W NIC NRC04F3243TRF 15 1 RVDDQ RES, 0402, 0Ω, JUMPER NIC NRC04Z0TRF 16 1 R3 RES, 0402, 11kΩ, 1%, 1/16W NIC NRC04F1102TRF 17 1 U1 IC, MONOLITHIC SYNCHRONOUS STEP-DOWN REGULATOR LINEAR TECH LTC3634EFE Additional Demo Board Circuit Components 1 0 CC1, CC2 OPTION CAP, 0402, 10pF, 5%, 25V, NPO NIC NMC0402NPO100J25TRPF 2 0 CDDQIN OPTION CAP, 0805, 10μF, 10%, 6.3V, X5R OPTION NIC NMC0805X5R106K6.3TRPLP3KF 3 0 CIN3, CIN4 OPTION CAP, 1210, 47μF, 20%, 16V, X5R TAIYO YUDEN EMK325BJ476MM-T 4 2 CIN5, CIN6 CAP, TANT. 7343, 22μF, 20%, 35V AVX TPSY226M035R0200 5 0 COUT5, COUT8 OPTION CAP, 1812, 100μF, 20%, 6.3V, X5R TDK C4532X5R0J107M OPTION 6 2 COUT7, COUT9 CAP, 0805, 10μF, 10%, 6.3V, X5R NIC NMC0805X5R106K6.3TRPLP3KF 7 1 CTR1 CAP, 0402, 4700pF, 10%, 50V, X7R TDK C1005X7R1H472K 8 0 CTTR1 CAP, 0603, 10nF, 10%, 16V, X7R AVX 0603YC103KAT2A OPTION 9 1 CVCC1 CAP, 0603, 1μF, 10%, 16V, X5R NIC NMC0603X5R105K16TRPF 10 0 RD1, RTR2, RD2, R6, RFREQ, RDDQIN OPTION RES, 0402 OPTION 11 2 RPG1, RPG2 RES, 0402, 100kΩ, 5%, 1/16W NIC NRC04J104TRF 12 1 RTR1 RES, 0402, 0Ω, JUMPER NIC NRC04Z0TRF 13 2 R1, R2 RES, 0402, 1MΩ, 5%, 1/16W NIC NRC04J105TRF 14 1 R4 RES, 0402, 17.4kΩ, 1%, 1/16W NIC NRC04F1742TRF 15 1 R5 RES, 0402, 23.2kΩ, 1%, 1/16W NIC NRC04F2322TRF 16 1 R7 RES, 0402, 1kΩ, 1%, 1/16W NIC NRC04F1001TRF Hardware/Components (For Demo Board Only) 1 17 E1-E17 TURRET MILL-MAX 2501-2-00-80-00-00-07-0 2 4 JP1, JP2, JP4, JP5 HEADER, 3-PIN, 2mm SAMTEC TMM-103-02-L-S 3 1 JP3 HEADER, 3-PIN, DBL ROW 2mm SAMTEC TMM 103-02-L-D 4 1 JP6 HEADER, 4-PIN, DBL ROW 2mm SAMTEC TMM 104-02-L-D 5 6 JP1-JP6 SHUNT, 2mm SAMTEC 2SN-BK-G dc1839af 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 [1] E6 E9 E15 E12 E10 E1 E2 [1] 0 RTR2 OPT RTR1 R7 1k 1% JP2 3 2 1 VIN 3 90° SS CTR1 4700pF OFF ON CC1 10pF OPT JP1 RUN1 3 2 1 5 4 R1 1M OPT RD2 RPG1 100K INTVCC 1 ITH1 2 TRACKSS1 5 PHMODE 7 MODE/SYNC 22 INTVCC 6 RUN1 9 RUN2 RITH2 15k 1% OPT RT 324k 1% RFREQ CITH2 1000pF INTVCC CITH1 CC2 680pF 10pF OPT RITH1 18.2k 1% CVCC 1uF 0603 VIN [1] CIN5 AND CIN6 ARE INSERTED ON THE DC1839A TO DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO THE USE OF LONG INPUT LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, CIN5 AND CIN6 ARE NOT NEEDED. 2. ALL RESISTOR AND CAPACITOR CASE SIZE ARE 0402. JP5 3 TRACKSS 1 TRACK 2 2 1 180° JP4 6 4 2 INTVCC JP3 MODE 1M R2 CIN2 47uF 16V 1210 PHASE 5 BURST MODE 1 SYNC 3 OFF ON RUN2 CIN4 47uF 16V 1210 OPT (FORCED FCM CONTINUOUS MODE) INTVCC CIN6 22uF 35V 7343 CVCC1 1uF 0603 + NOTES: UNLESS OTHERWISE SPECIFIED TRACK1 GND GND SYNC INTVCC PGOOD1 VIN1 3.6V - 15V CIN1 47uF 16V 1210 VIN U1 LTC3634EFE L1 1.0uH L2 0.47uH 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 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. JW TOM G. 2 SCALE = NONE APP ENG. PCB DES. APPROVALS 2.5V R3 11k 1% JP6 RVDDQ 0 RFB1 34.8k 1% VISHAY IHLP-2020BZERR47M01 CBST2 0.1uF VISHAY IHLP-2020BZER1R0M01 CBST1 0.1uF CUSTOMER NOTICE CTTR 10nF 0603 VON2 15 VFB2 12 17 SW2 16 SW2 BOOST2 20 VON1 28 VFB1 3 SW1 27 SW1 26 BOOST1 23 VDDQIN 13 RPG2 100K INTVCC 14 CIN3 47uF 16V OPT 1210 ITH2 CIN5 22uF 35V 7343 RT 8 + PGOOD1 4 SGND 10 E17 VIN1 25 VIN1 24 VIN2 19 VIN2 18 PGND 29 VIN2 PGOOD2 11 VTTR 21 2 OPT RD1 10pF CFFW1 DATE: N/A SIZE COUT3 100uF 6.3V 1812 COUT4 100uF 6.3V 1812 IC NO. 1 CTTR1 10nF 0603 OPT COUT9 10uF 6.3V 0805 E3 E16 E13 E5 E7 E14 COUT7 E4 10uF 6.3V 0805 E11 E8 TOM G. DATE 06-08-11 GND GND VTTR 10mA VTT 3A GND GND VDDQ 3A VDDQIN PGOOD2 APPROVED Thursday, June 30, 2011 1 LTC3634EFE DEMO CIRCUIT 1839A SHEET 1 1 REV. OF 1 DUAL DDR 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 COUT8 100uF 6.3V 1812 OPT COUT5 100uF 6.3V 1812 OPT PRODUCTION CDDQIN 10uF 0805 OPT REVISION HISTORY DESCRIPTION TECHNOLOGY COUT6 100uF 6.3V 1812 1.5V USER SELECT R6 R5 23.2k OPT 1% VDDQ SEL INTVCC TITLE: SCHEMATIC COUT2 100uF 6.3V 1812 1.8V R4 17.4k 1% OPT RDDQIN 1 REV COUT1 100uF 6.3V 1812 __ ECO 2 1 3 4 3 VIN 6 5 4 8 7 5 A B C D DEMO MANUAL DC1839A SCHEMATIC DIAGRAM dc1839af 7 DEMO MANUAL DC1839A 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 dc1839af 8 Linear Technology Corporation LT 0711 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2011
DC1839A
物料型号:LTC3634EFE 器件简介:LTC3634是一款高电压双通道同步降压型稳压器,适用于DDR内存电源应用。

引脚分配:LTC3634EFE采用28引脚QFN或有铅封装,底部有暴露的垫片以改善热性能。

参数特性:输入电压范围3.6V至15V,输出电压VDDQ有1.5V、1.8V和2.5V三档固定设置,可提供高达3A的输出电流。

第二通道VTT可提供或吸收最大3A的电流。

功能详解:DC1839A演示板基于LTC3634,具有500kHz至4MHz的可编程工作频率,支持Burst Mode®操作或强制连续模式,提供高效率和高负载电流。

应用信息:DC1839A适用于DDR内存电源应用,提供高效率和稳定的电源解决方案。

封装信息:LTC3634EFE采用28引脚QFN或有铅封装,底部有暴露的垫片以改善热性能。
DC1839A 价格&库存

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