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dc2681aaf

DEMO MANUAL DC2681A-A

DESCRIPTION

LTM4645 

25A DC/DC Step-Down 

µModule Regulator 

Demonstration circuit DC2681A-A features the 

LTM

®

4645EY, a 25A high efficiency, switch mode step-

down power µModule

®

 regulator. The input voltage 

range is from 6V to 15V. To use DC2681A-A for input 

voltage range from 4.7V to 6V, connect INTV

CC

 to SV

IN

 

(change R22 from OPT to 0Ω), DRV

CC

 to V

IN

 (change 

R21 from 0Ω to OPT, R28 from OPT to 0Ω). The output 

voltage range is 0.6V to 1.8V. Derating is necessary for 

certain V

IN

, V

OUT

, frequency and thermal conditions. The 

DC2681A-A offers the TRK/SS pin allowing the user to 

program output tracking or soft-start period. The board 

operates in continuous conduction mode in heavy load 

conditions. For high efficiency at low load currents, the 

MODE_PLLIN jumper selects pulse-skipping mode for 

noise sensitive applications or burst mode operation in 

L

, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of 

Analog Devices, Inc. All other trademarks are the property of their respective owners.

BOARD PHOTO

less noise sensitive applications. The MODE_PLLIN pin 

also allows the 

LTM4645

 to synchronize to an external 

clock signal (between 400kHz and 800kHz). DC2681A-A 

has the option of choosing both internal and external 

compensation circuit for LTM4645. Tying the PHASMD 

pin to different voltage generates certain phase differ-

ence between MODE_PLLIN and CLKOUT. The LTM4645 

data sheet must be read in conjunction with this demo 

manual prior to working on or modifying demo circuit 

DC2681A-A.

Design files for this circuit board are available at  

http://www.linear.com/demo/DC2681A-A

Содержание Linear DC2681A-A

Страница 1: ...itions For high efficiency at low load currents the MODE_PLLIN jumper selects pulse skipping mode for noise sensitive applications or burst mode operation in L LT LTC LTM µModule Linear Technology and the Linear logo are registered trademarks of Analog Devices Inc All other trademarks are the property of their respective owners BOARD PHOTO less noise sensitive applications The MODE_PLLIN pin also ...

Страница 2: ...ge efficiency and other param eters 5 Optional For optional load transient test apply an adjustable pulse signal between IOSTEP_CLK and GND test points The pulse amplitude sets the load step cur rent amplitude Keep the pulse width short 1ms and pulse duty cycle low 5 to limit the thermal stress on the load transient circuit 6 Optional LTM4645 can be synchronized to an external clock signal Place t...

Страница 3: ...3 dc2681aaf DEMO MANUAL DC2681A A QUICK START PROCEDURE Figure 1 Measurement Setup of DC2681A A LOAD VIN dc2681aaf F01 ...

Страница 4: ...86 00 88 00 90 00 EFFICIENCY 0 00 5 00 10 00 15 00 20 00 25 00 OUTPUT CURRENT A 1 8 VOUT 1 5 VOUT 1 2 VOUT 1 0 VOUT 0 8 VOUT dc2681aaf F02 VOUT 50mV DIV IOUT_STEP 10A DIV dc2681aaf F03 Figure 2 Measured Efficiency at VIN 12 0V fSW 600kHz CCM Figure 3 Measured Load Transient 12VIN 600kHz Efficiency Sweeps ...

Страница 5: ...5 dc2681aaf DEMO MANUAL DC2681A A QUICK START PROCEDURE Figure 4 Thermal Image of LTM4645 VIN 12V VOUT 1 0V ILOAD 25A Ambient Temperature 25 0 C No Forced Air Flow ...

Страница 6: ...9k 1 10W 1 0603 VISHAY CRCW060390K9FKEA 16 1 R20 RES SENSE 0 01Ω 1 2W 1 2010 VISHAY WSL2010R0100FEA 17 1 R25 RES 2 2Ω 1 10W 5 0603 VISHAY CRCW06032R2JNEA 18 1 R26 RES 50k 1 10W 1 0603 VISHAY CRCW060350K0FKEA 19 1 U1 IC LTM4645EY PBF BGA77 15 9 5 01 LINEAR TECH LTM4645EY PBF Additional Demo Board Circuit Components 1 0 CIN2 CAP OPTION 1206 MURATA GRM31CR6YA106KA12L 2 0 CIN5 COUT3 COUT5 COUT6 COUT9 ...

Страница 7: ...ERING FOR ASSISTANCE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SCHEMATIC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 1 Monday February 27 2017 1 1 SINGLE OUTPUT HIGH EFFICIENCY STEP DOWN LT YL B LTM4645EY LTM4647EY DEMO CIRCUIT 2681A A B SIZE DATE IC NO REV SHEET OF TITLE APPROVALS PCB DES APP ENG TECHNOLOGY Fax 408 434 0507 Milpitas CA 95035 Phone 408 432 19...

Страница 8: ... 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 i...

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