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dc1780abfa

DEMO MANUAL DC1780A-B

 DESCRIPTION

LTM4620EV: High Efficiency, 

PolyPhase 75A Step-Down 

Power µModule

®

 Regulator  

Demonstration circuit 1780A-B features PolyPhase

®

 

design using the LTM

®

4620EV, the high efficiency, high 

density, dual 13A, switch mode step-down power module 
regulator. The input voltage is from 4.5V to 16V. The 
output voltage is jumper selectable from 1.0V to 2.5V. 
DC1780A-B can deliver nominal 75A output current with 
3× LTM4620s in parallel. As explained in the data sheet, 
output current derating is necessary for certain V

IN

, V

OUT

and thermal conditions. The LTM4620 on DC1780A-B 
always operates in continuous conduction mode. The 
switching frequency can be programmed through a resistor 
or can be synchronized to an external clock signal. The 
board allows the user to program how its output voltage 
ramps up and down through the TRACK_CONTROL pin. 

The output voltage is tightly regulated between V

OUT

+

 

and V

OUT

 through remote output voltage sensing which 

improves output voltage regulation at heavy loads. These 
features and the availability of the LTM4620EV in a compact 
15mm × 15mm × 4.41mm LGA package make it ideal for 
use in many high density point-of-load regulation applica-
tions. The LTM4620 data sheet must be read in conjunction 
with this demo manual prior to working on or modifying 
the demo circuit DC1780A-B. 

Design files for this circuit board are available at 

http://www.linear.com/demo

L

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

trademarks of Linear Technology Corporation. All other trademarks are the property of their 
respective owners.

Figure 1. 75A PolyPhase LTM4620/DC1780A-B Demo Board

 BOARD PHOTO

Summary of Contents for DC1498A

Page 1: ...to an external clock signal The board allows the user to program how its output voltage ramps up and down through the TRACK_CONTROL pin The output voltage is tightly regulated between VOUT and VOUT through remote output voltage sensing which improves output voltage regulation at heavy loads These featuresandtheavailabilityoftheLTM4620EVinacompact 15mm 15mm 4 41mm LGA package make it ideal for use ...

Page 2: ...OSTEP CLK and GND testpoint Thepulseamplitude 3Vto3 5V setstheload stepcurrentamplitude Theoutputtransientcurrentcan be monitored at the BNC connector J8 5mV A The pulse signal should be very small duty cycle 10 to limit the thermal stress on the transient load circuit 6 Optional LTM4620canbesynchronizedtoanexternal clock signal Place the JP1 jumper on EXT_CLK and apply a clock signal 0V to 5V squ...

Page 3: ...n track another supply The output voltage tracks the voltage on TRACK_CONTROL when a valid signal is applied on the test point 8 Optional DC1780A B can be configured to a dual outputs configuration with VOUT at 62A load current and VOUT2 at 13A load current Stuff 0Ω resistor on R61 and 0 1μF on C14 Remove R22 R23 R24 R26 R27 R28 R32 R33 R35 Output voltage VOUT2 is set by R37 based on the equation ...

Page 4: ...th Standard Demo Circuit Default Setup LOAD CURRENT A 0 EFFICIENCY 100 90 80 70 60 40 10 DC1780A B F03 50 60 70 30 20 VIN 5V VOUT 2 5V VIN 5V VOUT 1 8V VIN 5V VOUT 1 5V VIN 5V VOUT 1 2V VIN 5V VOUT 1V LOAD CURRENT A 0 EFFICIENCY 100 90 80 70 60 40 10 DC1780A B F04 50 60 70 30 20 VIN 12V VOUT 2 5V VIN 12V VOUT 1 8V VIN 12V VOUT 1 5V VIN 12V VOUT 1 2V VIN 12V VOUT 1V DC1780A B F05 1V OUTPUT 20MHz BW...

Page 5: ...B Figure 7 Thermal Capture at 12VIN 1 0VOUT at 75A Ambient Temperature 23 3 C No Airflow and No Heat Sink Figure 8 Thermal Capture at 12VIN 1 0VOUT at 75A Ambient Temperature 23 3 C 200LFM Airflow and No Heat Sink QUICK START PROCEDURE ...

Page 6: ...NEA 14 1 C22 Cap X5R 2 2μF 10V 20 0603 Taiyo Yuden LMK107BJ225MA 15 1 C25 Cap X7R 0 1μF 25V 10 0603 AVX 06033C104KAT2A 16 1 CIN1 Cap Alum 150μF 25V 25 SUNCON 8 SUNCON 25CE150AX 17 2 CIN2 CIN11 Cap X5R 1μF 25V 10 1210 Taiyo Yuden TMK325BJ105KM 18 0 COUT2 COUT3 COUT8 COUT9 COUT13 COUT14 COUT16 CIN16 COUT17 CIN17 CIN18 CIN19 COUT21 COUT22 COUT27 COUT28 COUT30 COUT32 COUT33 COUT34 COUT35 COUT36 OPT Ca...

Page 7: ...11 E1 E2 E3 E4 E6 E7 E8 E9 E12 E13 E22 Turret Testpoint Mill Max 2308 2 00 80 00 00 07 0 38 0 E5 E10 E11 E14 E15 E16 E17 E18 Opt Testpoint 39 2 E19 E20 Turret Testpoint Mill Max 2501 2 00 80 00 00 07 0 40 2 JP1 JP2 Headers 3 Pins 2mm Ctrs Samtec TMM 103 02 L S 41 5 JP4 JP5 JP6 JP7 JP8 Jumper 2 Pins 2mm Ctrs Samtec TMM 102 02 L S 42 6 J1 J2 J3 J4 J5 J6 Stud Test Pin PEM KFH 032 10 43 12 NUT BRASS N...

Page 8: ...IC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 1 02 5 8 7 0RQGD HFHPEHU 1 4 1 32 3 6 1 70 9 5 JEFF Z 67 3 2 1 32 5 02 8 5 8 725 ͰW WZK d ͰϭϳϴϬ Ͱ ͰϭϳϴϬ Ͳ ͰϭϳϴϬ Ͳ ͺϬϬͺZ sϭ E COUT7 100uF 10V 1210 COUT7 100uF 10V 1210 E9 TRACK_CONTROL E9 TRACK_CONTROL R16 40 2K 1 R16 40 2K 1 E8 EXTVCC E8 EXTVCC JP8 2 5V JP8 2 5V CIN5 22uF 25V 1210 CIN5 22uF 25V 1210 JP2 ON OFF RUN JP2 ON OF...

Page 9: ...ING FOR ASSISTANCE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SCHEMATIC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 1 02 5 8 7 0RQGD HFHPEHU 2 4 1 32 3 6 1 70 9 5 JEFF Z 67 3 2 1 32 5 02 8 5 8 725 ͰW WZK d ͰϭϳϴϬ Ͱ ͰϭϳϴϬ Ͳ ͰϭϳϴϬ Ͳ ͺϬϬͺZ sϭ E R29 10 R29 10 C11 1uF 10V C11 1uF 10V R23 0 Ohm 2010 R23 0 Ohm 2010 R38 OPT R38 OPT R19 0 Ohm R19 0 Ohm C8 OPT C8 OPT U2 ...

Page 10: ...CTUAL APPLICATION COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SCHEMATIC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 1 02 5 8 7 0RQGD HFHPEHU 3 4 1 32 3 6 1 70 9 5 JEFF Z 67 3 2 1 32...

Page 11: ...LICATION COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SCHEMATIC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 1 02 5 8 7 0RQGD HFHPEHU 4 4 1 32 3 6 1 70 9 5 JEFF Z 67 3 2 1 32 5 02 8 5...

Page 12: ... 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 th...

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