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dc2455aaf

DEMO MANUAL DC2455A-A

Quick start proceDure

Demonstration circuit DC2455A-A is easy to set up to 

evaluate the performance of PolyPhase operation of the 

LTM4650EY-1. Due to the high input/output current, user 

should select the proper input supply/load/cable which 

can sustain the full load operation. It’s recommended to 

pull load current from J2 and J4. The load current pulled 

from  J5 and J6 shouldn’t exceed 25A. Please refer to 

Figure 2 for proper measurement setup and follow the 

procedure below:  
1. Place jumpers in the following positions for a typical 

1.0V

OUT

 application: 

JP1

JP2

JP4~JP8

CLK

RUN

V

OUT

 SELECT

INT

OFF

ON JP5 / 1.0V

2. With power off, connect the input power supply, load 

and meters as shown in Figure 2. Preset the load to 0A 

and V

IN

 supply to 12V. 

3. Turn on the power supply at the input. Place JP2 to ON 

position. The output voltage between “V

O

+

” and “V

O

” 

should be 1.0V ± 1.5% (0.985V~1.015V). 

4.  Once the proper output voltage is established, adjust the 

load within the operating range and observe the output 

voltage regulation, output voltage ripple, efficiency 

and other parameters. Output voltage ripple should be 

measured at J11 with BNC cables. 50Ω termination 

should be set on the oscilloscope or BNC cables. 

5. (Optional) For optional load transient test, apply an ad-

justable pulse signal between “IOSTEP CLK” and “GND” 

test point. Pulse amplitude (3V~3.5V) sets the load step 

current amplitude. The output transient current can be 

monitored at the BNC connector J12 (5mV/A). The pulse 

signal should be very small duty cycle (< 10%) to limit 

the thermal stress on the transient load circuit.

6. (Optional)  LTM4650-1 can be synchronized to an 

external clock signal. Place the JP1 jumper on EXT 

and apply a clock signal (0V~5V, square wave) on the 

“EXT_CLK” test point.

7.  (Optional) The outputs of LTM4650-1 can track another 

supply. The output voltage tracks the voltage on TRACK 

when a valid signal is applied on the test point. 

8. (Optional)  DC2455A-A can be configured to a dual 

outputs configuration with V

O

 at 75A load current and 

V

O2

 at 25A load current. Stuff 0Ω resistor on R61 and 

0.1µF on C14. Remove R22, R23, R24, R26, R27, R28, 

R32, R33, R35. Output voltage V

O2

 is set by R37 based 

on the equation V

O2

 = 0.6V(1 + 60.4k/R37). 

performance summary

Specifications are at T

A

 = 25°C

PARAMETER

CONDITIONS / NOTES

VALUE

Input Voltage Range

4.5V ~ 15V

Output Voltage V

OUT

V

IN

 = 4.5V to 15V, I

OUT

 = 0A to 100A, JP5: 1.0V

1.0V ± 1.5% (0.985V ~ 1.015V)

Maximum Continuous Output Current 

De-rating is necessary for certain V

IN

, V

OUT

 and thermal 

conditions, see data sheet for detail.

100A 

Default Operating Frequency

500kHz

Resistor Programmable Frequency Range

400kHz – 780kHz

External Clock Sync. Frequency Range

400kHz – 780kHz

Efficiency 

V

IN

 = 12V, V

OUT

 = 1.0V, I

OUT

 = 100A, f

SW

 = 500kHz

86.5% See Figure 3 

Load Transient 

V

IN

 = 12V, V

OUT

 = 1.0V, I

STEP

 = 50A to 75A 

< 57mV, See Figure 4

Summary of Contents for LTM4650EY-1

Page 1: ...ternalclocksignal Theboardallowstheusertoprogram how its output voltage ramps up and down through the L LT LTC LTM Linear Technology the Linear logo Module PolyPhase and TimerBlox are registered trade...

Page 2: ...esignalbetween IOSTEPCLK and GND testpoint Pulseamplitude 3V 3 5V setstheloadstep current amplitude The output transient current can be monitoredattheBNCconnectorJ12 5mV A Thepulse signal should be ve...

Page 3: ...tart Procedure 1m VOUT0 LOAD 0A 100A VIN 4 5V TO 16V Figure 2 Test Setup of DC2455A A Figure 3 Measured Efficiency VIN 12V fSW 500kHz LOAD CURRENT A 0 EFFICIENCY 100 95 75 90 85 80 70 40 20 60 DC2455A...

Page 4: ...0mV DIV AC COUPLED 50A TO 75A LOAD X AXIS DC2455AA F05 VOUT 20MHz BW 5mV DIV Figure 4 Load Transient 50A to 75A VIN 12V VOUT1 1V fSW 500kHz Figure 5 Output Voltage Ripple VIN 12V VOUT1 1V IOUT 100A fS...

Page 5: ...03 47nF 10 50V X7R AVX 06035C473KAZ2A 17 1 L1 IND 68 uH CDRH105 SUMIDA CDRH105RNP 680N 18 2 Q1 Q2 MOSFET N CH D S 40V TO252 VISHAY SUD50N04 8M8P 4GE3 19 4 R1 R3 R25 R29 RES 0603 10 5 1 10W VISHAY CRCW...

Page 6: ...OPTION 7 13 R6 R19 R20 R27 R28 R32 R33 R35 R40 R45 R62 R63 R91 RES 0603 0 JUMPER VISHAY CRCW06030000Z0EA 8 4 R22 R23 R24 R26 RES 2010 0 JUMPER VISHAY CRCW20100000ZEA9 9 1 R60 RES 1206 0 JUMPER VISHAY...

Page 7: ...CATIONS 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 AFF...

Page 8: ...GY 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 APPLICA...

Page 9: ...McCarthy Blvd LTC CONFIDENTIAL FOR CUSTOMER USE ONLY CUSTOMER NOTICE LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER SUPPLIED SPECIFICATIONS HOWEVER IT REMAINS THE CU...

Page 10: ...ENTIAL FOR CUSTOMER USE ONLY CUSTOMER NOTICE LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER SUPPLIED SPECIFICATIONS HOWEVER IT REMAINS THE CUSTOMER S RESPONSIBILITY T...

Page 11: ...ACTUAL APPLICATION COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANC...

Page 12: ...TORY 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 INCIDENT...

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