1
dc1872af
DEMO MANUAL DC1872A
DESCRIPTION
LTM4637
20A DC/DC µModule
Step-Down Regulator
Demonstration circuit
DC1872A
features the
LTM
®
4637EV
,
a high efficiency, high density switch mode step-down
power µModule
®
regulator. The input voltage range is
from 4.5V to 20V. The output voltage is jumper pro-
grammable from 1.0V to 1.8V with a rated load current
of 20A. Derating is necessary for certain V
IN
, V
OUT
, fre-
quency and thermal conditions. The DC1872A offers the
TRACK/SS pin, allowing the user to program output track-
ing or soft-start period. The DC1872A allows the user to
L
, LT, LTC, LTM, Linear Technology, the Linear logo, µModule and Burst Mode are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
PERFORMANCE SUMMARY
BOARD PHOTO
choose pulse-skipping mode or Burst Mode
®
operation
for higher efficiency at light load conditions.
The LTM4637 data sheet must be read in conjunction with
this demo manual prior to working on or modifying demo
circuit DC1872A.
Design files for this circuit board are available at
http://www.linear.com/demo
PARAMETER
CONDITIONS / NOTES
VALUE
Input Voltage Range
4.5V to 20V
Output Voltage V
OUT
Jumper Selectable
1.0V, 1.2V, 1.5V, 1.8V ±1.5%
Maximum Continuous Output Current
Derating Is Necessary for Certain Operating
Conditions. See Data Sheet for Details
20ADC
Operating Frequency
R
fSET
=124kΩ
520kHz
Efficiency
V
IN
= 12V, V
OUT
= 1.0V, I
OUT
= 20A
82.2% See Figure 2
Load Transient
V
IN
= 12V, V
OUT
= 1.0V
See Figure 3