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dc2251af
DEMO MANUAL DC2251A
Description
LTM8065
40V, 2.5A Silent Switcher
µModule Regulator
Demonstration circuit 2251A is a 40V, 3.5A peak, 2.5A
continuous step-down μModule
®
regulator featuring the
LTM
®
8065
. The demo board is designed for 5V output
from a 6V to 40V input. The wide input range allows a
variety of input sources, such as automotive batteries and
industrial supplies. The user adjustable features of the
LTM8065 such as output voltage, switching frequency,
soft-start and power good can be changed on DC2251A
simply by modifying the appropriate resistors and/or
capacitors.
The LTM8065 can be programmed to different operation
modes. The SYNC pin on the demo board is grounded
(JP1 at BURST position) by default for low ripple Burst
Mode
®
operation. Pulse-skipping mode, spread spectrum
mode or synchronization mode can be selected respec-
tively by moving JP1 shunt to SYNC position and adding
different signals to SYNC terminal. See Quick Start Pro-
cedure section for more details.
L
, LT, LTC, LTM, Linear Technology, Burst Mode, µModule and the Linear logo are registered
trademarks of Analog Devices, Inc. All other trademarks are the property of their respective
owners.
BoarD photo
Figure 1 shows the efficiency of the circuit under differ-
ent input voltages in Burst Mode operation. The rated
maximum continuous load current is 2.5A, while derating
is necessary for certain input voltage and thermal condi-
tions. Figure 2 shows the LTM8065 derating curve on
DC2251A demo board. The demo board has an optional
EMI filter. To achieve high EMI/EMC performance, the
input EMI filter is required and the input voltage should
be applied at VIN_EMI terminal.
The LTM8065 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this demo manual
for demo circuit 2251A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2251A
