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dc1872af
DEMO MANUAL DC1872A
QUICK START PROCEDURE
Demonstration circuit DC1872A is an easy way to eva-
luate the performance of the LTM4637EV. Please refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below:
1. Place jumpers in the following positions for a typical
1.0V
OUT
application:
RUN
MODE
TRACK/SS
VOUT SELECT
ON
CCM
SS
1.0V
2. With power off, connect the input power supply, load
and meters as shown in Figure 1. Preset the load to
0A and V
IN
supply to be 0V.
3. Turn on the power at the input. Increase V
IN
to 12V (Do
not apply more than the rated maximum voltage of
20V to the board or the part may be damaged). The
output voltage should be regulated and deliver the
selected output voltage ±1.5%.
4. Vary the input voltage from 4.5V to 20V and adjust
the load current from 0A to 20A. Observe the output
voltage regulation, ripple voltage, efficiency, and other
parameters. Output voltage ripple may be measured at
J4 with a BNC cable and oscilloscope. The probe channel
for V
OUT
should be set at 50Ω termination resistance
to match the BNC cable.
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. The load step current can
be monitored with a BNC connected to J3 (15mV/A).
V
+
–
A
–
+
A
–
+
LOAD
+
–
+
–
V
+
–
DC1872A F01
V
IN
Figure 1. Proper Measurement Equipment Setup