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dc2681aaf
DEMO MANUAL DC2681A-A
QUICK START PROCEDURE
Demonstration circuit DC2681A-A is an easy way to evalu-
ate the performance of the LTM4645EY. 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
application:
MODE
RUN
CCM
ON
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 12V.
3. Turn on the power supply at the input. The output volt-
age should be 1.0V ± 1.0% (0.99V to 1.01V).
4. Vary the input voltage from 6V to 15V and adjust the
load current from 0A-25A. Observe the output voltage
regulation, ripple voltage, efficiency, and other param-
eters.
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.
6. (Optional) LTM4645 can be synchronized to an external
clock signal. Place the JP1 jumper on EXT_CLK and
apply a clock signal (0V to 5V, square wave) on the
MODE_PLLIN test point.
PERFORMANCE SUMMARY
PARAMETER
CONDITIONS/NOTES
VALUE
Input Voltage Range
6V to 15V
Output Voltages
1.0V ± 1.0%
Maximum Continuous Output Current
Derating is Necessary for Certain Operating
Conditions. See Data Sheet for Details
25ADC
Operating Frequency
600kHz
Efficiency
V
IN
= 12V, V
OUT
= 1.0V, I
OUT
= 25A
84.6% Figure 2
Load Transient V
OUT(P-P)
V
IN
= 12V, V
OUT
= 1.0V, I
STEP
= 0A to 12.5A
128mV Figure 3
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