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dc1889af
DEMO MANUAL DC1889A
Quick start proceDure
Demonstration circuit 1889A is an easy way to evaluate the
performance of the LTM4624EY. Please refer to Figure 1
for test setup connections and follow the procedure below.
1. With power off, place the jumpers in the follow-ing
positions for a typical 1.8Vout application:
JP7
JP6
JP4
RUN
MODE
VOUT Select
ON
CCM
1.8V
2. Before connecting input supply, load and meters, pre-
set the input voltage supply to be between 4V to 14V.
Pre-set the load current to 0A.
3. With power off, connect the load, input voltage supply
and meters as shown in Figure 1.
4. Turn on input power supply. The output voltage meter
should display the selected output voltage ±2%.
5. Once the proper output voltage is established, adjust
the load current within the 0A to 4A range and observe
the load regulation, efficiency, and other parameters.
Output voltage ripple should be measured at J6 with a
BNC cable terminated into 50Ω and an oscilloscope.
6. To observe increased light load efficiency place the
MODE pin jumper (JP6) in the DCM position while input
power is removed.
7. For optional load transient testing apply an adjustable
positive pulse signal between IOSTEP CLK and GND
pins. The pulse amplitude sets the load step current
amplitude. The pulse width should be short (<1ms)
and pulse duty cycle should be low (<15%) to limit the
thermal stress on the load transient circuit. The load
step current can be monitored with a BNC connected
to J5 (50mV/A).
+
–
A
–
+
A
–
+
LOAD
0A TO 4A
+
–
V
+
–
V
+
–
V
IN
Figure 1. Test Setup
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