2
dc1669af
DEMO MANUAL DC1669A
QUICK START PROCEDURE
Figure 1. Test Setup of DC1669A
Demonstration circuit 1669 is easy to set up to evaluate the
performance of the LTM4627EV. Please refer to Figure 1
for test setup connections and follow the procedure below.
1. With power off, place the jumpers in the following
positions for a typical 1.8Vout application:
JP1
JP2
JP3
JP4
TRACK/SS
RUN
MODE
V
OUT
Select
SOFTSTART
ON
CCM
1.8V
2. Before connecting input supply, load and meters, preset
the input voltage supply to be less than 20V. Preset 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 15A range and observe
the load regulation, effi ciency and other parameters.
Output voltage ripple should be measured at J4 with a
BNC cable and oscilloscope.
6. To observe increased light load effi ciency place the
Mode pin jumper (JP3) in the Burst Mode position. To
observe increased light load effi ciency with a reduced
output ripple as compared to Burst Mode operation place
the MODE pin jumper in the pulse-skipping position.
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 (<1μs)
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 J3 (15mV/A).
Note:
To set the output voltage to 5V turn off the input supply
power, apply the following changes listed below.
R7
R6
R12
JP4
Remove
0Ω
8.25k (1%)
1V
A
+
–
A
–
+
+
–
V
IN
V
+
–
V
+
–
–
+
LOAD
0A TO
15A
