LTM4627EV
2
QUICK START PROCEDURE
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 follow-
ing positions for a typical 1.8V
out
application:
JP1
JP2 JP3
JP4
TRACK/SS RUN MODE V
OUT
Select
SOFTSTART ON CCM 1.8V
2. Before connecting input supply, load and me-
ters, pre-set the input voltage supply to be less
than 20V. 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 volt-
age ± 2%.
5. Once the proper output voltage is established,
adjust the load current within the 0-15A range
and observe the load regulation, efficiency,
and other parameters. Output voltage ripple
should be measured at J4 with a BNC cable
and oscilloscope.
6. To observe increased light load efficiency
place the Mode pin jumper (JP3) in the Burst
Mode position. To observe increased light load
efficiency with a reduced output ripple as com-
pared to Burst Mode
®
place the Mode pin
jumper in the Pulse skip position.
7. For optional load transient testing apply an ad-
justable positive pulse signal between IOSTEP
CLK and GND pins. The pulse amplitude sets
the load step current amplitude. The pulse
width should be short (< 1us) and pulse duty
cycle should be low (< 15%) to limit the ther-
mal 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 in-
put supply power, apply the following changes
listed below.
R7 R6 R12 JP4
Remove 0 ohm 8.25k (1%) 1V
