Linear Technology LTM4649EY, Demo Manual

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dc1856a-bf
DEMO MANUAL DC1856A-B
QUICK START PROCEDURE
Figure 1. Test Setup of DC1856A-B
Demonstration circuit 1856A-B is an easy way to evaluate
the performance of the LTM4649EY. 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 1.8V
OUT
application:
JP8 JP7 JP9 JP2
TRACK/SS RUN MODE V
OUT
Select
SS ON CCM 1.8V
2. Before connecting input supply, load and meters, preset
the input voltage supply to be between 4.5V to 16V.
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 10A range and observe
the load regulation, efficiency, and other parameters.
Output voltage ripple should be measured at J6 with a
BNC cable and oscilloscope.
6. To observe increased light load efficiency place the
Mode pin jumper (JP9) in the Burst Mode
®
position. To
observe increased light load efficiency 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 (<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 (10mV/A).
Note: To evaluate PGOOD pin operation for the LTM4649,
insert a 100k resistor between PGOOD and INTVCC. Do
not stuff R15.
V
+
–
A
–
+
A
– +
LOAD
0A TO 10A
V
IN
+ –
V
+
–
+
–