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dc1889af

DEMO MANUAL DC1889A

Quick start proceDure

Demonstrationcircuit1889Aisaneasywayto evaluatethe

performance of the LTM4624EY. Please refer to Figure 1

fortestsetupconnectionsandfollowtheprocedurebelow.

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

+

–

Figure 1. Test Setup