LTC3111EDHD datasheet(2/6 Pages) LINER

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dc1999af

DEMO MANUAL DC1999A

QUICK START PROCEDURE

Using short twisted-pair leads for any power connections

and with all loads and power supplies off, refer to Figure 1

for the proper measurement and equipment setup. The

power supply should not be connected to the circuit until

told to do so in the procedure below.

When measuring the input or output voltage ripple, care

must be taken to avoid a long ground lead on the oscil-

loscope probe.

1. JP1, JP2 and Load Settings to start:

JP1 (RUN) = OFF

JP2 (PWM) = 800kHz (Fixed Frequency)

LOAD = 0.1A/50Ω 10W Resistor

2. With power OFF connect the power supply as shown in

Figure 1. If accurate current measurements are desired

(for efficiency calculations for example) then connect

an ammeter in series with the supply as shown. The

ammeter is not required however.

3. Connect the load to VOUT as shown in Figure 1. Again,

connect an ammeter if accurate current measurement

or monitoring is desired.

4. Turn on the power supply and slowly increase voltage

until the voltage at VIN is 2.5V. Move Jumper JP1 to

ON.

5. Verify VOUT is ~5.0V.

6. VIN can now be varied between 2.5V and 15.0V. VOUT

should remain in regulation.

7. IOUT can also be varied from 0A to 1.5A. For VIN < 5.0V,

maximum IOUT is reduced. This reduction is due to IIN

increasing as VIN decreases. Once the input current

limit is reached, VOUT will fall out of regulation.

Note: If VOUT drops out of regulation, check to be sure

the maximum load has not been exceeded, or that VIN is

not below the minimum value (2.5V).

Figure 1. Measurement Setup

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