LTC3111EDHD Datasheet, PDF (2/6 Pages) Linear Technology – 15V, 1.5A Synchronous Buck-Boost DC/DC Converter

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. V_IN can now be varied between 2.5V and 15.0V. V_OUT
should remain in regulation.
7. I_OUT can also be varied from 0A to 1.5A. For V_IN < 5.0V,
maximum I_OUT is reduced. This reduction is due to I_IN
increasing as V_IN decreases. Once the input current
limit is reached, V_OUT will fall out of regulation.
Note: If V_OUT drops out of regulation, check to be sure
the maximum load has not been exceeded, or that V_IN is
not below the minimum value (2.5V).
Figure 1. Measurement Setup
dc1999af
2