QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1062
DUAL BUCK-BOOST + BUCK SYNCHRONOUS CONVERTERS
1
LTC3520
DESCRIPTION
Demonstration circuit 1062 is a micropower synchro-
nous buck-boost + buck converter based on the
LTC3520. The DC1062 has an input voltage range of
2.2 V to 5.5V and three output voltages: 3.3V @ up to
1A, 1.8V @ 600mA and 1.5V @ 200mA. The 1.5Vout is
an LDO regulator derived from either the 3.3Vout or
the 1.8Vout. The Buck-Boost + Buck converters can
operate in either low-power burst mode or low-noise
fixed-frequency PWM mode. The switching frequency
is programmed using a single resistor and each of the
output voltages can be independently shutdown. The
LTC3520 comes in a 24 pin 4×4 QFN package. These
features make the DC1062 demo board an ideal circuit
for use in Li-Ion battery-powered, hand-held applica-
tions.
Design files for this circuit board are available. Call
the LTC factory.
LTC is a trademark of Linear Technology Corporation
QUICK START PROCEDURE
Refer to Figure 1 for proper measurement equipment
setup and follow the procedure below:
1.
Start with Loads 1, 2 and 3 set to 0A.
2.
Set Power Supply anywhere between 2.2V to 5.5V.
3.
Loads 1, 2 and 3 can be set from 0 – 500mA, 0 –
600mA and 0 – 200mA respectively. Load 1 can be
set up to 1A for Vin > 3V.
