QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1062 DUAL BUCK-BOOST + BUCK SYNCHRONOUS CONVERTERS LTC3520 DESCRIPTION Demonstration circuit 1062 is a micropower synchronous 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 4x4 QFN package. These features make the DC1062 demo board an ideal circuit for use in Li-Ion battery-powered, hand-held applications. 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. 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1062 DUAL BUCK-BOOST + BUCK SYNCHRONOUS CONVERTERS Figure 1.:Proper Measurement Equipment Setup 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1062 DUAL BUCK-BOOST + BUCK SYNCHRONOUS CONVERTERS 3 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1062 DUAL BUCK-BOOST + BUCK SYNCHRONOUS CONVERTERS 4