QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1177 DUAL BUCK-BOOST/ BUCK SYNCHRONOUS CONVERTERS LTC3522 DESCRIPTION Demonstration circuit DC1177 is a micropower dual Buck-Boost/Buck synchronous converter based on the LTC3522 monolithic regulator. The DC1177 has an input voltage range of 2.4V to 4.2V and outputs 3.3V @ 300mA and 1.8V @ 200mA. The converters can be set for Fixed Frequency (PWM) or Burst Node, providing high conversion efficiency over a wide range of load cur- rents. The LTC3522 comes in a 16 lead 3x3 QFN package. These features make the DC1177 demo board an ideal circuit for use in Li-Ion battery-powered, hand-held applications such as PDAs, MP3 Players, and Personal Navigation Devices. Design files for this circuit board are available. Call the LTC factory. QUICK START PROCEDURE Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1. Set Load1 between 0A 0A 200mA. 400mA and Load2 between 2. Set the Power Supply to ~ 3.6Vin 3. VIN can be adjusted between 2.4V and 4.2V (note: max output current for VOUT1 is lower than 400mA at VIN below 3.0V). Figure 1. Proper Measurement Equipment Setup 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1177 DUAL BUCK-BOOST/ BUCK SYNCHRONOUS CONVERTERS 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1177 DUAL BUCK-BOOST/ BUCK SYNCHRONOUS CONVERTERS 3