DC1213A Analog Devices

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1213 DUAL MICROPOWER SYNCHRONOUS BUCK AND BOOST CONVERTER LTC3523 DESCRIPTION Demonstration circuit DC1213 is a micropower dual startup. Jumpers are provided for shutting down Buck and Boost synchronous converter based on the VOUT1 and VOUT2 independently, for Vout sequenc- LTC3522 monolithic regulator. The DC1213 has an in- ing, Changing Switching modes Fixed PWM or burst put voltage range of 1.8V all the way up to 4.2V de- and for choosing between 3.3V and 5V for VOUT1. The pending on the Vout1 settings. Since Vout1 is a boost LTC3522 comes in a 16 lead 33 QFN package. These converter, Vin must be below the Vout1 voltage at all features make the DC1213 demo board an ideal circuit times. The board is configured at the factory for Vout1 for use in Li-Ion battery-powered, hand-held applica- at 3.3V 200mA with Vin being limited to 1.8V to tions such as PDAs, MP3 Players, and Personal Navi- 3.2V. Vout2 is fixed at 1.2V 200mA. See the tables gation Devices. below for all of the Vin vs Vout 1 operating limits as Design files for this circuit board are available. Call the well as the default settings. The converters can be LTC factory. set for Fixed Frequency (PWM) or Burst Mode, which provides high conversion efficiency over a wide range of load currents. Both VOUTs can be sequenced on JP1 = 3.3V VIN = 1.8V 3.2V VOUT1 = 3.3V 200mA * JP1 = 5.0V VIN = 2.7V 4.2V VOUT1 = 5V 200mA JP1 = 5.0V VIN = 1.8V 2.7V VOUT1 = 5V 125mA Jumper Function Default Value JP1 VOUT1 Voltage 3.3V JP2 VOUT1 Shutdown ON JP3 Sequence VOUTs YES JP4 VOUT1 Shutdown ON JP5 Burst or Fixed PWM mode Burst QUICK START PROCEDURE Refer to Figure 1 for proper measurement equipment 2.7V and 4.2V for VOUT1 = 3.3V (note: max output setup and follow the procedure below: current for VOUT1 is lower than 400mA at VIN below 3.0V). 1. Set Load1 between 0A 200mA and Load2 be- tween 0A 200mA. 2. Set the Power Supply to ~ 3.0Vin 3. VIN can be adjusted between 1.8V and 3.2V for VOUT1 = 3.3V and VIN can be adjusted between 1111 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1213 DUAL MICROPOWER SYNCHRONOUS BUCK AND BOOST CONVERTER Figure 1. Proper Measurement Equipment Setup 2222