QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 849 750MA, 1.2MHZ SYNCHRONOUS BOOST CONVERTER LTC3499EDD DESCRIPTION Demonstration circuit 849 is a 750mA, 1.2MHz Synchronous Boost Converter with Reverse Battery Protection featuring the LTC(R)3499EDD. The demo board demonstrates a DC/DC boost converter, with a 750mA switch current limit, providing a 3.3V output at 250mA from a two cell input voltage, or a 5V output at 170mA from either a two cell or a Li-ion battery. The LTC3499EDD offers integrated reverse battery protection up to -6V for both the part and the load, drawing typically less than 1uA of current. The input voltage of this supply can also be increased higher than the output, but thermal limitations reduce the output current that can be delivered. See Vin>Vout Operation section on the datasheet. The circuit also demonstrates the advantages of output disconnect and inrush current limiting. Small circuit size and low component count make the LTC3499EDD suitable for use in many spaceconscious applications such as Medical Equipment, Digital Cameras, MP3 Players, and other Portable Devices. Other integrated features include peak current limit, soft-start, antiringing control and thermal shutdown. Design files for this circuit board are available. Call the LTC factory. LTC is a trademark of Linear Technology Corporation Table 1. Performance Summary (TA = 25C) 3.3V Output PARAMETERS CONDITION VALUE Minimum Input Voltage 1.8V Maximum Input Voltage 3V Output Voltage VOUT VIN = 1.8V, IOUT =0mA to 250mA 3.3V 3% Output Voltage VOUT VIN = 3.0V, IOUT =0mA to 500mA 3.3V 3% Typical Output Ripple VOUT VIN = 1.8V, IOUT = 250mA 20mVP-P Typical efficiency VIN =2.4V , IOUT = 160mA 90% Table 2. Performance Summary (TA = 25C) 5V Output PARAMETERS CONDITION VALUE Minimum Input Voltage 1.8V Maximum Input Voltage 4.2V Output Voltage VOUT VIN = 1.8V, IOUT =0mA to 170mA 5V 3% Output Voltage VOUT VIN = 2.7V, IOUT =0mA to 270mA 5V 3% Output Voltage VOUT VIN = 4.2V, IOUT =0mA to 480mA 5V 3% Typical Output Ripple VOUT VIN = 2.7V, IOUT = 270mA 22mVP-P Typical efficiency VIN =2.7V , IOUT = 160mA 88% 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 849 750MA, 1.2MHZ SYNCHRONOUS BOOST CONVERTER QUICK START PROCEDURE Demonstration circuit 849 is easy to set up to evaluate the performance of the LTC3499EDD. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: NOTE: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the VIN or VOUT and GND terminals. See Figure 2 for proper scope probe technique. 1. Place jumpers in the following positions: JP1 Run. 2. With power off, connect the input power supply to VIN and GND. 3. Turn on the power at the input. 4. Check for the proper output voltages. NOTE: If there is no output, temporarily disconnect the load to make sure that the load is not set too high. NOTE: Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. JP2 3.3V or 5V (depending on output desired) Figure 1. Proper Measurement Equipment Setup Figure 2. Measuring Input or Output Ripple 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 849 750MA, 1.2MHZ SYNCHRONOUS BOOST CONVERTER 3