DEMO MANUAL DC2131A LTC3623 15V, 5A Monolithic Synchronous Step-Down Regulator DESCRIPTION Demonstration circuit 2131A is a current mode DC/DC This board is suitable for a wide range of battery-powered, step-down Silent Switcher buck regulator featuring the point-of-load, DDR memory, Thermo Electric Cooler (TEC) LTC 3623. The board operates from an input range of 4V systems and other applications. The LTC3623 is available to 15V, and provides 5A of output current. The output in a low profile, 24-pin QFN package. For other output voltage of the demonstration board can be set from 0V to requirements, see the LTC3623 data sheet. V 0.5V. It operates at 1MHz and may be synchronized IN Design files for this circuit board are available at to an external clock. A soft-start feature controls output DEMO MANUAL DC2131A QUICK START PROCEDURE Demonstration circuit 2131A is easy to set up to evalu- 3. Turn on the power at the input. ate the performance of the LTC3623. Refer to Figure 1 NOTE: Make sure that the input voltage never for proper measurement equipment setup and follow the exceeds 15V. procedure below: 4. Check for the proper output voltage which is set using NOTE: When measuring the output voltage ripple, care must a jumper. Setting the jumper to the OPT position will be taken to avoid a long ground lead on the oscilloscope set the output voltage to 5V. probe. Measure the output voltage ripple by touching the 5. Once the proper output voltage is established, connect probe tip and ground ring directly across the last output a variable load capable of sinking 5A at 5V to the output capacitor as shown in Figure 1. terminals +V and V . Set the current for 0A. OUT OUT 1. Using an input power supply that is capable of 4V to a. If efficiency measurements are desired, an ammeter 15V, set the voltage to 12V. Then turn off the supply. or a resistor shunt that is capable of handling 5A DC 2. With power off, connect the supply to the input terminals can be put in series with the output load in order to +V and V . IN IN measure the DC3623As output current. a. If efficiency measurements are desired, an ammeter b. A Voltmeter with a capability of measuring at least 5V capable of measuring 5A DC or a resistor shunt can be can be placed across the output terminals in order to put in series with the input supply in order to measure get an accurate output voltage measurement. the DC1722As input current. NOTE: If there is no output, temporarily disconnect the b. A Voltmeter with a capability of measuring at least 15V load to make sure that the load is not set too high. can be placed across the input terminals in order to get 6. Adjust the load and/or input within the operating range an accurate input voltage measurement. and observe the output voltage regulation, ripple volt- age, efficiency and other desired parameters. dc2131afb 2