Demonstration Circuit DC3203A features the LTC3304A, 5 V, 6 A synchronous step-down silent switcher operating as a 2 MHz, 3.3 V to 1.2 V, 6 A buck regulator. The LTC3304A supports adjustable output voltages from 0.5 V to VIN. The LTC3304A is a compact, high efficiency, and high-speed synchronous monolithic step-down switching regulator. A minimum on-time of 27 ns enables high VIN to low VOUT conversion.
The DC3203A operating mode can be selected as Burst Mode operation, skip (PS), or forced continuous (FC) mode. Setting JP1 to the SKIP position allows the LTC3304A to sync to a clock frequency from 1.6 MHz to 2.4 MHz. The LTC3304A operates in forced continuous mode when syncing to an external clock.
The DC3203A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section of the user guide. The red lines in the EMI performance graphs show the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.
The LTC3304A data sheet gives a complete description of the device, operation, and application information. Full specifications on the LTC3304A are available in the LTC3304A data sheet available from Analog Devices, Inc., and must be consulted with the user guide when using the DC3203A evaluation board. The LTC3304A is assembled in a 2 mm × 2 mm FCQFN package with side wettable flanks (SWF) for visual solder inspection. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.
