DC2748A - Schematic9/25/2020
Demonstration Circuit DC2748A features the LTC3315B dual 5V, 2A Synchronous Step-Down DC/DC regulators operating at 6MHz. One regulator provides a 1.8V output and the other provides 2.0V, both up to a 2A load. The LTC3315B supports adjustable output voltages from 0.5V to VIN, operating frequencies from 3MHz up to 10MHz. The LTC3315B is a compact, high efficiency, and high speed synchronous monolithic step-down switching regulator. Fast minimum on-time of 25ns enables high VIN to low VOUT conversion at high frequency.
The DC2748A operating mode may be selected as Burst Mode operation, Skip mode or Forced Continuous (FC) mode. Setting JP1 to the FC/SYNC position will allow the LTC3315B to sync to a clock frequency from 3MHz to 10MHz. The LTC3315B operates in Forced Continuous mode when syncing to an external clock.
The LTC3315B data sheet gives a complete description of the device, operation and application information. The data sheet must be read in conjunction with the demo manual. The LTC3315B is assembled in a 2mm × 2mm LQFN package with exposed pads for low thermal resistance. The PCB Considerations section in the data sheet.
The Efficiency vs Load graph on the demo manual shows the efficiency and the power loss of the circuit with a 3.3V input in Burst Mode operation.