Analog Devices Inc. LTC3309A Demo Board DC2745A is designed to evaluate the performance of the LTC3309A synchronous 6A step-down DC/DC converter. This demo circuit's operating mode can be selected as Burst Mode® operation, skip, or Forced Continuous (FC) mode. The DC2745A demo circuit is set to a fixed 2MHz frequency by connecting RT to VIN through a 0Ω resistor, R9. The LTC3309A converter supports 0.5V to VIN adjustable output voltages and 1MHz to 3MHz operating frequencies. The desired frequency can be easily set by removing R9 and setting an appropriate resistor in the R4 location. This demo circuit consists of an EMI filter to reduce conducted EMI and this EMI filter can be included by applying the input voltage at the VIN EMI terminal. The LTC3309A converter operates in forced continuous mode when syncing to an external clock.
Features LTC3309A step-down silent switcher operating as a buck regulator
Operating mode can be selected as:
Skip or Forced Continuous (FC) mode
Setting JP1 to the FC/SYNC position will allow the LTC3309A to sync to a clock frequency from 1MHz to 3MHz
Circuit is set to a fixed 2MHz frequency by connecting RT to VIN through a 0Ω resistor, R9
Desired frequency can be easily set by removing R9 and setting an appropriate resistor in the R4 location
Consists of an EMI filter to reduce conducted EMI
2.25V to 5.5V input voltage range
1.183V to 1.217V output voltage range
6A output current
3MHz switching frequency
22ns top switch minimum on time
Analog Devices Inc. LTC3309A/B Synchronous Step-Down DC/DC Converters
Feature Silent Switcher™ architecture designed to minimise EMI/EMC emissions.