LTC3308A/B Synchronous Step-Down Silent Switcher™ Analog Devices Inc. LTC3308A/B Synchronous Step-Down Silent Switcher™ is a very small, high efficiency, low noise, monolithic synchronous 4A step-down DC/DC converter. It operates from a 2.25V to 5.5V input supply. Using constant frequency, peak current mode control at switching frequencies up to 3MHz, and minimum on-time as low as 22ns, this regulator achieves fast transient response with small external components. A Silent Switcher architecture minimizes EMI emissions.