Analog Devices Inc. LTC3311 & LTC3311S Step-Down Silent Switchers

Analog Devices Inc. LTC3311 and LTC3311S Synchronous Step-Down Silent Switchers provide up to 12.5A of output current from a 2.25V to 5.5V input supply. The LTC3311 has a Silent Switcher 1 architecture and the LTC3311S has a Silent Switcher 2 architecture. Both variants integrate internal hot loop bypass capacitors to achieve both low EMI and high efficiency at switching frequencies as high as 5MHz. Multi-phasing parallel converters are readily implemented for systems with higher power requirements.

The Analog Devices Inc. LTC3311 and LTC3311S use a constant frequency, peak current mode control architecture for fast transient response. A 500mV reference allows for low voltage outputs. 100% duty cycle operation delivers low dropout.

The LTC3311 and LTC3311S also include a Power Good signal when the output is in regulation, precision enable threshold, output overvoltage protection, thermal shutdown, a temperature monitor, clock synchronization, mode selection, and output short circuit protection.

The pin-compatible LTC3311 and LTC3311S Step-Down Silent Switchers are available in a compact 3mm x 3mm LQFN-18 package. Both variants are AEC-Q100 qualified for automotive applications.


  • Automotive/industrial/communications
  • Servers, telecom power supplies
  • Distributed DC power systems (POL)
  • FPGA, ASIC, µP core supplies


  • Pin Compatible with LTC3310 and LTC3310S 
  • Silent Switcher
    • LTC3311: Silent Switcher 1 Architecture
    • LTC3311S: Silent Switcher 2 Architecture
  • High-efficiency 4.5mΩ NMOS and 16mΩ PMOS
  • Wide bandwidth, fast transient response
  • Safely tolerates inductor saturation in overload
  • VIN range: 2.25V to 5.5V
  • VOUT range: 0.5V to VIN
  • VOUT accuracy: ±1% with Remote Sense
  • Peak current-mode control
  • 35ns minimum on-time
  • Programmable frequency to 5MHz
  • Precision 400mV enable threshold, 1µA in shutdown
  • Output soft-start with voltage tracking
  • Power Good output
  • Die temperature monitor,
  • Configurable for paralleling power stages in forced continuous mode
  • Thermally-enhanced 3mm × 3mm LQFN package
  • AEC-Q100 qualified for automotive applications

Typical Application

Application Circuit Diagram - Analog Devices Inc. LTC3311 & LTC3311S Step-Down Silent Switchers
Published: 2021-01-26 | Updated: 2023-01-21