1.5-A monolithic synchronous buck-boost DC/DC converter delivers 95 percent efficiency
The LTC3111’s 2.5 V to 15 V input and output voltage range provides a regulated output from inputs above, below or equal to the regulated output. The low noise buck-boost topology incorporated into the LTC3111 delivers a continuous, jitter-free transition between buck and boost modes, making the device ideal for RF and other noise-sensitive applications that must maintain a low-noise, constant output voltage with a variable input power source.
In many applications, battery run time is extended over step-down only solutions. The LTC3111’s default 800 kHz switching frequency can be synchronized to an external 600KHz to 1.5 MHz clock, and its proprietary third-generation buck-boost PWM circuitry ensures low noise and high efficiency while minimizing the size of external components. The combination of tiny externals and a 3mm x 4mm DFN or MSOP-16E package provides a compact solution footprint.
The LTC3111 includes four internal low RDS(ON) N-channel MOSFETs and uses a single inductor to deliver efficiencies of up to 95%. User-selectable Burst Mode operation lowers quiescent current to only 49 µA, improving light load efficiency and further extending battery run time. For noise-sensitive applications, Burst Mode operation can be disabled. Other features include soft-start, overvoltage protection, short-circuit protection, thermal shutdown and output disconnect.
Availability and Pricing
The LTC3111EDE is available in a 14-lead 3 mm x 4 mm DFN package and the LTC3111EMSE is offered in a thermally enhanced 16-lead MSOP package.
Pricing starts at $3.50 each and $3.60 each, respectively. Industrial grade versions, the LTC3111IDE and LTC3111IMSE, are guaranteed to operate over the -40°C to 125°C operating junction temperature range and are priced starting at $3.85 each and $3.96 each, respectively. High temperature grade versions, the LTC3111HDE and LTC3111HMSE, are guaranteed to operate over the -40°C to 150°C operating junction temperature range and are priced starting at $4.16 each and $4.21 each, respectively.
High reliability grade versions, the LTC3111MPDE and LTC3111MPMSE, are guaranteed to operate over the -55°C to 150°C operating junction temperature range and are priced starting at $10.40 each and $10.69 each, respectively. All pricing is for 1,000 piece quantities and all versions are available from stock.
More information about the LTC3111 synchronous buck-boost converter at