DC/DC converter for RF and automotive applications

2nd May 2014

Nat Bowers

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Datasheet

A synchronous, current-mode buck-boost DC/DC converter, the LTC3114-1 delivers up to 1A of continuous output current from a variety of power sources, including single-cell Li-Ion, 24/28V industrial rails and 40V automotive inputs. Introduced by Linear Technology, the device incorporates four internal low RDS(ON) N-channel MOSFETs to deliver efficiencies of up to 96%.

The LTC3114-1’s 2.2-40V input and 2.7-40V output range provides a regulated output with inputs above, below or equal to the regulated output, maximising power source flexibility and extending battery run time over step-down only solutions. The proprietary low noise buck-boost topology incorporated in the LTC3114-1 provides a continuous jitter-free transition between buck and boost modes, making it suited for RF and other noise-sensitive applications.

The device’s selectable Automatic Burst Mode operation lowers quiescent current to only 30µA, improving light load efficiency and extending battery run time. For noise-sensitive applications, Burst Mode operation can be disabled. The LTC3114-1 uses a constant 1.2MHz switching frequency and features pin-programmable average output current and current monitor. Proprietary buck-boost PWM circuitry ensures low noise and high efficiency while minimising the size of external components. The combination of tiny externals and a 3x5mm DFN or TSSOP-16E package provides a compact solution footprint.

For noise-sensitive applications, Burst Mode operation can be disabled. Furthermore, current-mode control improves line and load transient responses while keeping compensation simple. Additional features include internal soft-start and inrush current limit, undervoltage lockout, thermal overload protection, short-circuit protection and output disconnect.

LTC3114EDHC-1 is available in a 16-lead 3x5mm DFN package and the LTC3114EFE-1 is in a thermally enhanced 16-lead TSSOP package. Pricing starts at $3.95 (USD) each for 1,000 unit quantities. Industrial grade versions, the LTC3114IDHC-1 and LTC3114IFE-1, are guaranteed to operate over the -40 to +125°C operating junction temperature range, priced at $4.35 (USD) and $4.51 (USD) each, respectively, in 1,000 unit quantities. High temperature grade versions, the LTC3114HDHC-1 and LTC3114HFE-1, are guaranteed to operate over the -40 to +150°C operating junction temperature range, priced at $4.60 (USD) and $4.76 (USD) each, respectively, in 1,000 unit quantities. Finally high reliability versions, the LTC3114MPDHC-1 and LTC3114MPFE-1, are guaranteed to operate over the -55 to +150°C operating junction temperature range, priced starting at $11.73 (USD) each, in 1,000 unit quantities. All versions are available from stock.