Boost convertor integrates more on-chip

Edited by the Electronicstalk editorial team Jun 15, 2006

A 1.2MHz current-mode synchronous boost DC/DC convertor features true output disconnect, inrush current limiting and reverse battery protection.

Linear Technology has announced the LTC3499/B, a 1.2MHz current-mode synchronous boost DC/DC convertor with true output disconnect, inrush current limiting and reverse battery protection.

Its internal switches provide a 750mA current limit (minimum) and can deliver output voltages as high as 6V from an input voltage range of 1.8 to 5.5V, making it ideal for single cell Li-ion and two or three dual cell alkaline/NiCd/NiMH applications.

The LTC3499/B delivers up to 175mA of continuous output current (at 5V) from dual alkaline cells.

Synchronous rectification enables efficiencies of up to 94%, and burst mode operation lowers quiescent current to only 20uA, providing maximum battery run-time in handheld applications.

For applications that require the lowest noise possible, the LTC3499B features continuous switching at light loads.

The combination of a DFN or MSOP package and a constant switching frequency of 750kHz minimise both inductor and capacitor sises, providing a tiny solution footprint required in handheld applications.

The LTC3499/B uses internal switches with an on-resistance of only 0.45ohm (N-channel) and 0.58ohm (P-channel) to deliver efficiencies as high as 94%.

Reverse battery protection protects both the IC and the load when battery polarity is reversed, and the true output disconnect feature allows the output to be completely discharged in shutdown.

This also limits the inrush of current during startup, minimising surge currents seen by the input supply.

Additional features include overvoltage protection, programmable soft-start and thermal protection.

For boost applications, requiring up to 175mA of output current, where reverse battery protection, a small solution size and low maximum battery run-time are defining factors, the LTC3499/B delivers an ideal solution.

LTC3499EDD and LTC3499EMS8 are available from stock in 8-lead DFN or MSOP packages, respectively.

Both have 1000-piece pricing starting at $2.15 each.

The "B" versions, LTC3499BEDD and LTC3499BEMS8, are also available from stock in 8-lead DFN or MSOP packages, respectively.

1000-piece pricing starts at $2.15 each.