Buck converter steps 36 V down to 3.3 V

The LTC3646 is a 40-V input capable synchronous buck converter that delivers 1-A continuous output current from a 3 x 4-mm DFN-14 (or thermally enhanced MSOP16) package. It uses a controlled on-time architecture that can step inputs as high as 36− down to 3.3−V with switching frequencies from 200 kHz to 3 MHz, keeping switching noise out of critical frequency bands, such as AM radio.

The synchronous buck converter operates from an input voltage range from 4 to 40 V. It suits automotive and industrial applications that require high voltage input capability, high efficiency and high switching frequencies. The device delivers transient responses even with duty cycles less than 10%. Its internal synchronous rectification delivers efficiencies as high as 95% and requires only 140−µA of quiescent current, to help maximize battery run time. (Ea/1,000: LTC3646EDE/-1 and LTC3646EMSE/-1, from $2.85; extended temperature LTC3646IDE/-1 and LTC3646IMSE/-1, from $3.14; high temperature LTC3646HDE/-1 and LTC3646HMSE/-1, from $3.39 — available now.)

By Paul O’Shea

Linear Technology , Milpitas , CA
Sales Office 408-428-2050
www.linear.com