Linear Technology 36 V, 3.5 A, 2.4 MHz step-down dc/dc draws 75 µA

Linear Technology has introduced the LT3680, a 3.5 A, 36 V step-down dc/dc switching regulator with a burst modeoperation said to keep quiescent current under 75 µA and output ripple below 15 mV (peak-to-peak). With an input voltage range from 3.6 V to 36 V, the device can be used in load dump and cold-crank conditions found in automotive applications.

An internal 4.6A, 95 mOhm switch can deliver up to 3.5 A of continuous output current to voltages as low as 0.79 V. Switching frequency is user programmable from 250 kHz to 2.4 MHz, enabling designers to optimize efficiency while avoiding critical noise-sensitive frequency bands. The switch, boost diode, oscillator, and control and logic circuitry are all integrated in a single chip. Other features include external synchronization (from 250 kHz to 2 MHz), a power good flag, and soft-start capability.

A compact (3 mm x 3 mm DFN-10 or thermally enhanced MSOP-10E) package and high switching frequency are said to keep external inductors and capacitors small and the device footprint compact and thermally efficient.

Pricing for the LT3680EDD and LT3680EMSE starts at $4.15 and $4.25 each, respectively for 1,000-piece quantities. The LT3680IDD and LT3680IMSE are tested and guaranteed to operate from a -40 °C to 125 °C operating junction temperature, priced at $4.98 and $5.10 each, respectively in 1,000-piece quantities.