Wide-input step-down regulator saves power

Edited by the Electronicstalk editorial team Dec 27, 2007

Burst Mode operation offers ultralow quiescent current for applications such as automotive or telecomms systems demanding always-on operation and optimum battery life.

Linear Technology has released the LT3680, a 3.5A/36V step-down switching regulator with Burst Mode operation to keep quiescent current under 75uA.

The LT3680 operates within an input range of 3.6 to 36V, making it ideal for load dump and cold-crank conditions found in automotive applications.

Its 4.6A internal switch can deliver up to 3.5A of continuous output current to voltages as low as 0.79V.

The LT3680's Burst Mode operation offers ultralow quiescent current, well suited for applications such as automotive or telecomms systems, which demand always-on operation and optimum battery life.

Switching frequency is user programmable from 250kHz to 2.4MHz, enabling the designer to optimise efficiency while avoiding critical noise-sensitive frequency bands.

Its 3 x 3mm DFN-10 package (or thermally enhanced MSOP-10E) and high switching frequency keep external inductors and capacitors small, providing a compact, thermally efficient footprint.

The LT3680 uses a high efficiency 4.6A, 95mohm switch, with the necessary boost diode, oscillator, control and logic circuitry integrated into a single chip.

Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV peak-peak.

Special design techniques used in the LT3680 enable high efficiency over a wide input voltage range, and the device's current mode topology enables fast transient response and excellent loop stability.

Other features include external synchronisation (from 250kHz to 2MHz), a power good flag and soft-start capability.

Pricing for the LT3680EDD and LT3680EMSE starts at US $4.15 and $4.25 each, respectively, for 1000-piece quantities.

The LT3680IDD and LT3680IMSE are tested and guaranteed to operate from a -40 to +125C operating junction temperature, priced at US $4.98 and $5.10 each, respectively, in 1000-piece quantities.

All versions are available from stock.