LT3990's Burst Mode operation provides ultralow quiescent current, well suited for automotive or industrial systems, which demand always-on operation and optimum battery life. Switching frequency is user programmable from 200kHz to 2.2MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of its 10-lead 3mm x 2mm DFN-10 (or MSOP) package and high switching frequency keeps external inductors and capacitors small, providing a very compact, thermally efficient footprint.
The LT3990 utilizes a high efficiency 550mA, 300mV switch, with the necessary boost and catch Schottky diodes, oscillator, control and logic circuitry integrated into a single die. Low ripple Burst Mode operation ensures high efficiency at low output currents while keeping output ripple below 5mVPK-PK. Special design techniques and a new high voltage process enable high efficiency over a wide input voltage range, and the LT3990's current mode topology enables fast transient response and excellent loop stability. Other features include a power good flag soft-start capability and output short protection.