The LT3991’s Burst Mode operation offers ultralow quiescent current, making it well suited for applications such as automotive or industrial systems that demand always-on operation and optimum battery life. Switching frequency is user programmable from 200kHz to 2MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of its 10-lead 3mm x 3mm DFN or thermally enhanced MSOP packages and high switching frequency keep external inductors and capacitors small, providing a compact, thermally efficient footprint.
The LT3991 utilizes a high efficiency 1.7A, 440mOhm switch, with the necessary boost diode, oscillator, control and logic circuitry integrated into a single die. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mVPK-PK. Special design techniques and a new high voltage process enable high efficiency over a wide input voltage range, and the LT3991’s current mode topology enables fast transient response and excellent loop stability. Other features include a power good flag, soft-start capability, external clock synchronization and internal compensation.
