42-V, 750-mA, 2.2-MHz step-down dc/dc converter only requires 2.5-uA quiescent current
The device’s Burst Mode operation offers ultralow quiescent current, making it well suited for applications such as automotive or industrial systems, which demand always-on operation and optimum battery life.
The design of the LT3973 maintains a minimum dropout voltage of 530 mV when the output voltage drops below the programmed output voltage, ideal for applications subjected to scenarios such as automotive cold-crank. Switching frequency is user programmable from 200 kHz to 2.2 MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of its 10-lead 3 mm x 3 mm DFN-10 (or thermally enhanced MSOP) package and high switching frequency keeps external inductors and capacitors small, providing a compact, thermally efficient footprint.
The LT3973 utilizes a high efficiency 250 mV CESAT switch, with the necessary boost and catch diodes, 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 10 mV PK-PK . Special design techniques and a new high voltage process enable high efficiency over a wide input voltage range, and the LT3973’s current mode topology enables fast transient response and excellent loop stability. Other features include a power good flag, internal catch diode current limit and thermal protection.
The LT3973EDD is packaged in a 3mm x 3mm DFN-10, and the LT3973EMSE is in a thermally enhanced MSOP-10, priced starting at $2.75 and $2.85 each, respectively for 1,000 piece quantities.
The LT3973IDD and LT3973IMSE are tested and guaranteed to operate from a -40 to 125°C operating junction temperature and are priced at $3.03 and $3.14 each, respectively in 1,000 piece quantities.
The LT3973HDD and LT3973HMSE are tested and guaranteed to operate from a -40 to 150°C operating junction temperature and are priced at $3.38 and $3.49 each, respectively in 1,000 piece quantities All versions are available from stock.
More information about the LT3973 step-down switching regulator at