Switching regulator delivers 2.5A of continuous output current
Linear Technology Corporation announces the LT3975, a 42V step-down switching regulator that can deliver 2.5A of continuous output current and requires only 2.7µA of quiescent current. Similarly, the LT3976 can operate from a 40V input, delivers up to 5A of output current and requires only 3.3µA of quiescent current. Both devices offer a 4.2V to a nominal 40V input voltage range, making them ideal for automotive and industrial applications. Their internal high 75mOhm switches deliver efficiencies as high as 90 percent. The LT3975’s and LT3976’s Burst Mode operation offers ultralow quiescent current, a feature that is also well suited for automotive and industrial systems applications that demand always-on operation and optimum battery life. The devices’ unique design maintains a minimum dropout voltage of only 500mV when the input voltage drops below the programmed output voltage, a functional necessity in applications subject to automotive cold-crank conditions. Switching frequency is user-programmable from 200kHz to 2MHz, and synchronizable from 250kHz to 2MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of their 16-lead thermally enhanced MSOP package and high switching frequency keeps external inductors and capacitors small, providing a compact, thermally efficient footprint.The LT3975 and LT3976 use a high efficiency 75mOhm switch, with the 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 deliver high efficiency over a wide input voltage range, and their current-mode topology enables fast transient response and excellent loop stability. Other features include a power good flag, soft-start capability and thermal protection. The LT3975EMSE and the LT3976EMSE are packaged in a thermally enhanced MSOP-16, priced starting at $3.10 and $3.75 each, respectively for 1,000-piece quantities. The LT3975IMSE and LT3976IMSE are tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and are priced at $3.41 and $4.13 each, respectively in 1,000-piece quantities. The LT3975HMSE and LT3976HMSE are tested and guaranteed to operate from a -40°C to 150°C operating junction temperature and are priced at $3.66 and $4.38 each, respectively in 1,000-piece quantities All versions are available from stock.
Linear Technology Corporation