Linear Technology has announced the LT3973 series of 750mA, 42V step-down switching regulator with integrated boost and catch diodes. The LT3973EDD is packaged in a 3x3mm dual flat no-lead-10, and the LT3973EMSE is in a mini small outline plastic-10. The LT3973IDD and LT3973IMSE are tested to operate from a -40 to 125°C operating junction temperature. The LT3973HDD and LT3973HMSE are tested to operate from a -40 to 150°C operating junction temperature.
The regulators' Burst Mode operation keeps quiescent current under 2.5µA in no load standby conditions. The regulators' 4.2 to 42V input voltage range makes them suitable for automotive and industrial applications. The internal 1.2A switch can deliver up to 750mA of continuous output current to voltages as low as 1.21V, says the company. The regulators' design maintains a dropout voltage of only 530mV when the output voltage drops below the programmed output voltage, suitable for applications subjected to scenarios such as automotive cold-crank. Switching frequency is user programmable from 200kHz to 2.2MHz.
The regulator utilises a 250mVCESAT switch, oscillator, control and logic circuitry integrated into a single die. The Burst Mode operation maintains output ripple below 10mVPK-PK. The regulator's current mode topology enables fast transient response and good loop stability, according to the company. Other features include a power good flag, internal catch diode current limit, thermal protection, accurate programmable under-voltage lockout, and shutdown current of 0.75μA.
