100V, 1A, synchronous step-down regulator: Iq of 7µA

September 04, 2015 // By Graham Prophet
LT8631 is a 1A, 100V-input-capable synchronous step-down switching regulator. Synchronous rectification delivers efficiency as high as 90% while Burst Mode operation keeps quiescent current under 7µA in no-load standby conditions.

Its 3V to 100V input voltage range suits it for 48V automotive systems, dual battery transportation, industrial and 36V to 72V telecom applications. Its internal high efficiency switches deliver up to 1A of continuous output current to voltages as low as 0.8V. The LT8631’s Burst Mode operation offers ultralow quiescent current, suiting it for applications such as automotive “always-on” systems. The LT8631’s unique design maintains a minimum dropout voltage, enabling it to operate with duty cycles up to 99%. Its resistor-programmable 100 kHz to 1 MHz frequency range and synchronisation capability enable optimisation between efficiency and external component size. The LT8631’s 20-lead TSSOP package with high voltage lead spacing ensures a compact, thermally efficient footprint for high voltage applications.

The LT8631 uses internal top and bottom high efficiency power switches 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 10 mVP-P. High efficiency is maintained over a wide input voltage range, and the LT8631’s current mode topology enables fast transient response and excellent loop stability. Other features include robust short-circuit protection, a power-good flag, output voltage tracking and thermal protection.

The LT8631EFE occupies a thermally enhanced TSSOP-20 package. An industrial temperature version, the LT8631IFE, is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature. A high temperature version, the LT8631HFE, is tested and guaranteed to operate from a -40°C to 150°C operating junction temperature. Pricing starts at $3.60 (1,000).

Linear Technology; www.linear.com/product/LT8631