Dual 1-A regulator shuts down to 5 µA

July 28, 2014 // By Graham Prophet
LTC3622 is a high efficiency, 17V input capable synchronous buck regulator that delivers dual 1A continuous current to outputs as low as 0.6V. Synchronous rectification delivers efficiencies as high as 95%, while Burst Mode operation requires only 5 µA of no-load quiescent current.

The LTC3622 switches at a fixed 1 MHz frequency, whereas the LTC3622-2 switches at 2.25 MHz. Their constant frequency, current-mode architecture minimises switching noise while offering very fast line and load transient response. The LTC3622/-2 operates from an input voltage range of 2.7V to 17V, suiting it to single or dual cell Li-Ion applications as well as 5V or 12V intermediate bus systems. The combination of its 3 x 4 mm DFN package, high switching frequency and small, low cost capacitors and inductors ensures a compact solution footprint.

The LTC3622/-2's 75 nsec minimum on-time enables it to step-down 14V inputs to 2.5V with a 2.25 MHz switching frequency without pulse skipping, making it suitable for automotive applications that must keep switching noise above the AM radio band. Its 5 µA quiescent current makes it well suited for always-on applications demanding maximum battery run time. For applications that require the lowest possible noise, the LTC3622/-2 can be configured to run in pulse-skipping mode or synchronised to an external clock, reducing noise and potential RF interference. Features include a power-good voltage monitor for each channel, internal compensation and thermal protection.

Pricing for both package and frequency options starts at $3.75 (1,000), or an industrial-grade version that operates over the -40°C to 125°C junction temperature range costs $4.19.

Linear Technology; www.linear.com/product/LTC3622