Semtech launches ‘world’s smallest’ step up regulators for low voltage applications

The SC120, SC121 and SC122 are designed to boost inputs from 0.7V to a regulated output settable from 1.8 to 5V and are available in 1.5x2mm plastic packages. The devices are suitable for portable applications powered by alkaline, NiMH, or 1cell Li-ion batteries, or as point-of-load regulators in non-portable applications where a low voltage needs to be boosted to a higher voltage rail for localised use. Scott Brown, Semtech vice president of marketing for power management products, said: "The new SC120 platform sets the benchmark for its sophisticated features, performance, and ease of use within a tiny, thin, reliable, and green footprint." The SC120 incorporates 1.2MHz low noise PWM operation, an internal low-on-resistance switch and synchronous rectifier, automatic PSAVE mode for light-load efficiency and an anti-ringing circuit designed to dampen stray oscillations on the inductor terminal. For noise sensitive applications, the SC121 is designed to eliminate the PSAVE mode in favor of forced-PWM operation at all loads. For specialised keep-alive applications, the SC122 utilises PSAVE mode only and allows the output voltage to float high during shutdown by eliminating active discharge. It also limits the input to no more than 1.6V and the output to a fixed 3.3V. According to Semtech, the SC12x devices incorporate internal loop compensation and internal soft-start to minimise external components. Grounding the feedback pin enables internally fixed 3.3V regulation mode, which requires two ceramic capacitors and an inductor. For setting other output voltages from 1.8 to 5V via external feedback, two small resistors and a small feed-forward capacitor are added.