Chip duo targets power supplies for small satellites

By Majeed Ahmad, contributing writer

Renesas Electronics claims to have launched the space industry’s first plastic-packaged, radiation-tolerant PWM controller and gallium-nitride (GaN) FET driver for DC/DC power supplies in small satellites (smallsats) and launch vehicles. The chip duo is especially designed for isolated flyback and half-bridge power stages and motor control driver circuits in satellite buses and payloads.

The smallsats form large constellations operating in multiple low Earth orbit (LEO) planes and provide global broadband internet links and high-resolution imaging for sea, air, and land asset tracking.

The ISL71043M PWM controller, which provides fast signal propagation and output switching, features maximum supply current of 5.5 mA, which reduces power loss by more than three times. Moreover, ISL71043M offers the adjustable operating frequency of up to 1 MHz, and that enables higher efficiency and the use of smaller passive filter components.

The ISL71040M, a low-side GaN FET driver, ensures reliable operation by precisely controlling the gate driver voltage to +3%/−5% in hostile temperature and radiation environments. The chip’s split outputs adjust the turn-on and turn-off speeds, and its high current source and sink capability enable high-frequency operation. The ISL71040M chip operates with a supply voltage between 4.5 V and 13.2 V, and it includes both inverting and non-inverting inputs.

Renesas said that both devices are characterization-tested at a total ionizing doze (TID) of up to 30 krads (Si) and for single-event effects (SEE) at a linear energy transfer (LET) of 43 MeV • cm² /mg. Both devices operate over an extended temperature range of −55°C to 125°C.

The ISL71043M PWM controller is available in a small 4 × 5-mm SOIC plastic package, which reduces the PCB area up to 3× compared to competitive ceramic packages. And the ISL71040M radiation-tolerant low-side GaN FET driver is available in an eight-lead 4 × 4-mm TDFN package.