Renesas Brings Rad-Tol PWM Controller and GaN FET Driver to the Smallsat Market

Renesas has introduced the industry’s first plastic-packaged, radiation tolerant PWM controller and GaN FET driver developed for DC/DC power supplies in smallsats and launch vehicles, bringing cutting-edge IC technology combined with optimal cost and radiation performance to the smallsat market.

The ISL71043M single-ended current mode PWM controller and ISL71040M low-side GaN FET driver provide the ideal isolated flyback and half-bridge power stages, as well as motor control driver circuits for satellite buses and payloads. As private ‘new space’ companies have begun launching smallsats to form large constellations that operate in multiple LEO planes, smallsat mega-constellations also work to provide global broadband Internet links, as well as high-resolution Earth observation imaging for sea, air, and land asset tracking. The new power supply solution delivers the size, cost, and performance that new space customers need for five year mission profiles in LEO planes.

The ISL71043M PWM controller:

  • Provides fast signal propagation and output switching in a small 4mm x 5mm SOIC plastic package, reducing PCB area up to 3x compared to competitive ceramic packages. 
  • Features a 5.5mA max supply current that reduces power loss more than 3x, and an adjustable operating frequency — up to 1 MHz – that enables higher efficiency and the use of smaller passive filter components.


The ISL71040M low-side GaN FET driver:

  • Safely drives Renesas’ rad-hard GaN FETs in isolated topologies and boost type configurations by precisely controlling the gate driver voltage to +3/-5% over temperature and radiation. It also includes floating protection circuitry to eliminate unintentional switching.
  • Operates with a supply voltage between 4.5V and 13.2V, a gate drive voltage (VDRV) of 4.5V, and includes both inverting and non-inverting inputs.
  • Features split outputs that adjust the turn-on and turn-off speeds, and high current source and sink capability that enable high frequency operation.


Both the ISL71043M and ISL71040M are characterization tested at a TID of up to 30krads(Si), and for SEE at a LET of 43MeV•cm2/mg. Both devices operate over an extended temperature range of -55°C to +125°C.

 The ISL71043M PWM controller and ISL71040M GaN FET driver can also be combined with the ISL73024SEH 200V GaN FET or ISL73023SEH 100V GaN FET, and ISL71610M passive-input digital isolator to create a variety of power stage configurations.

Both the ISL71043M and ISL71040M devices are available now. More information can be found here.

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