STMicroelectronics has introduced the a family of devices optimized to protect the Low Noise Block (LNB) voltage regulator in satellite set-top-box applications against lightning and electrical overstress surges. The LNBTVSx-22x range provides 3kV, 4kV and 6kV optimized protection (8/20µs) devices that fully comply with the LNB supply voltage and IEC61000-4-5 protection standards. Because of their exterior mounting, satellite aerials and the LNB circuitry are vulnerable to lightning, which can cause current surges at the LNB voltage regulator inputs that typically range from 250A when 3kV is applied, to 500A when 6kV is applied.

The voltage-regulator ICs cannot withstand such powerful energy pulses and require an external protection device. Although standard lightning protection devices are available, they are not optimized for this particular application. Compatible with all LNB voltage regulator types, the devices offer clamping voltage (VCL) from 30V to 35V and a forward voltage (VF) of 1.2V at IF = 3A. The devices are available in axial (DO-201) and SMD (SMB and SMC) packages, are UL recognized, and are in volume production. Prices range from $0.20 (3kV) to $0.45 (6kV) for 2500 pieces.