This reference design shows how to achieve overcurrent and overtemperature protection for a solid-state relay. The reference design features the TPSI3050-Q1 5-kVRMS reinforced isolated switch driver. TPSI3050-Q1 device integrates a laminate transformer to achieve isolation while transferring signal and power to the secondary side. This removes the need for any isolated bias supply. In addition, the TPSI3050-Q1 device can supply power to external circuitry located on the high voltage (HV) side. This reference design can support up to 500-VDC or 350-VAC switching with a max of 4-A loading conditions.

Features
No isolated secondary supply required
3-kVRMS reinforced isolation
500-VDC/350-VRMS load with 4-A max
Two-level overcurrent protection
>2-A 100-ms load disconnect delay
>5-A immediate load disconnect
Two-level overtemperature protection
>60°C LED visual warning
>90°C immediate load disconnect