Isolated switch for high-voltage automotive and industrial applications

The Texas Instruments TPSI2140-Q1 is an isolated solid-state relay developed for high-voltage automotive and industrial applications. It utilises the company's high-reliability capacitive isolation technology and internal back-to-back MOSFETs to create a completely integrated solution requiring no secondary side power supply.

The entire primary side of the device needs only 9mA of input current, allowing the user to drive the VDD and EN pins from a single microcontroller GPIO and eradicating the necessity for an external low-side switch used in photo relay solutions. The user can also connect the VDD pin to a system supply between 5V–20V and drive the EN pin from a GPIO. The EN pin is fail-safe preventing any possibility of back powering the VDD supply.

The secondary side consists of back-to-back MOSFETs with a standoff voltage of ±1.2kV from S1 to S2. The device MOSFET's avalanche robustness and thermally conscious package design permit it to survive system-level High Potential (HiPot) screening and DC fast charger surge currents of up to 2mA without needing any external components.