The TPSI2140-Q1 is an isolated solid state relay designed for high voltage automotive and industrial applications. TI's high reliability capacitive isolation technology in combination with back-to-back MOSFETs form a completely integrated solution requiring no secondary side power supply.

As seen in the Functional Block Diagram, the primary side consists of a driver which delivers power and enable logic information to each of the internal MOSFETs on the secondary side. The on-board oscillator controls the frequency of the driver's operation and the Spread Spectrum Modulation (SSM) controller varies the driver frequency to improve system EMI performance. When the enable pin is brought HI and the VDD voltage is above the UVLO threshold, the oscillator starts and the driver sends power and a logic HI across the barrier. When the enable pin is brought LO or the VDD voltage falls below the UVLO threshold, the driver is disabled. The lack of activity communicates a logic LO to the secondary side and the MOSFETs are disabled.

Each MOSFET on the secondary side has a dedicated full-bridge rectifier to form its local power supply and a receiver. The receiver determines the logic state delivered from the primary side through the capacitive isolation barrier and uses a slew rate controlled driver to drive the MOSFET's gate. Each receiver performs signal conditioning on the signals received across the barrier in order to filter common mode interference and ensure that the MOSFETs are controlled according to the logic sent by the primary side driver and the system.

The avalanche robust MOSFETs and the thermal benefits of the widened pins on the 11 DWQ package enable the TPSI2140-Q1 to support dielectric withstand testing (HiPot) and DC fast charger surge currents of up to 2 mA without requiring any external protection components.