TPSI3050

The TPSI3050 is a fully integrated, isolated switch driver, which when combined with an external power switch, forms a complete isolated solid state relay (SSR). With a nominal gate drive voltage of 10 V with 1.5/3.0-A peak source and sink current, a large variety of external power switches can be chosen to meet a wide range of applications. The TPSI3050 generates its own secondary bias supply from the power received from its primary side, so no isolated secondary supply bias is required. Additionally, the TPSI3050 can optionally supply power to external supporting circuitry for various application needs.

The TPSI3050 supports two modes of operation based on the number of input pins required. In two-wire mode, typically found in driving mechanical relays, controlling the switch requires only two pins and supports a wide voltage range of operation of 6.5 V to 48 V. In three-wire mode, the primary supply of 3 V to 5.5 V is supplied externally, and the switch is controlled through a separate enable. Available in three-wire mode only, the TPSI3050S features a one-shot enable for the switch control. This feature is useful for driving SCRs that typically require only one pulse of current to trigger.

The secondary side provides a regulated, floating supply rail of 10 V for driving a large variety of power switches with no need for a secondary bias supply. The application can drive single power switches for DC applications or dual back-to-back power switches for AC applications, as well as various types of SCR. The TPSI3050 integrated isolation protection is extremely robust with much higher reliability, lower power consumption, and increased temperature ranges than traditional mechanical relays and optocouplers.

The power transfer of the TPSI3050 can be adjusted by selecting one of seven power level settings using an external resistor from the PXFR pin to VSSP. This action allows for tradeoffs in power dissipation versus power provided on the secondary depending on the needs of the application.