The TPSI310x is a fully integrated, isolated switch driver with integrated bias, which when combined with an external power switch, forms a complete isolated solid state relay solution. With a nominal gate drive voltage of 15.8-V with 1.5/3.0-A peak source and sink current, a large variety of external power switches such as MOSFETs, IGBTs, or SCRs can be chosen to meet a wide range of applications. The TPSI310x generates its own secondary bias supply from the power received from its primary side, so no isolated secondary supply bias is required.

The secondary side provides a regulated, floating supply rail of 15.8-V for driving a large variety of power switches with no need for a secondary bias supply. The TPSI310x can support driving single power switch, dual back-to-back, parallel power switches for a variety of AC or DC applications. The TPSI310x integrated isolation protection is extremely robust with much higher reliability, lower power consumption, and increased temperature ranges than those found using traditional mechanical relays and optocouplers.

The TPSI310x integrates a communication back-channel that transfers various status information from the secondary side to the primary side via open-drain outputs, PGOOD (Power Good), FLT1 (Fault 1), and ALM1 (Alarm 1). Two high-speed comparators with an integrated shared voltage reference are used to assert FLT1 and ALM1. When the comparator input, FLT1_CMP, exceeds the voltage reference, the driver is immediately asserted low and FLT1 on the primary side is driven low after some latency, indicating a fault has occurred. This is useful for directly disabling the external switch from the secondary on critical events with low latency, such as short circuit detection. When the comparator input, ALM1_CMP, exceeds the voltage reference, ALM1 signal is asserted low on the primary side, but no action is taken by the driver. This may be useful as an alarm or warning indicator.