STEC01PUR Ground Path Safety Switch with programmable timers

The STEC01 is an integrated programmable 12 mΩ power switch managed by the timer based circuitry.

The device has 3 timers designed to interrupt the ground path of a power application after a maximum on-time and inhibits the restart of the platform during a cooling window. The maximum on-time can be set from few seconds to hundreds of seconds, while the cooling window can be programmed to 69, 345 and 1380 seconds.

3 multi-level input pins, combined with a programmable oscillator and a fixed oscillator, are used to set the timing.

An input continuous or pulsed signal applied to the PWM pin starts the internal logic and counters. In case of a normal operation, as soon as the activity on the PWM pin stops, the device automatically enters idle mode, waiting for a new valid PWM signal to be applied. If the device detects a fault condition, a reset pulse is generated and the safety MOSFET is turned off and managed according to a predefined state machine.

The STEC01 has a continuous current capability up to 7 A through the internal power MOSFET. A higher current can be supported by using an external power transistor driven through GDRV pin.

A rising edge on the HWRESET input pin generates a 57 ms pulse on the RESETFAULT pin. This function can be used to notify the connection of an external power source (e.g. USB).