Fast-starting load switch for safety systems has minimal delay response

STMicroelectronics has released the IPS1025HF fast-starting high-side power switch for employment in safety systems requiring minimal power-on delay time.

The switch responds to turn-on and turn-off signals in lower than 60µs, even considering the Vcc power-on and off, allowing protective systems to provide a specified SIL. The compact devices withstand severe industrial operating conditions, providing a wide input-voltage range from 8.65V to 60V and tolerating up to 65V on the input pin. Applications include power control for PLCs, vending machines, factory-automation I/O peripherals, and CNC machines.

Like similar single-channel and dual devices in the company's intelligent power switch family, the switch has two programmable current-limit settings that enable the user to program a higher current limitation value at power switch activation. This improves flexibility for driving loads, including bulb lamps, motors, and capacitive loads that need high initial peak current.

The output stage is an N-channel Power MOSFET with a typical Rds(on) of 12.5mOhm at ambient temperature, assuring high energy efficiency and low thermal dissipation. The MOSFET is internally limited at 2.5A minimum output current and has single-pulse avalanche energy up to 14J, which provides reliability for handling inductive loads. There is also an integrated active clamp for fast demagnetisation.

The switch comprises protection against undervoltage, overvoltage, overload, short circuit, ground disconnection, and Vcc disconnection. On-chip diagnostics incorporates individual signalling of output overload and junction overtemperature, and there is an extra thermal sensor to detect excessive case temperature. The device is created to meet IEC 61000-4-2 ESD, IEC 61000-4-4, and IEC 61000-4-5 specifications for ESD, fast-transient, and surge immunity.

For swift evaluation, the X-NUCLEO-OUT15A1 expansion board contains an IPS1025HF with associated circuitry ready to connect to STM32 Nucleo development boards. A demonstration firmware pack, STSW-OUT15F4, and industrial-automation system design GUI, STSW-IFAPGUI, are also offered and allow users to realise an entire industrial-automation environment on the desktop.