STMicroelectronics Launches Fast-Start Load Switch for Safety Systems

China, September 6, 2022 - STMicroelectronics has launched the IPS1025HF fast-start high-side power switch, targeting safety systems that require extremely short power-on delay times.

Even considering the Vcc power on and off conditions, the on and off response time of the IPS1025HF is still less than 60µs, ensuring that the safety protection system reaches the specified safety integrity level (SIL). Supporting a wide input voltage of 8.65V to 60V and a maximum input pin tolerance voltage of 65V, this compact device can withstand the harsh working conditions of industrial applications. Target applications include programmable logic controllers (PLCs), vending machines, factory automation I/O peripherals, and power control for computer numerical control (CNC) machine tools.

Like similar single- and dual-channel members of ST’s Intelligent Power Switch family, the IPS1025HF has two programmable current-limit settings, allowing the user to set a high current-limit value when the power switch is activated, thus increasing flexibility in driving loads that require high initial peak currents, such as light bulbs, motors, and capacitive loads .

The output stage is an N-channel power MOSFET with a typical on-resistance Rds(on) of 12.5mOhm at ambient temperature, ensuring high switching efficiency and low heat dissipation. The MOSFET internally limits the minimum output current to 2.5A and the maximum single-pulse avalanche energy to 14J, which can handle inductive loads more reliably. The new product also integrates a fast demagnetization active clamp circuit internally.

The switch's safety features include undervoltage protection, overvoltage protection, overload protection, short-circuit protection, ground disconnect protection, and Vcc disconnect protection. On-chip diagnostic pins include independent output overload and junction overtemperature signals, and an additional thermal sensor detects if the package temperature is too high. The device complies with IEC 61000-4-2 ESD, IEC 61000-4-4, and IEC 61000-4-5 ESD, fast transient, and surge immunity test specifications .

In order to facilitate developers to quickly evaluate the performance of the device, the X-NUCLEO-OUT15A1 expansion board integrates IPS1025HF and related circuits, which can be directly plugged into the STM32 Nucleo development board. The development kit also includes the STSW-OUT15F4 demonstration firmware package and the STSW-IFAPGUI industrial automation system design GUI graphical user interface software, allowing users to realize a complete industrial automation environment on the desktop.

The IPS1025HF is in production now and is available in PowerSSO-24 and QFN48L packages.