Intelligent power switches are fast starters for safety systems
Intelligent power switches from STMicroelectronics now include fast-starting devices. The IPS160HF and IPS161HF satisfy standardised requirements for interface types C and D in Safety Integrity Level (SIL) Class 3 applications.
They have a power-on delay time of less than 60 micro seconds and a wide input voltage range of 8.0 to 60V, together with maximum switch resistance (RDS(on)) of 120mOhm and10 micro seconds rise/fall time with 20 microseconds propagation delay. According to STMicro, these devices combine design flexibility, low power dissipation, and fast response. Extended diagnostics indicate open load, over-current cut-off and over-temperature shutdown; features which facilitiate the design of safety-instrumented functions.
The IPS160HF and IPS161HF drive complex resistive, capacitive, and inductive loads with one side connected to ground, such as valves, relays, and lamps. In addition to SIL-rated applications such as safety sensors, they can be used in general factory automation and process control equipment such as programmable logic controllers (PLCs), I/O peripherals, and computer numerical control (CNC) machines.
The IPS160HF and IPS161HF intelligent power switches integrate a logic interface, driving circuitry, various protection features, and an n-channel power MOSFET output stage. The output stage is internally limited at 2.5A minimum (IPS160HF) and 0.7A (IPS161HF). Both devices withstand an applied supply voltage of up to 65V and integrate active clamp circuitry for handling inductive loads.
Built-in safeguards include ground-disconnect and VCC-disconnect protection, thermal shutdown, under-voltage lock-out, and short-circuit cut-off – designed to protect the IC, the application, and the load against over stress. The cut-off acts after a delay time, which is programmed with an external capacitor, and provides non-dissipative protection that minimizes overheating.
The IPS160HF and IPS161HF are in production now and available in the thermally enhanced PowerSSO12 package.