07 May 2010
Intelligent power switch
Power semiconductor specialist, STMicroelectronics has introduced an intelligent power switch (IPS) for use in industrial controls. It is designed to provide improved accuracy to minimise energy losses and prevent system errors when faults occur.
This was achieved using ST's latest generation VIPower technology, which it says allows a low overload current limit to maintain stable power conditions while the system is recovering.
By providing an integrated solution for two output channels, the VNI2140J also simplifies design, enhances reliability, and saves pc-board space in equipment such as programmable logic controllers (PLCs), peripheral I/O, and industrial process controls.
The two-channel IC has a 6 x 5mm footprint and integrates logic, driver circuitry, power stage, protection, and diagnostic functions. The chip's inputs are 3.3V TTL/CMOS compatible; its outputs are connected in the high-side configuration; and two independent resistive, inductive or capacitive loads can be driven.
The chip's built-in shorted-load protection with independent active current limitation for each channel is designed to prevent load faults from pulling down the system power supply.
If either channel becomes overloaded that channel is turned off independently while the other continues operating normally, and it is restarted automatically when the junction temperature has returned to normal.
If both channels are overloaded, they are restarted non-simultaneously to avoid drawing high peak currents from the power supply. Other features include protection against loss of ground, as well as diagnostics such as open-load detection in the OFF state.