Description
The device iC-WD is a monolithic switching regulator with two downstream 5 V resp. 3.3 V linear regulators. In view of the high efficiency of the down converter for an input voltage range of 8 to 36 V, the iC-WD family is well-suited for industrial applications which require a stabilised 5 V resp. 3.3 V power supply with minimal power dissipation and few components. Switching transistor, free-wheeling diode and oscillator are integrated, limiting the necessary external elements for the switching regulator to the inductor, the back-up capacitor and one resistor. This resistor determines the regulator’s cut-off current and thus its efficiency in the par ticular application at hand. The downstream linear regulators feature a low residual ripple even with relatively small smoothing capacitors in the μF range. The output voltages have an internal reference and are specified ±5% in the entire operating and temperature range. The use of two mutually independent linear regulators makes it possible to isolate the voltage supply of sensitive analogue circuits or sensors from the supply for digital and driver devices. The chip temperature and the output voltages are monitored. A fault is signalled via the current-limited open-collector output NER, for example by an LED display or a logical link with other error signals from the system. In the event of over temperature, the switching regulator is disabled to reduce the power dissipation of the chip.
Features