LM2917M-8/NOPB (TEXAS INSTRUMENTS)

The LM2917M-8/NOPB is a Frequency to Voltage Converter with a high gain op amp/comparator designed to operate a relay, lamp or other load when the input frequency reaches or exceeds a selected rate. The tachometer uses a charge pump technique and offers frequency doubling for low ripple, full input protection and its output swings to ground for a zero frequency input. The op-amp/comparator is fully compatible with the tachometer and has a floating transistor as its output. This feature allows either a ground or supply referred load of up to 50mA. The two basic configurations offered include an 8-pin device with an input and an internal connection between the tachometer output and the op-amp non-inverting input. Both of these configurations are available with an active shunt regulator connected across the power leads. The regulator clamps the supply such that stable frequency to voltage and frequency to current operations are possible with any supply voltage and a suitable resistor.