LM2907 Frequency to Voltage Converter

Description

Description The LM2907 is a monolithic frequency to voltage converters with a high gain op-amp/comparator designed to operate a relay, lamp, or another 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 in two versions (LM2907-8, LM2917-8), and its output swings to the ground for a zero frequency input. LM2907 Pinout LM2907 Pin Configuration Pin No Description 1 Input Frequency 2 Charge Pump Pin 3 Input Bias Current 4 Output Voltage 5 Sink Current 6 Positive Voltage 7 Input Bias Current 8 Input Signal Ground Pin LM2907 Features Ground referenced tachometer input interfaces directly with variable reluctance magnetic pickups Op amp/comparator has floating transistor output 50 mA sink or source to operate relays, solenoids, meters, or LEDs Frequency doubling for low ripple Tachometer has built-in hysteresis with either differential input or ground referenced input Built-in Zener on LM2917 Ground referenced tachometer is fully protected from damage due to swings above VCC and below ground Application Over/under speed sensing Frequency to voltage conversion (tachometer) Speedometers Breaker point dwell meters Hand-held tachometer Speed governors Cruise control Automotive door lock control Clutch control Horn control Touch or sound switches