The LM2907 and LM2917 devices are monolithic frequency-to-voltage converters with a high gain op amp 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 in two versions (8-pin LM2907 and LM2917), and its output swings to ground for a zero frequency input.

The op amp 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 50 mA. The collector may be taken above VCC up to a maximum VCE of 28 V.

Features:

• Ground Referenced Tachometer Input Interfaces Directly With Variable Reluctance Magnetic Pickups
• Op Amp 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
• ±0.3% Linearity (Typical)
• Ground-Referenced Tachometer is Fully Protected From Damage Due to Swings Above VCC and Below Ground
• Output Swings to Ground For Zero Frequency Input
• Easy to Use×VOUT = fIN × VCC × R1 × C1
• Zener Regulator on Chip allows Accurate and Stable Frequency to Voltage or Current Conversion (LM2917)

Package: PDIP-8

Datasheet: https://www.ti.com/lit/ds/symlink/lm2917-n.pdf?ts=1630410018788&ref_url=https://www.ti.com/product/LM2917-N