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)
Applications
• Over- and Under-Speed Sensing
• Frequency-to-Voltage Conversion (Tachometer)
• Speedometers
• Breaker Point Dwell Meters
• Hand-Held Tachometers
• Speed Governors
• Cruise Control
• Automotive Door Lock Control
• Clutch Control
• Horn Control
• Touch or Sound Switches
