Frequency to Voltage Converter
Description
LM2907-N, LM2917-N
www.
ti.
com
SNAS555C – JUNE 2000 – REVISED MARCH 2013
LM2907/LM2917 Frequency to Voltage Converter
Check for Samples: LM2907-N, LM2917-N
FEATURES
1
•2 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 • ±0.
3% Linearity Typical • Ground Referenced Tachometer is Fully Protected From Damage Due to Swings Above VCC and Below Ground
APPLICATIONS
• 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
DESCRIPTION
The LM2907, LM2917 series are monolithic frequency to voltage converters 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 in two versions (LM2907-8, LM2917-8) 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 50 mA.
The collector may be taken above VCC up to a maximum VCE of 28V.
The two basic configurations offered include an 8-pin device with a ground referenced tachometer input and an internal connection between the tachometer output and the op amp non-inverting input.
This version is well suited for single speed or frequency switching or fully buffered frequency to voltage conversion applications.
The more versatile configurat...
Similar Datasheet
