LM2907-N, LM2917-N
www.ti.com
SNAS555C – JUNE 2000 – REVISED MARCH 2013
LM2907/LM2917 Frequency to Voltage Converter
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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...