HGSEMI LM2917MT-14/TR

The LM2907/LM2917 series are monolithic frequency-to-voltage converters with high-gain op-amp/comparators, designed to operate relays, lamps, or other loads when the input frequency reaches or exceeds a selected rate. The built-in tachometer uses charge pump technology with frequency doubling for low ripple; the comparator features 30mV of hysteresis, which can be used to suppress external interference. The op-amp/comparator is fully compatible with the tachometer and features a floating transistor as its output, allowing grounding or sourcing loads of up to 50mA. The collector may be above VCC, with a maximum VCE of 28V. The general-purpose configuration provides differential tachometer inputs and uncommitted op-amp inputs. In this version, the tachometer input may float, and the op-amp is suitable for active filter conditioning of the tachometer output. This configuration can be used as an active shunt regulator connected via the supply line. The regulator clamps the supply, enabling stable frequency-to-voltage and frequency-to-current operation with any supply voltage and an appropriate resistor. The LM2907/LM2917 is available in DIP14, SOP14, TSSOP14, DIP8, and SOP8 packages.

• Single RC network for frequency multiplication with LM2907/LM2917.
• Ground-referenced tachometer (frequency) input directly accessible from input pin.
• Op-amp/comparator with floating transistor output.
• Up to 50mA output current for driving transistor switches, LEDs, etc.
• On-chip tachometer uses charge pump technology with frequency multiplication for low ripple.
• Comparator hysteresis of 30mV for external noise suppression.
• Output voltage proportional to input frequency, typical linearity of ±0.3%.
• Protected against damage from input signals above VCC or below ground.
• LM2907 output voltage at zero frequency input self-adjustable via external circuitry.
• Output can drive relays, indicators, and other loads when input frequency reaches or exceeds a given threshold.
• Zero-frequency input determines output swing to ground.
• Easy to use: VOUT = fIN × VCC × R × C
• Single RC network for frequency doubling.
• On-chip Zener regulator for precise and stable frequency-to-voltage or frequency-to-current conversion (LM2917).

• Speed Measurement
• Frequency-to-voltage conversion (tachometer)
• Speedometer
• Handheld tachometer
• Speed governor
• Cruise control
• Automotive door lock control
• Clutch control
• Horn control
• Touch or sound switch