V/F and F/V Converters
1. What are V/F (Voltage-to-Frequency) Converters?
Linearly convert an input DC voltage into a pulse signal of the corresponding frequency. The input voltage range is typically 0-10V, and the output frequency can reach 0-10kHz. Conversion accuracy must be less than 1%. Their core modules include a voltage-to-current converter, a bandgap constant current source, and a multivibrator. Emitter-coupled circuits achieve high linearity (e.g., 10,000:1) and low temperature drift. Due to their strong resistance to interference, these converters are suitable for industrial control, long-distance sensor signal transmission, and wireless/fiber-optic communications.
2. What are F/V (Frequency-to-Voltage) Converters?
Convert an input frequency signal (such as a speed or flow sensor pulse) into a proportional analog voltage output. The typical input frequency range is 0.1mHz to 100kHz, and the output voltage range can reach 0-30Vp-p. Their operating principle is based on charge pump technology: the input frequency drives the charging and discharging of a timing capacitor, and the resulting average current is converted to a DC voltage via a load resistor. This device can directly display physical quantities (such as speed), simplifying on-site commissioning.
3. What are the Core Technologies and Devices of V/F and F/V Converters?
Implementation Options: Two mainstream types are available: a multivibrator (simple and low-cost) and a charge balance (high-precision, supports negative inputs).
Typical Chips: The AD650, for example, supports bidirectional conversion (V/F and F/V) with a nonlinearity of less than 0.07% at a full frequency of 1MHz, making it suitable for precision instruments and long-distance transmission systems.
3. What are the Core Application Areas of V/F and F/V Converters?
Industrial Control: Converts analog sensor signals (such as temperature and pressure) into a frequency for transmission, improving immunity to electromagnetic interference.
Power Systems: Monitors grid frequency and converts it into a voltage signal for motor speed regulation and energy management.
Measuring Instruments: Enables analog reading of digital frequency meters, tachometers, and other devices.
High-Frequency Applications: Uses an M3C frequency-switching valve or dedicated ICs (such as the LM331) to handle high-power/high-frequency signal conversion.