Using TSC9402 chip produced by Teledyne Semiconductor, can be made a voltage frequency converter using fewer electronic components.
TSC9402 is able not only to convert the voltage to frequency, but also frequency to voltage (can be used as an extension to a multimeter to measure frequencies).
Output voltage, U0, is calculated using the formula: U0-Urefx (C1+ 12pF) R2x fin [V]. Because the value of capacity is often greater than the value of 12 pF taken into this formula , the formula does not provide an absolute value. Circuit has a frequency range starting from DC up to 10 kHz.
At 10 kHz, the formula will result in a value of 3.4 V. The current that flows through the circuit does not exceed 1 mA.