AN2161 - PSoC® 1 Analog - Voltage-to-Frequency Converter

Voltage-to-frequency (V/F) converters are widely used in industrial electronics, frequency-shift keying modulators, phase-locked loop systems, analog-to-digital converters, isolation amplifiers, etc. Even though these converters are produced as standalone devices, they still require several external components and are relatively expensive in comparison to modern low-cost analog integrated circuits. The PSoC allows the designer to build the V/F using only one continues continuous time (CT) analog block (configured as schmitt trigger) and one switched capacitor (SC) analog block (configured as integrator), without any external analog components. All digital blocks, and the CPU, are at user disposal. The designer will get a useful device function with virtually no additional cost or extra components. Moreover, the proposed V/F converter produces both meander and symmetric sawtooth signals, which are useful for some applications such as analog PWM modulators and capacitance meters.