Free Circuit Diagram

Using VFC110 chip, we can build a high frequency voltage-to-frequency converter. The features of this chip include the capability of high frequency operation, disable function, and an on-board precision 5V reference. This precision reference can be used to provide reference for offsetting the VFC transfer function, as well as provide transducer or bridge excitation. As [...]

Using LM231/331 chip, we can build a low-cost voltage-to-frequency converter, ideal for analog-to-digital conversion, frequency-to-voltage conversion, long-term integration, linear frequency modulation-demodulation, and many other functions.  When it’s used as voltage-to-frequency converter, the output will be a pulse train with frequency linearly equal to the applied input voltage. For higher level of accuracy against temperature drift, [...]

Although this circuit use more resistor components than in basic standard three op-amps instrumentation amplifier circuit, this circuit has the benefit of easy gain adjustment with only one control resistor. Because the easy gain adjustment feature, this circuit topology has been used inside a single chip instrumentation amplifier ic. The figure below shows the schematic [...]

For standard instrumentation amplifier, a three op-amps instrumentation amplifier circuit is common, but if you need smaller component count and lower cost, you can use just two op-amps for the same function: a high impedance and good CMRR for sensor pre-amplification and buffering. Here is the circuit’s schematic duiagram:

A two-op-amp instrumentation amplifier can also be [...]

Using LMV721/722 or any other high impedance op-amps, you can build an instrumentation amplifier using standard three op-amps instrumentation amplifier circuit. The figure below shows the circuit’s schematic diagram.

The final stage of this instrumentation amplifier is a differential-input, differential-output amplifier, with two voltage followers feed its inputs. These two voltage followers assure that the input [...]