A voltage follower, also known as a buffer amplifier, is an electronic circuit configuration where the output voltage directly follows the input voltage. It is typically implemented using an operational amplifier (op-amp) with its output connected to its inverting input, and the input signal applied to the non-inverting input. This configuration provides a unity gain (gain of 1), meaning the output voltage is the same as the input voltage. The primary function of a voltage follower is to provide high input impedance and low output impedance, which makes it ideal for impedance matching between circuits.
Voltage follower refers to an amplifier circuit where the output voltage is the same as the input voltage, maintaining the voltage level while providing the ability to drive heavier loads. This is achieved using an op-amp in a specific configuration where the op-amp’s gain is unity. The voltage follower does not amplify the voltage but serves as a buffer that isolates different stages of a circuit, preventing the loading of the source and allowing the subsequent stage to operate correctly.
A current voltage follower, or simply a voltage follower, is primarily concerned with maintaining the voltage level of the input signal while supplying sufficient current to the load. The term “current voltage follower” emphasizes the circuit’s ability to provide the necessary current to drive the load without altering the input voltage. This is particularly useful when the source cannot supply enough current for the load directly, ensuring that the input signal is not distorted or attenuated due to the loading effect.
The purpose of a voltage buffer, which is another name for a voltage follower, is to provide impedance matching between different stages of a circuit. By presenting a high input impedance and a low output impedance, the voltage buffer prevents the previous stage from being loaded down and ensures that the following stage receives a stable and undistorted signal. This is essential in many applications, such as analog signal processing and data acquisition systems, where signal integrity must be maintained across multiple stages of circuitry.
A voltage follower is a special case of a non-inverting amplifier where the gain is set to one. In a non-inverting amplifier, the output signal is in phase with the input signal, and the gain is determined by the ratio of external resistors. In the case of a voltage follower, the external feedback resistor network is configured to provide a gain of unity. This specific setup retains all the benefits of a non-inverting amplifier, such as high input impedance and low output impedance, but with a gain of one, making it particularly useful for buffering and impedance matching applications.