1. Key Impedance Characteristics: The most important properties of a voltage follower are:
• Very High Input Impedance: It draws almost zero current from the source circuit.
• Very Low Output Impedance: It can provide significant current to the load circuit without dropping its output voltage.
2. The Role of an Isolator (Buffer): Because of these impedance properties, the voltage follower acts as an Isolator. It prevents a "Loading Effect" where a low-impedance load might pull down the voltage of a high-impedance source. It "buffers" or "isolates" the source from the load, ensuring the signal voltage remains accurate while allowing the load to draw the current it needs.
3. Why not other options?:
• Switch: It is a linear amplifier, not a binary on/off device.
• Regulator: It maintains the input voltage at the output, but it doesn't regulate a varying power supply into a fixed DC level like a Zener or an IC regulator.
• Compensator: This usually refers to phase-lead or phase-lag networks used in control systems.