# Buffer **A gate that acts as an electrical amplifier between circuits.** ![[Buffer.svg|200]] Buffers isolate their input and output circuits and also improves voltage and current levels so they stay within range for logical circuits. ## 3-state buffer A *3-state buffer* is a buffer with an additional input control line that enables or disables it. | EN | IN | OUT | |:---:|:---:|:---:| | $0$ | $\times$ | $Z$ | | $1$ | $0$ | $0$ | | $1$ | $1$ | $1$ | ![[3StateBuffer.svg|350]] When disabled, a 3-state buffer outputs a high impedance state.