The output voltage of the Zener reference diode is set at approximately 6.9 V and requires a high voltage supply. The band-gap voltage reference diode has a significant advantage over the Zener reference diode in that it is capable of a lower minimum operating current and has a sharper knee.

The band-gap reference relies on matched transistors and is therefore easily integrated along with biasing, buffer and amplifier circuitry to give a complete reference diode.

The LM285/LM385 series are examples of micropower two-terminal band-gap voltage reference diodes. These devices are designed to operate over a wide current range of 10 μA to 20 mA.

The features of these devices include exceptionally low dynamic impedance, low noise, and stable operation over time and temperature. The low operating current make these devices suitable for micropower circuitry, such as portable instrumentation, regulators and other analog circuitry that requires extended battery life.

  Many types of two-terminal 1.2 V voltage reference diodes offer the same performance, but are not all directly interchangeable. Minor differences in regulation voltage and in allowable or required capacitive loading may affect a circuit.