IC references are popular with circuit designers because they are accurate and exhibit low drift. Some of my future columns will cover the three types of IC references: buried zener, bandgap, and XFET ...

Zeners are commonly used as low-current sources for bias voltage functions, but the proper voltage reference can give the same result and with much-lower dissipation and no performance tradeoffs.

Suppose the zener diode on the circuit has a breakdown voltage of 10 V. What are the minimum and maximum zener currents? The applied voltage may vary from 20 to 40 V. Ideally, a zener diode acts like ...