with zener diode parallel to the load.

Voltage regulator with zener diode parallel to the load are generally used when is necessary to obtain a reduced voltage of moderate power from the main supply line.

Since it is an analog regulation it has the property to give a stable voltage, without parasitic fluctuation and with limited noise levels. The very low energetic efficiency makes it useful mainly when small current are required.

Data input

Max supply voltage . . . **V**_{MAX}

V

Min supply voltage . . . **V**_{MIN}

V

Stabilized voltage required . . . **V**_{Z}

V

Maximum required current . . . **I**_{OUT}

Results.

**Dropping resistance . . . R**

ohm

Maximum power dissipated by resistor . . . **W**_{R}

W

Maximum power dissipated by zener . . . **W**_{Z}

W

Maximum voltage drop . . . V_{R} MAX

V

Minimum voltage drop . . . V_{R} MIN

V

**Max power dissipated by resistor W _{R}.**

It refers to the condition in which supply voltage is at the maximum value (

**Max power dissipated by zener diode W _{Z}.**

It refers to the condition in which fails the load and the supply voltage is at the maximum value (

**Power of the zener.**

The zener diode to be installed should be selected with a power at least equal to
**W**_{Z}.

**Zener temperature coefficient.**

As temperature increases, at same current flowing through the zener, the zener voltage
increases if V_{Z} > 5V and it decreases if V_{Z} < 5V.
So the temperature coefficient can, be negative or positive.

A diode with a V_{Z} near 5V has a reduced temperature coefficient.

Instructions

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Notices