Specifications

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possible in order to reduce costs on a possible production version of this device,
low cost regulators would be ideal.
The last requirement is one of temperature resilience. Given the wide variety of
temperatures experienced in an automotive application, the regulators must be
able to withstand such stresses. Assuming winter in the coldest climates, the
minimum temperature should be -40° C. If a vehicle parked outside in the hottest
of summers is assumed, the upper bound of the temperature range should be
74° C.
While the temperature requirement is stated, it should also be taken into account
whether the temperature rating of each regulator is for storage or for operation.
Since the device may be stored in a vehicle, both scenarios may require the
forementioned temperature range to be met.
Figure 2.3.1-1: Basic flowchart of voltage regulator function
2.3.2 Zener-Diode Based Regulation
The first option is one of the simplest. It takes advantage of the properties of the
Zener diode in order to produce an output of constant voltage. Essentially, the
diode would be placed in parallel with the load (output), thus providing the load
with a constant voltage provided the diode is chosen appropriately with respect to
its breakdown voltage. This configuration can be seen in Figure 2.3.2-1.
Figure 2.3.2-1: The configuration of the Zener-diode based voltage regulator
circuit is seen here. Reproduced with permission from http://www.reuk.co.uk/.
The advantages of this circuit are that it is cheap and simple to implement. In
addition, it can be customized to a variety of voltage levels by simply changing