Specifications

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Figure 2.2.3.2-1 TI EZ430-RF2500, reprinted with permission from Texas
Instruments
2.2.4 System Logic Conclusions
Based upon a thorough evaluation of potential solutions for programmable
system logic, our conclusion is that a Microcontroller would be the most optimum
solution for our design. Compared to either an FPGA or a custom ASIC, the
Microcontroller offers the lowest possible NRE, while maintaining a high level of
performance and programmable flexibility. Utilizing a Microcontroller with a
particular subset of integrated components would allow us to reduce the duration
of both the software and hardware development cycles for this design
2.3 Voltage Regulator
The power requirements of both the portable and car-mounted units will be
determined by the various sub components of each major component. However,
there are basic specifications which will determine the design and selection of
components for the power system. One of the needs of this system will be in
voltage regulation.
One assumption of the design is that the input power will be at least roughly
regulated. As the primary source of power for the devices will be from the 12V
rail of a car’s electrical system, the power should be somewhat regulated.
However, it would be poor design to depend heavily on this. Not all vehicles
output a constant and regulated 12V at all times. A vehicle in good condition will
have a nominal 12V output from the battery. However, a weak battery, defective
fuses, weak alternator, corroded electrical system, or several other concerns, can
create conditions of fluctuating voltage. This can often be seen on a vehicle with
a weak battery; the interior lights will flicker as the electrical system is essentially