GE866-QUAD Hardware User Guide
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Page 31 of 82
Mod. 0805 2011-07 Rev.2
An example of linear regulator with 5V input is:
6.3.1.2.
+ 12V input Source Power Supply Design Guidelines
•
The desired output for the power supply is 3.8V, hence due to the big difference
between the input source and the desired output, a linear regulator is not suited
and shall not be used. A switching power supply will be preferable because of its
better efficiency especially with the 2A peak current load represented by the
GE866-QUAD.
•
When using a switching regulator, a 500kHz or more switching frequency
regulator is preferable because of its smaller inductor size and its faster
transient response. This allows the regulator to respond quickly to the current
peaks absorption.
•
In any case the frequency and Switching design selection is related to the
application to be developed due to the fact the switching frequency could also
generate EMC interferences.
•
For car PB battery the input voltage can rise up to 15,8V and this should be kept
in mind when choosing components: all components in the power supply must
withstand this voltage.
•
A Bypass low ESR capacitor of adequate capacity must be provided in order to
cut the current absorption peaks, a 100
μ
F tantalum capacitor is usually suited.
•
Make sure the low ESR capacitor on the power supply output (usually a tantalum
one) is rated at least 10V.
•
For Car applications a spike protection diode should be inserted close to the
power input, in order to clean the supply from spikes.
•
A protection diode should be inserted close to the power input, in order to save
the GE866-QUAD from power polarity inversion. This can be the same diode as
for spike protection.
