User's Manual

GE/GC864-QUAD V2 and GE864-GPS Hardware User Guide
1vv0300915 Rev.2 – 2011-06-15
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights
Reserved. Page 40 of 97
efficiency especially with the 2A peak current load
represented by the module.
• 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 that the switching
frequency could also generate EMC interferences.
• As far as car PB battery, the input voltage can rise
up to 15.8V. This must 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 100µF tantalum capacitor is typically used.
• Make sure the low ESR capacitor on the power supply
output (usually a tantalum one) is rated at least 10V.
• As far as car applications, a spike protection diode
must be inserted close to the power input, in order to
clean the supply from spikes.
• A protection diode can be inserted close to the power
input, in order to save the module from power polarity
inversion. This can be the same diode used for spike
protection.
An example of switching regulator with 12V input is in the
schematic below (split in 2 parts):