User's Manual

GE864
GE864GE864
GE864-
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-QUAD V2 / GE864
QUAD V2 / GE864QUAD V2 / GE864
QUAD V2 / GE864-
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-DUAL V2 Hardware User Guide
DUAL V2 Hardware User GuideDUAL V2 Hardware User Guide
DUAL V2 Hardware User Guide
1vv0300875 Rev.1 – 2010-03-29
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved. Page 26 of 73
6.2.1.1.
6.2.1.1.6.2.1.1.
6.2.1.1. +
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+5V input Source Power Supply Design Guidelines
5V input Source Power Supply Design Guidelines5V input Source Power Supply Design Guidelines
5V input Source Power Supply Design Guidelines
• The desired output for the power supply is 3.8V, hence there is no big
difference between the input source and the desired output. A linear
regulator can be used. A switching power supply will not be suited
because of the low drop out requirements.
• When using a linear regulator, a proper heat sink shall be provided in
order to dissipate the power generated.
• A Bypass low ESR capacitor of adequate capacity must be provided in
order to cut the current absorption peaks close to the GE864-QUAD V2 /
GE864-DUAL V2, a 100µF 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.
• A protection diode can be inserted close to the power input, in order to
save the GE864-QUAD V2 / GE864-DUAL V2 from power polarity inversion.
An example of linear regulator with 5V input is: