User's Manual

GE866-DUAL Hardware User Guide
1VV0301051 Rev. 2 – 2014-04-07 7
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Mod. 0805 2011-07 Rev.2
The electrical design for the Power supply should be made
ensuring it will be capable of a peak current output of at
least 2 A.
6.3. General Design Rules
The principal guidelines for the Power Supply Design embrace
three different design steps:
• The electrical design
• The thermal design
• Thermal PCB layout
6.3.1. Electrical Design Guidelines
The electrical design of the power supply depends strongly on
the power source from which this power is drained. We will
distinguish them into three categories:
• +5V input (typically PC internal regulator output)
• +12V input (typically automotive)
• Battery
6.3.1.1. + 5V input Source Power Supply Design Guidelines
• The desired output for the power supply is 3.8V, hence
there's not a big difference between the input source and
the desired output and 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 GE866-QUAD, 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 should be inserted close to the power
input, in order to save the GE866-QUAD from power polarity
inversion.