WE866 HW User Guide
1VV0301330 Rev. 3
Page
21
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54
2018-03-13
4.3.2.
Power Supply PCB layout Guidelines
As seen on the electrical design guidelines, the power supply shall have a low-
ESR capacitor on its output, to cut the current peaks, and a protection diode
on its input, to protect the VBATT pins from polarity inversion. The placement
of these components is crucial to ensure the correct working of the circuitry. A
misplaced component can be useless, or even detrimental to the power supply
performances.
The low-ESR, bypass capacitor must be placed close to the WE866
VBATT pads, or close to the inductor if a switching regulator is used.
The protection diode must be placed close to the input power connector.
The pcb power traces must be wide enough to ensure negligible voltage
drop even at the highest rated current consumption for the WE866.
Use of a good, common ground plane is recommended.
VDD Power Output
A regulated 1.85V supply voltage is provided on pin G6 of the WE866 module. Please note
that this voltage has the sole purpose to be a reference, e.g. for external voltage translators.
No external devices must be powered from this voltage.
Both three-cell Ni/Cd or Ni/MH 3.6V batteries, and 4V Pb batteries, can
feature maximum voltages above the maximum allowed VBATT for the
WE866, which is 4.5V. For this reason, they must not be directly
connected to the module. Only Li-Ion types are recommended for
direct connection.
Summary of Contents for WE866
Page 1: ...04 2016 Mod 0805 2016 08 Rev 5 WE866 HW User Guide 1VV0301330 Rev 3 2018 03 13 13...
Page 10: ...WE866 HW User Guide 1VV0301330 Rev 3 Page 10 of 54 2018 03 13 Related Documents...
Page 33: ...WE866 HW User Guide 1VV0301330 Rev 3 Page 33 of 54 2018 03 13 7 MECHANICAL DESIGN Drawing...
Page 54: ...04 2016 Mod 0805 2016 08 Rev 5...
