WE866 HW User Guide
1VV0301330 Rev. 3
Page
20
of
54
2018-03-13
4.3.1.1.
+5V Source Power Supply Design Guidelines
Because of the small difference between the input and output voltage, a
switching converter is not the best choice, therefore a low-dropout regulator
is required.
When using a linear regulator, a proper heat sink must be provided in order
to dissipate the power generated.
A low-ESR, bypass capacitor of adequate capacity must be provided in
order to cut the current absorption peaks close to the WE866, 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 WE866 from power polarity inversion.
Guidelines
4.3.1.2.
+12V Source Power Supply Design Guidelines
In this case, better efficiency of switching regulators can be exploited to
generate the required 3.8V
Switching frequencies of 500kHz or above are preferable, because of the
smaller inductor size and the faster transient response.
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 spike protection diode has to be
inserted close to the power input.
A low-ESR, bypass capacitor of adequate capacity must be provided in
order to cut current absorption peaks. 100µF, 10V is usually enough.
A protection diode should be inserted close to the power input, to avoid
damage to the WE866 from polarity inversion. This can be the same diode
used for spike protection.
4.3.1.3.
Battery Source Power Supply Design Guidelines
A single 3.7V Li-Ion cell battery can be used to power the WE866 module.
A low-ESR, bypass capacitor of adequate capacity must be provided in
order to cut current absorption peaks. 100µF, 10V is usually enough.
The WE866 module must be protected from polarity inversion: this can be
done with a protection diode, or by exploiting a suitable battery connector
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...
