HE910 Hardware User Guide
1VV0300925 Rev. 32
Page
46
of
111
2019-11-25
An example of switching regulator with 12V input is in the below schematic:
Figure 5-2 switching regulator
5.3.1.3.
Battery Source Power Supply Design Guidelines
The desired nominal output for the power supply is 3.8V and the maximum voltage
allowed is 4.2V, hence a single 3.7V Li-Ion cel power to the Telit HE910 module.l battery
type is suited for supplying the power to the Telit HE910 module.
Warning
The three cells Ni/Cd or Ni/MH 3,6 V Nom. battery types or 4V PB
types MUST NOT BE USED DIRECTLY since their maximum voltage
can rise over the absolute maximum voltage for the HE910 and
damage it.
NOTE:
DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly
connected with HE910. Their use can lead to overvoltage on the
HE910 and damage it. USE ONLY Li-Ion battery types.
•
A Bypass low ESR capacitor of adequate capacity must be provided in order to cut
the current absorption peaks, a 100μF tantalum capacitor is usually suited.
•
Make sure the low ESR capacitor (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
HE910 from power polarity inversion. Otherwise the battery connector should be
done in a way to avoid polarity inversions when connecting the battery.
•
The battery capacity must be at least 500mAh in order to withstand the current
peaks of 2A; the suggested capacity is from 500mAh to 1000mAh.
Summary of Contents for HE910
Page 1: ... 01 2017 Mod 0805 2017 01 Rev 6 HE910 HW User Guide 1VV0300925 Rev 32 2019 11 25 ...
Page 40: ...HE910 Hardware User Guide 1VV0300925 Rev 32 Page 40 of 111 2019 11 25 ...
Page 71: ...HE910 Hardware User Guide 1VV0300925 Rev 32 Page 71 of 111 2019 11 25 ...
Page 111: ... 01 2017 Mod 0805 2017 01 Rev 6 ...
