User's Manual

CE910-DUAL Hardware User Guide

1vv0301010 Rev .0 – 2012-07-10

 A protection diode must be inserted close to the power input in order to save the

CE910-DUAL from power polarity inversion. This can be the same diode as for

spike protection.

An example of switching regulator with 12V input is in the schematic below:

5.2.4. 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. A single 3.7V lithium-ion cell battery type is ideal to supply power to the Telit CE910-

DUAL module.

WARNING:

The three battery cells (Ni/Cd or Ni/MH 3.6V nom. battery types or 4V PB types) MUST

NOT be used directly because their maximum voltage can rise over the absolute maximum

voltage for the CE910-DUAL and cause damage. USE only Li-Ion battery types.

 A bypass low (usually a 100uF tantalum) ESR capacitor with adequate capacity

must be provided in order to cut the current absorption peaks.

 Make sure the low ESR capacitor (usually a tantalum) is rated at least 10V.

 A protection diode must be inserted close to the power input in order to protect

the CE910-DUAL module from power polarity inversions when connecting the

battery.

 The battery capacity must be at least 500mAh in order to withstand the current

peaks of 1A. The suggested battery capacity is from 500mAh to 1000mAh.

5.2.5. Thermal Design Guidelines

The thermal design for the power supply heat sink must be done with the following

specifications: