User's Manual

CE910-DUAL Hardware User Guide
1vv0301010 Rev .0 – 2012-07-10
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved. Page 27 of 63
Max Power Mode 750(TBD) CDMA 1x call
(*
1
)The off current is the total supply current from the main battery with the XO regulator ON,
19.2MHz XO ON and others are OFF.
(*
2
) Standby current consumption depends on network configuration or module configuration.
NOTE:
The Operating Voltage Range MUST never be exceeded. Special care must be taken in order
to fulfill min/max supply voltage requirement.
TIP:
The electrical design for the power supply should be made ensuring it will be capable of a
peak current output of at least 1A.
5.2. General Design Rules
The principal guidelines for the Power Supply Design embrace three different design steps:
 the electrical design
 the thermal design
 the PCB layout
5.2.1. Electrical Design Guidelines
The electrical design of the power supply depends strongly on the power source where this
power is drained. We will distinguish them into three categories:
 +5V input (typically PC internal regulator output)
 +12V input (typically automotive)
 Battery
5.2.2. + 5V Input Source Power Supply Design Guidelines
 The desired output for the power supply is 3.8V, hence there is not a big
difference between the input source and the desired output so a linear regulator
can be used. A switching power supply will not be suitable because of the low
drop-out requirements.
 When using a linear regulator, a proper heat sink must 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 CE910-DUAL. A 100μF tantalum
capacitor is usually suited.