User's Manual

UE866 HARDWARE USER GUIDE 1vv0301157 Rev.7 • 2015-04-17 17 of 68
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4 POWER SUPPLY
The power supply circuitry and board layout are a very important part in the full product design and
they strongly reflect on the product overall performances, hence read carefully the requirements and
the guidelines that will follow for a proper design.
4.1 Power Supply Requirements
The external power supply must be connected to VBATT & VBATT_PA signals and must fulfil the
following requirements:
Power Supply
Value
Nominal Supply Voltage
3.8V
Normal Operating Voltage Range
3.40 V÷ 4.20 V
Extended Operating Voltage Range
3.10 V÷ 4.50 V
NOTE:
The Operating Voltage Range MUST never be exceeded; care must be taken
when designing the application’s power supply section to avoid having an
excessive voltage drop.
If the voltage drop is exceeding the limits it could cause a Power Off of the
module.
The Power supply must be higher than 3.22 V to power on the module
Overshoot voltage (regarding MAX Extended Operating Voltage) and drop in
voltage (regarding MIN Extended Operating Voltage) MUST never be
exceeded;
The “Extended Operating Voltage Range” can be used only with completely
assumption and application of the HW User guide suggestions.