cxa3003r Sony Electronics, cxa3003r Datasheet - Page 31

• Manufacturer Part Number: cxa3003r
• Description: Baseband Analog Processing Ic For Dual-mode Cdma/fm Cellular Phone
• Manufacturer: Sony Electronics

CXA3003R
13. Power Supply Considerations, Grounding, and Decoupling
The CXA3003R is targeted for use in battery operated CDMA/FM portable cellular telephones. As such,
the device has been designed to operate from a regulated 3.3 V power supply. The use of multiple
voltage regulators is recommended throughout the telephone, but the CXA3003R should be powered
from only one dedicated voltage regulator. Individual voltage regulators are usually assigned to the major
circuit subsections within the (i.e. receive RF, transmit RF, power amplifier, CXA3003R, etc.) to reduce
the possibility of signals from one subsection interfering with or distorting signals from another subsection.
The voltage regulator used in telephone for the CXA3003R should be a linear voltage regulator, not a
switching regulator. This is to keep power supply noise on the CXA3003R power inputs as low as
possible. The recommended power supply voltage range of the CXA3003R is from 3.13 to 3.47 V (3.3±5
%). It is recommended that a ±2 % accurate regulator be used so that the proper output voltage can be
maintained over the temperature range of the telephone and over the power supply current range of the
CXA3003R.
Power supply decoupling around the CXA3003R is done with 0.01 µF ceramic chip capacitors on each
VDD pin. The capacitors are located as close to the pins as possible to minimize series inductance in the
connection to the pin. The use of additional 0.001 µF decoupling capacitors in parallel with the 0.01 µF
capacitors is recommended to further reduce high frequency noise on the power supply inputs to the
CXA3003R.
Although the CXA3003R has both analog and digital circuits and separate digital power and ground pins
a single ground plane is recommended. The ground plane must overlap the footprint of the CXA3003R
as much as possible. ALL CXA3003R ground pins must be connected to the same analog ground plane.
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