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U101
MIC
Speaker
A,B,C Serial Port
Receiver
VOUTNOR P/N
Phone
Jack
VINAUX P/N
LOUD
AIN1P/1N
AOUT1P/1N
AOUT3P
AOUT3N
AIN2P/2N
VOUTAUX P
PJ_FUNC_SEL
Voice
Data
Analogue
Switch
VINNOR P/N
TX/RX
Figure 5.9. Audio system block diagram
The U201 is a complete mixed-signal baseband processor that combines all of the data converters and power supply regulators
required for a GSM 900 /GSM 850 /DCS 1800 / PCS 1900 mobile on a single device, including HSCSD and GPRS. The U201
auxiliary section provides a voltage reference, an automatic frequency control DAC, an auxiliary ADC, and light controllers.
It has two differential output ports, two differential input ports, and a buzzer output. Voiceband normal output is used in normal
receiver mode. Voiceband auxiliary output is used in earpiece receiver mode. Buzzer output signal via a melody IC is used in
loud-speak mode. The voiceband input is used for microphone connection and the auxiliary input used for external (Handsfree)
microphone connection.
5.3.1. Voiceband Baseband Codec
Chipset
U201
Package
148-Ball LFBGA
Feature
■
Baseband Transmit Section
GMSK Modulator
I-channel & Q-channel Transmit DACs and Filters
Power Ramping DAC
■
Baseband Receive Section
I-channel and Q-channel Receive ADCs and Filters
■
Auxiliary Section
Voltage Reference
Automatic Frequency Control DAC
Auxiliary ADC
Light Controllers
■
Audio Section
8 kHz & 16 kHz Voiceband Codec
48 kHz Monophonic DAC
Power Amplifiers
■
Power Management Section
Voltage Regulators
Battery Charger
Battery Protection
■
Digital Processor Interface
Control, Baseband, and Audio Serial Ports
Interrupt Logic
5.3. Audio System
MA3
U201