Tait TM8100 mobiles - Page 235

TM8100/TM8200 Service Manual Frequency Synthesizer Fault Finding 235
© Tait Electronics Limited November 2007
Figure 9.16 Test and measurement points the FCL circuitry
RF ANALOG CLOCK DIGITAL
SIGNAL TYPES
PSU
LPF
MIXER
VCXO
TCXO
MODULATOR BUFFER AMPLIFIER
AGND
DIGITAL
BOARD
CDC VCXO MOD
SYN CDC FCL
BUFFER AMPLIFIER
INTERFACE
CIRCUITRY
RECEIVER
FCL CIRCUITRY
+3V0 AN
SUPPLY
C536
R541
VCXO OUTPUT
AT C536
VCXO OUTPUT
AT C536
PLL
SYN RX OSC
C510
TP504
FEEDBACK
SIGNAL
SYN DIG FREF
TCXO OUTPUT
VCXO OUTPUT
AT R522
(PIN 1 OF IC501)
VCXO OUTPUT
AT R522
(PIN 1 OF IC501)
LO INPUT
AT R521
(PIN 4 OF IC501)
LO INPUT
AT R521
(PIN 4 OF IC501)
TP502
DIFFERENCE
FREQUENCY
TP500 TP501
DAC
ADC
CODEC 2
LOOP
VOLTAGE
÷ 4
LPF
shaded area is A4 band only
LPF
SYN
LO INPUT
AT R521
(PIN 4 OF IC501)
LO INPUT
AT R521
(PIN 4 OF IC501)
TP5TP502
÷ 4
LPF
hdd i A b d l