MC145446A Datasheet, PDF (2/14 Pages) Motorola, Inc – SINGLE-CHIP 300-BAUD MODEM WITH DTMF TRANSCEIVER

AGC OUT
BLOCK DIAGRAM
FLTC2 FLTC3 FLTC1
DTMF
IN
AGC
RxBO
RxA
RxGC
30 k
+
–
65 k
NOISE
FILTER
NOISE
FILTER
LOW–BAND
BPF
HIGH–BAND
BPF
FREQUENCY
DETECTER
CODE
4 _STATUS
CONVERTER _REGISTER
(DECODER)
TIMING
CIRCUIT
SD/CD/DV
FSK/DTMF LOOPBACK PATH
TxD
FSK
MODULATOR
TLA
LEVEL
CONTROL
DTMF
GENERATOR
LOW–BAND
BPF
MUX
HIGH–BAND
BPF
MUX
MUX/
MIXING
CARRIER/CPT
DETECTOR
CDA
FSK
DEMODULATOR
RxD
DATA
I/O
R/W
MODE CONTROL
LOGIC
CONTROL
SHIFT REGISTER
STATUS
SHIFT REGISTER
SMOOTHING
FILTER
DSI
–1
TxA2
_
+
TxA1
E
POWER–ON ANALOG GROUND
CLOCK
SCK
RESET
GENERATOR
GENERATOR
VCC GND Vref
X1 X2
MC145446A
2
MOTOROLA