MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Order this document
by MC145442/D
Single-Chip 300-Baud Modem
The MC145442 and MC145443 silicon–gate CMOS single–chip low–speed
modems contain a complete frequency shift keying (FSK) modulator, demodu-
lator, and filter. These devices are with CCITT V.21 (MC145442) and Bell 103
(MC145443) specifications. Both devices provide full–duplex or half–duplex
300–baud data communication over a pair of telephone lines. They also include
a carrier detect circuit for the demodulator section and a duplexer circuit for
direct operation on a telephone line through a simple transformer.
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MC145442 Compatible with CCITT V.21
MC145443 Compatible with Bell 103
Low–Band and High–Band Band–Pass Filters On–Chip
Simplex, Half–Duplex, and Full–Duplex Operation
Originate and Answer Mode
Analog Loopback Configuration for Self Test
Hybrid Network Function On–Chip
Carrier Detect Circuit On–Chip
Adjustable Transmit Level and CD Delay Timing
On–Chip Crystal Oscillator (3.579 MHz)
Single + 5 V Power Supply Operation
Internal Mid–Supply Generator
Power–Down Mode
Pin Compatible with MM74HC943
Capable of Driving – 9 dBm into a 600
Ω
Load
MC145442
MC145443
20
1
P SUFFIX
PLASTIC DIP
CASE 738
20
1
DW SUFFIX
SOG PACKAGE
CASE 751D
ORDERING INFORMATION
MC145442P
MC145443P
Plastic DIP
Plastic DIP
MC145442DW SOG Package
MC145443DW SOG Package
PIN ASSIGNMENT
DSI
LB
CD
CDT
RxD
VDD
CDA
Xout
Xin
FB
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
TLA
VAG
Exl
TxA
RxA1
RxA2
SQT
MODE
VSS
TxD
REV 1
8/95
©
Motorola, Inc. 1995
MOTOROLA
MC145442•MC145443
1