73K224BL
V.22bis, V.22, V.21, Bell 212A, 103
Single-Chip Modem w/ Integrated Hybrid
DATA SHEET
version is intended for use with 8039/48 or
8031/51 compatible microcontrollers from Intel or
many other manufacturers. The serial interface
mode can be used with other microcontrollers or in
applications where only a limited number of port
lines are available or the application does not lend
itself to a multiplexed address/data interface. The
parallel versions may also be used in the serial
mode, as explained in the data sheet pin
description.
APPLICATIONS INFORMATION
GENERAL CONSIDERATIONS
Figure 5 shows the basic circuit diagram for a
73K224BL modem integrated circuit designed to be
used in conjunction with a control processor, a UART
or RS-232 serial data interface, and a DAA phone line
interface to function as a typical intelligent modem.
The K-Series ICs interface directly with Intel 8048 and
80C51 microprocessors for control and status
monitoring purposes. A typical DAA arrangement is
shown in Figure 5. This diagram is for reference only
and does not represent a production-ready modem
design.
In most applications the controller will monitor the
serial data for commands from the DTE and the
received data for break signals from the far end
modem. In this way, commands to the modem are
sent over the same line as the transmitted data. In
other applications the RS-232 interface handshake
lines are used for modem control.
The 73K224BL is available with two control interface
versions: one for a parallel multiplexed address/data
interface, and one for a serial interface. The parallel
RING DETECT
+5
TX DATA
RX DATA
+
2 M
Ω
1 μF
1
2
3
4
5
6
7
32
31
GND
CLK
RXA
VREF
RESET
N/C
11.0592
30
29
XTL1
XTL2
AD0
AD1
RING
DETECTOR
28
27
8.2 K
0.1 μF
ISET
OH
26
25
24
0.1 μF
AD2
AD3
AD4
AD5
RXCLK
RXD
TXD
HOOK
RELAY
8
9
ADR/DATA BUS
CONTROL
INTERFACE
23
22
21
10
11
12
13
FUSE
CS
+5
AD6
AD7
ALE
EXCLK
TXCLK
INT
600
Ω
μ
C ALE
1
2
3
4
20
19
μ
C
WR
RD
14
15
WR
RD
N/C
μ
C
18
17
TXA1
+5
16
VDD
TXA2
+
600
Ω
RJ - 11
0.033
TYP.
μF
TRANSIENT
SUPPRESSOR
1:1
10 μF
TRANSFORMER
0.1 μF
RXCLK
TXCLK
EXCLK
CHIP SELECT
FIGURE 5: Typical 73K224BL DAA Circuit
Page: 28 of 33
© 2005, 2008 TERIDIAN Semiconductor Corporation
Rev 7.1