73K224L-28IH/F TERIDIAN [Teridian Semiconductor Corporation], 73K224L-28IH/F Datasheet - Page 25

• Manufacturer Part Number: 73K224L-28IH/F
• Description: Single-Chip Modem
• Manufacturer: TERIDIAN [Teridian Semiconductor Corporation]

APPLICATIONS INFORMATION
GENERAL CONSIDERATIONS
Figures 1 and 2 show basic circuit diagrams for
K-Series modem integrated circuits. K-Series products
are 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. Two typical DAA
arrangements are shown: one for a split ±5 or
±12V design and one for a single 5V design. These
diagrams are for reference only and do not represent
production-ready modem designs.
Page: 25 of 31
CA
CB
CC
CD
DA
DD
DB
CF
BA
BB
CONVERTERS
MC145406
RS232
LEVEL
U5, U6
RTS
CTS
DSR
DTR
DCD
TXD
RXD
EXCLK
RXCLK
TXCLK
P1.0
P1.1
P1.2
P1.3
P1.5
P1.6
P3.0
XTL2
N/C
80C51
P1.7
P0.0-7
RESET
XTL1
P3.1
P3.2
ALE
WR
INT
RD
FIGURE 1: Basic Box Modem with Dual-Supply Hybrid
CLK
INT
RD
WR
ALE
CS
39 pF
C14
RESET
XTL1
K-SERIES
11.0592
POWER
FAMILY
MHZ
LOW
Y1
XTL2
©
18 pF
+5V
C13
VREF
GND
ISET
RXA
2005, 2008 TERIDIAN Semiconductor Corporation
VDD
1 µF
TXA
C12
+5V
0.1 µF
2.2M
0.1 µF
R10
C11
C10
0.1 µF
0.1 µF
RXA
TXA
C7
C6
0.1 µF
C9
20K
R6
LM 1458
+
-
300 pF
43.2K
+
C2
R7
22 µF
V+
V–
C8
U1B
K-Series devices are available with two control
interface versions: one for a parallel multiplexed
address/data interface, and one for a serial
interface. The parallel version is intended for use
with 8039/48 or 8031/51 microcontrollers from
Intel or many other manufacturers. The serial
interface 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.
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.
1000 pF
C3
U1A
LM 1458
390 pF
37.4K
475 1%
ZENER
D3, D4
R5
4.7V
C1
R1
+
-
V.22bis, V.22, V.21, Bell 212A, 103
10K
R9
0.033 µF
3.6K
R3
C4
IN914
5.1K
R4
D2
20K
R4
+5V
Q1
DATA SHEET
2N2222A
MIDCOM
671-8005
K1
T1
IN4004
D1
Single-Chip Modem
+5
22K
22K
0.47 µF
R8
250V
C5
4N35
U2
73K224L
Rev 7.1
V250L20
MOV
VR1
T
R