ST75185C
Multiple RS-232 drivers and receivers
Features
■
■
Meets and exceeds the requirements of
EIA/TIA-232-E and ITUV.28 standard
Single chip with easy interface between UART
and serial port connector of IBM PC/AT™ and
compatibles
Designed to support data rates up to 120 kbps
Pinout compatible with ST75C185
SO-20
TSSOP20
■
■
Description
The ST75185C contains three drivers and five
receivers. The pinout matches the DB9S
connector design in order to decrease the part
count, reduce the board space required and allow
easy interconnection of the UART and serial port
connector of IBM PC/AT™ and compatibles. The
bipolar circuits and processing of the ST75185C
provides a rugged low-cost solution for this
function at the expense of quiescent power and
external passive components relative to the
ST75C185.
The ST75185C complies with the requirements of
the EIA/TIA 232-E and ITU (formally CCITT) v.28
standards. These standards are for data
interchange between a host computer and
peripheral at signalling rates up to 20 k-bits/s. The
switching speeds of the ST75185C are fast
enough to support rates up to 120 K-bits/s with
lower capacitive loads (shorter cables). Inter-
operability at the higher signalling rates cannot be
assured unless the designer has design control of
the cable and the interface circuits at the both
ends. For inter-operability at signalling rates to
120 k-bits/s, use of EIA/ITA-423-B (ITU v.10) and
EIA/ITA-422-B (ITU v.11) standards are
recommended.
The ST75185C is characterized for operation over
the range of 0°C to 70 °C
.
Table 1.
Device summary
Temperature range
0 to 70 °C
0 to 70 °C
Packages
TSSOP20 (tape and reel)
SO-20 (tape and reel)
Packaging
2500 parts per reel
1000 parts per reel
Order codes
ST75185CTR
ST75185CDR
April 2009
Doc ID 6228 Rev 18
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www.st.com
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Contents
ST75185C
Contents
1
2
3
4
5
6
7
8
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Application information: diodes on power supply . . . . . . . . . . . . . . . . 15
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
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Doc ID 6228 Rev 18
Maximum ratings
ST75185C
2
Table 3.
Symbol
V
DD
V
SS
V
CC
V
I
V
I
V
O
I
O
P
D
T
A
T
STG
T
L
Maximum ratings
Absolute maximum ratings over operating free-air temperature range
Parameter
Supply voltage
(1)
Supply voltage
(1)
Supply voltage
(1)
Input voltage range (Driver)
Input voltage range (Receiver)
Output voltage range (Driver)
Receiver low level output current
Continuous total power dissipation
Operating free-air temperature range
Storage temperature range
Lead temperature 1.6 mm. from case for 10 sec.
Value
15
-15
10
-15 to 7
-30 to 30
-15 to 15
20
See dissipation rating table
0 to 70
-65 to + 150
260
°C
°C
°C
Unit
V
V
V
V
V
V
mA
1. All voltage are with respect to the network ground terminal.
Note:
Absolute maximum ratings are those values beyond which damage to the device may occur.
Functional operation under these condition is not implied.
Dissipation rating table
Package
Power rating
at T
A
≤
25°C
1125 mW
Derating factor
above T
A
=
25°C
9.0 mW/°C
Power rating
at T
A
≤
70°C
720 mW
Table 4.
MICROPACKAGE (D)
Table 5.
Symbol
R
thJC
R
thJA
Thermal data
Parameter
Thermal resistance junction-case
Thermal resistance junction-ambient
TSSOP20
27.22
114.5
(1)
Unit
°C/W
°C/W
1. This value is referred to single-layer PCB, JEDEC standard test board.
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Doc ID 6228 Rev 18
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