MAXIM DS9097U

19-4874; Rev 6/11
DS9097U
Universal 1-Wire COM Port Adapter
FEATURES
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PACKAGE OUTLINE
True-Ground Interface to an RS-232 COM Port
®
for Reading and Writing 1-Wire Devices
Works with Bipolar as well as Unipolar Logic
Signals
Compatible to COM port of (±)5V to (±)12V
(DB9 Version Only) or (±)6V to (±)12V (DB25
Version)
Supports Reading and Writing at Standard and
Overdrive Speeds
Provides Strong Pullup to 5V for Temperature
and EEPROM 1-Wire Devices
Programs 1-Wire EPROM Devices (DB-25
Version with External 12V Power Supply Only)
Communicates at Data Rates of 9.6kbps
(default), 19.2kbps, 57.6kbps, and 115.2kbps
Standard DB9 or DB25 Female Connector and
6-Lead RJ11 Connector for Easy Attachment
of Standard 1-Wire Cables and Probes
Includes DS2502 Identification Chip
(DS9097U-009 Only)
DB9 VERSION
RJ11 PIN 1
SIDE VIEW
DB25 VERSION
RJ11 PIN 1
2.1mm
POWER JACK
- CONTACT
+ CONTACT
SIDE VIEW
PIN ASSIGNMENT
DB9: TXD (3), RXD (2), DTR (4), RTS (7), PC-Ground
(5); all other pins not connected
DB25: TXD (2), RXD (3), DTR (20), RTS (4), PCGround (7); all other pins not connected
REAR VIEW
REAR VIEW
SCHEMATIC (FOR ILLUSTRATION)
DB9 VERSION
RS-232
COM PORT
Note 1: The external supply for the DS9097U-E25
must provide well-regulated 12V at 10mA minimum,
center = GND, outer ring = V+ (Newark Electronics
Stock No. 84F2081, Allied Electronics Stock No. 9289895, Stancor Model STA-300R, or equivalent).
Note 2: The color of the DS9097U plastic case can
vary.
RTS
DTR
RXD
TXD
GND
DS9097U-009
ONLY
5V
REG
4
8
ID
CHIP
DS2480B 5
7
2
ORDERING INFORMATION
PART
DS9097U-009#
DS9097U-S09#
DS9097U-E25#
6
RJ11
6
5
4 1-W
3 GND
2
1
1
TYPE
DB9, with DS2502 ID chip
DB9, no ID chip
DB25, with EPROM write
DB25 VERSION
POWER JACK
RS-232
COM PORT
#Denotes a RoHS-compliant device that may include lead(Pb) that
is exempt under the RoHS requirements.
RTS
DTR
RXD
TXD
GND
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
RJ-11
5V
REG
8
9V
4
6
DS2480B 5
7
2
1
1 of 3
6
5
4 1-W
3 GND
2
1
DS9097U
DESCRIPTION
The DS9097U is a sophisticated RS-232 to 1-Wire adapter, which performs RS-232 level conversion and actively
generates the 1-Wire communication signals. Together with an adequate software driver, it enables a Windows®based PC to directly communicate with any 1-Wire device connected to the adapter’s RJ11 port. The DB9 version
reads and writes any non-EPROM 1-Wire device. To write to EPROM devices, the DB25 version with external
power supply is required. For a list of suitable 1-Wire network cables, refer to the Connectivity Matrix table in the
DS1402x 1-Wire network cables data sheet.
All DS9097U adapters are based on the DS2480B serial 1-Wire line driver chip. The RXD/TXD polarity select input
of the DS2480B is connected to VDD (noninverting).
Free software drivers can be downloaded from www.maxim-ic.com/1-Wiredrivers.
The DS9097U communicates with 1-Wire devices at standard speed as well as overdrive speed. The serial port
must support a data transmission rate of 9600bps. Under software control, the adapter can be set up for RS-232
data rates of 19200bps, 57600bps, and 115200bps. The two higher rates are recommended for communication at
overdrive speed with overdrive-capable devices. Since the DS9097U operates in a byte mode, every data byte
received from the RS-232 port generates eight time slots on the 1-Wire line.
Note that there are some COM ports that use signal levels of less than (±) 5V. The DB9 versions of this adapter do
not work with such ports. The DS9097U-E25 adapter, however, functions in most cases if external power is
supplied. Without EPROM programming, the external power can be anywhere in the range of 6V to 9V. For
EPROM programming the voltage must be at 12V in any case. Before using an externally powered DS9097U-E25
with a COM port of less than (±) 5V, check whether the COM port will not be damaged by 5V on its RXD input.
Windows is a registered trademark of Microsoft Corp.
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DS9097U
REVISION HISTORY
REVISION
DATE
9/00
2/04
8/09
6/11
DESCRIPTION
Initial release
Updated for change in plastic body style; added note that the color of the plastic
body may vary
Added the # sign to all the part numbers in the Ordering Information table;
added the Revision History table
Deleted references to Crypto devices, TMEX, DS9097, and DS9097E; added
reference to the Connectivity Matrix table in the DS1402x 1-Wire network cables
data sheet; updated the URL for software drivers download
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CHANGED
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reserves the right to change the circuitry and specifications without notice at any time.
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© 2011 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.