AVAILABLE
Functional Diagrams
Pin Configurations appear at end of data sheet.
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
FEATURES
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)
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), PC-
Ground (7); all other pins not connected
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. 928-
9895, Stancor Model STA-300R, or equivalent).
Note 2: The color of the DS9097U plastic case can
vary.
ORDERING INFORMATION
PART
TYPE
DS9097U-009#
DB9, with DS2502 ID chip
DS9097U-S09#
DB9, no ID chip
DS9097U-E25#
DB25, with EPROM write
#Denotes a RoHS-compliant device that may include lead(Pb) that
is exempt under the RoHS requirements.
PACKAGE OUTLINE
DB9 VERSION
SIDE VIEW
REAR VIEW
RJ11 PIN 1
DB25 VERSION
RJ11 PIN 1
SIDE VIEW
REAR VIEW
+ CONTACT
- CONTACT
2.1mm
POWER JACK
SCHEMATIC (FOR ILLUSTRATION)
DB9 VERSION
6
4
RTS
DTR
RXD
TXD
GND
RS-232
COM PORT
5V
REG
DS2480B
1
7
8
5
2
RJ11
1-W
GND
6
5
4
3
2
1
ID
CHIP
DS9097U-009
ONLY
DB25 VERSION
6
4
RTS
DTR
RXD
TXD
GND
RS-232
COM PORT
5V
REG
DS2480B
1
7
8
5
2
RJ-11
1-W
GND
6
5
4
3
2
1
POWER JACK
9V
DS9097U
Universal 1-
Wire COM Port Adapter
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
19-4874; Rev 6/11
DS9097U
2 of 3
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.
DS9097U
REVISION HISTORY
REVISION
DATE
DESCRIPTION
PAGES
CHANGED
9/00 Initial release —
2/04
Updated for change in plastic body style; added note that the color of the plastic
body may vary
1
8/09
Added the # sign to all the part numbers in the Ordering Information table;
added the Revision History table 1, 3
6/11
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
1, 2
3
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
© 2011 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.
