Dallas Semiconductor DS9097U-009 Datasheet
www.dalsemi.com
Universal 1-Wire
DS9097U
®
COM Port Adapter
FEATURES
True-ground interface to an RS232 COM Port
for reading and writing 1-Wire devices
Works with bipolar as well as unipolar logic
signals
Compatible to COM ports of (±)5V to (±)12V
(DB-9 version only) or (±)6V to (±)12V
(DB-25 version)
Supports reading and writing at regular and
Overdrive speeds
Provides strong pull-up to 5V for Tempera-
ture-, Crypto- and EEPROM 1-Wire devices
Programs 1-Wire EPROM devices (DB-25
version with external 12V power supply only)
Communicates at data rates of 9.6 (default),
19.2, 57.6 and 115.2 kbits/s
Standard DB-9 or DB-25 female connector
and 6-lead RJ-11 connector for easy attachment of standard 1-Wire cables and probes
Includes DS2502 identification chip
(DS9097U-009 only)
PIN ASSIGNMENT
DB-25: TXD (2), RXD (3), DTR (20), RTS (4),
PC-Ground (7); all other pins not connected
DB-9: TXD (3), RXD (2), DTR (4), RTS (7),
PC-Ground (5); all other pins not connected
NOTE:
The external supply for the DS9097U-E25 must
provide well regulated 12V @ 10 mA minimum,
center = GND, outer ring = V+ (Newark
Electronics Stock No. 84F2081, Allied
Electronics Stock No. 928-9895, Stancor Model
STA-300R, or equivalent)
ORDERING INFORMATION
DS9097U-009 DB-9, with DS2502 ID chip
DS9097U-S09 DB-9, no ID chip
DS9097U-E25 DB-25, with EPROM write
PACKAGE OUTLINE
DB-09 version
SIDE VIEW
REAR VIEW
DB-25 version
SIDE VIEW
REAR VIEW
SCHEMATIC (for illustration)
DB-9 version
RS232
COM Port
RTS
DTR
RXD
TXD
GND
DB-25 version
RS232
COM Port
RTS
DTR
RXD
TXD
GND
Reg.
Reg.
5V
4
8
7
5V
4
8
7
DS9097U-009
only
6
DS
DS
5
2
1
9V
6
5
2
1
2480B
2480B
RJ-11 pin 1
RJ-11 pin 1
2.1mm
power jack
- contact
+ contact
RJ-11
6
5
4
ID
Chip
Power Jack
3
2
1
6
5
4
3
2
1
1-W
GND
RJ-11
1-W
GND
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DS9097U
DESCRIPTION
The DS9097U is a sophisticated RS232 to 1-Wire Adapter, which performs RS232 level conversion and
actively generates the 1-Wire communication signals. Toget her with an adequate TMEX software driver
it enables an IBM-compatible PC to directly communicate with any 1-Wire device connected to the
adapter's RJ-11 port. The DB-9 version reads and writes any non-EPROM 1-Wire device. To write to
EPROM devices the DB-25 version with external power supply is required.
All DS9097U adapters are based on the DS2480B Serial 1-Wire Line Driver chip and therefore are not a
plug-in replacement for the DS9097 or DS9097E. The RXD/TXD Polarity Select input of the
DS2480B is tied to Vdd (non-inverting). Free software drivers can be downloaded from
http://www.ibutton.com/software/tmex/index.html.
The DS9097U communicates with 1-Wire devices at regular speed as well as Overdrive speed. The serial
port must support a data transmission rate of 9600 bits/s. Under software control, the adapter can be set
up for RS232 data rates of 19200, 57600 and 115200 bits per second. The two higher rates are recommended for communication at Overdrive speed with Overdrive cap able devices. Since the DS9097U
operates in a byte mode, every data byte received from the RS232 port generates ei ght time slots on the
1-Wire line. At 19200 bits/s data rate the DS9097U-E25 is already faster than the DS9097 (E) at 115200
bits/s.
Note that there are some COM ports that use signal levels of less than (±) 5V. The DB-9 versions of this
adapter will not work with such ports. The DS9097U-E25 adapter, however, will function in most cases if
external power is supplied. Without EPROM programming the external power may be an ywhere in the
range of 6 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.
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