Datasheet

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FEATURES
 Provides a simple, low-cost interface to an
RS232C COM Port for reading and writing
iButton
TM
devices (DS9097E required for
programming DS198x Add-Only iButtons)
 Adapter is powered entirely from an RS232
interface (DS9097E may require optional
auxiliary 12V supply)
 Standard DB-9 (DSD9097) or DB-25
(DS9097E) female connector for mating the
adapter to the COM Port of a computer and
RJ-11 connector for easy attachment of a
probe such as the DS9092GT
 DS9097E has an additional 2.1 mm male
power jack to allow for an auxiliary 12V DC
supply for programming Add-Only iButtons
Pin assignment DS9097, DB-9
TXD (3), RXD (2), DTR (4), PC-Ground (5);
all other pins not connected
Pin assignment DS9097E, DB-25
TXD (2), RXD (3), DTR (20), RTS (4), PC-
Ground (7); all other pins not connected
Auxiliary supply should be a 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
DS9097# DB-9 Version
DS9097E# DB-25 Version, EPROM upgraded
# Denotes an RoHS-compliant device that may include
lead(Pb) that is exempt under the RoHS requirements.
DESCRIPTION
The DS9097 COM Port Adapter is a simple, low-cost passive adapter which performs RS232C (±12V)
level conversion, allowing an iButton probe to be connected to the serial port of a computer so that a non-
EPROM iButton can be read and written directly. It can also read all EPROM-based iButtons. The serial
port must support a data transmission rate of 115.2 kbits/s in order to create the 1-Wire
TM
time slots
correctly. Nearly all PCs support the required data rate and are fully compatible with the DS9097. Since
an 8-bit character (6 data bits plus start and stop bit) on the RS232 port operating at 115.2 kbits/s is used
to form a single 1-Wire time slot, the maximum effective 1-Wire transfer rate is 14.4 kbits/s (regular
speed). Details on the operation of the DS9097 are found in Application Note 214, Using a UART to
Implement a 1-Wire Bus Master.
DS9097/DS9097E
COM Port Adapte
r
www.maxim-ic.com
19-4873; 8/09
iButton is a trademark of Maxim Integrated Products, Inc.