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FEATURES
§ High-Speed 12Mbps Universal Serial Bus
(USB) Interface
§ Supports Standard and Overdrive 1-Wire®
Communication
§ Slew-Rate-Controlled 1-Wire Timing and
Active Pullup for Improved 1-Wire Network
Performance
§ DS9490R has an RJ11 Interface for Standard
Connectivity Accessories such as the
DS1402D-DR8
§ DS9490B has an iButton® Interface and
Retains a Fixed iButton
§ Built-In Custom DS2401 Identification Chip
§ Reads all 1-Wire and iButton Devices. Writes
All Except EPROM 1-Wire/iButton Devices
APPLICATIONS
§ Software Authorization—Protection against
software piracy by tying software operation to
the presence of iButton hardware.
§ iButton Initialization and Download—
Loggers like the Thermochron® can be
missioned and downloaded. Monetary
iButtons can be refilled with money.
§ Demonstration—Demonstrate the features of
iButtons or 1-Wire chips on personal
computers.
§ Development—Aid development of 1-Wire
applications by providing a PC interface to
verify device contents and state.
TYPICAL OPERATING CIRCUIT
PC USB
DS9490B iButton
PC USB DS9490R
DS1402D-DR8
ORDERING INFORMATION
PART DESCRIPTION
DS9490B USB Single F5 iButton Holder
with Protective Cap
DS9490R USB to 1-Wire RJ11
PACKAGING/SHIPPING
INFORMATION
The part is shipped individually in an anti-static
bag.
DESCRIPTION
The DS9490B is a USB bridge and holder for a single F5-size iButton. The iButton is securely held
behind a latched door. The DS9490R is a USB bridge with 1-Wire RJ11 interface to accommodate 1-
Wire receptacles and networks. The DS1402D-DR8 (Blue Dot™) can readily be used in conjunction with
the DS9490R to create an iButton PC reader. Both adapters are based on the DS2490 USB to 1-Wire
bridge chip.
PC software drivers for Windows® 98, Windows 2000, Windows ME, and Windows XP can be found on
the iButton website under software support at: http://www.ibutton.com/software/tmex/index.html
DS9490R/DS9490B
USB to 1-Wire/iButton Adapter
www.maxim-ic.com
1-Wire, iButton, and Thermochron are registered trademarks of
Dallas Semiconductor.
Blue Dot is a trademark of Dallas Semiconductor.
Windows is a re
g
istered trademark of Micosoft Cor
p
.
DS9490
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Figure 1. DS9490R
* Color subject to change
Figure 2. DS9490B
*
* Color subject to change
*Note: To eject an iButton, insert a straightened paper clip into the side access hole of the DS9490B.
Push the paper clip in the direction of the iButton. A different iButton can then be inserted. The
data contact faces down and away from the embossed ‘i’. Before inserting the paper clip
disconnect the DS9490B from the USB bus.
Each USB bridge contains a unique built-in identification chip. The identification chip is a custom
DS2401 that is a 64-bit ID number (see Figure 3).
Figure 3. DS2401 ID CHIP 64-BIT LASERED ROM
MSB LSB
8-BIT
CRC CODE
12-BIT
FIXED
(000H)
36-BIT SERIAL
NUMBER
8-BIT FAMILY
CODE (81H)
MSB LSB MSB LSB MSB LSB MSB LSB
DS9490
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PIN CONFIGURATION
Figure 4. 1-WIRE RJ11 SOCKET FOR DS9490R
PIN SIGNAL
NAME DESCRIPTION
1VDD 5VDC Output
2GND Power Ground
3OW 1-Wire Data
4GND_OW 1-Wire Return
5, 6 N.C. No Connection
6N.C. No Connection
Figure 5. iBUTTON SOCKET FOR DS9490B
PIN SIGNAL
NAME DESCRIPTION
1OW 1-Wire Data
2GND_OW 1-Wire Return
1
2
*
*Note: The data contact faces down and away from the embossed ‘i’. Once the iButton is inserted in the
enclosure, snap the end cap over it. The end cap is removed by depressing the release tab,
swinging it fully open, and sliding out the hinge.
Looking into Female RJ11
654321
DS9490
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MECHANICAL DIMENSIONS
All dimensions are in millimeters.
Figure 6. DS9490R
11.66
3.12
20.42
42.65
13.89
21.54
Figure 7. DS9490B
3.28
11.66
56.82
24.94
16.54
8.74
ENVIRONMENTAL REQUIREMENTS
CONDITION PARAMETER VALUE
Storage Temperature -10°C to +85°C
Storage Relative humidity, noncondensing 95%
Storage Duration 1yr (max) at 95%RH and +85°C
Operating Temperature 0°C to +70°C
Operating Relative humidity, noncondensing 80%
DS9490
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ELECTRICAL CHARACTERISTICS
PARAMETER SPECIFICATION
USB I/F As defined in Chapter 7 of the USB Specification*
1-Wire I/F See the DS2490 data sheet**
The DS9490R and DS9490B consume 58mA in USB active mode and 0.5mA in suspend mode*. The
DS9490R has the VBUS power and ground available on the RJ11 connector. In active mode the current
available to an externally powered fixture is 42mA* (100mA to 58mA); however it is recommended that
no more than 25mA be used. Note that in suspend mode there is zero current available to an external
circuit. An external circuit cannot detect when the module is in suspend or active mode. Consequently,
when in suspend mode, the DS9490R module with external circuit combination is in violation of the USB
power specification. Application developers should be aware of this when using this module in
conjunction with an externally powered circuit on power restricted platforms such as laptops.
*Guaranteed by design, not production tested.
**Tested at DS2490 component level.
Figure 8. FUNCTIONAL DIAGRAM
EMI Filter
VBUS
D-
D+
GND VIN VOUT
EN
N/C GND
LP2980IM5-3.3
PMOD VD
NC NC
NC NC
NC NC
VB X1
SUSO X0
D- NC
D+ VPP
NC NC
OW NC
NC NC
GND NC
DS2490
C2
1.0uF
EMI Filter
C3
4.7
R2 24
R3 24
R1
1.5K
C1
0.1uF
OW
GND
DS2401
OW
GND
D
S9503
USB
Connector
C6
33pF
C5
33pF
X1
12Mhz
L1
L2
C7
33pF
C8
33pF
U1
U2
U3
U4
J2
1
2
1
2
J1
1
2
3
41
3
4
5
2
1
5
7
8
12
24
19
20
17
10
1
2
3
4
5
6
Female RJ11
DS9490R
DS9490B
1
2
iButton Socket
J3
6
5
3
1
