DS9490B Datasheet, PDF (5/5 Pages) Dallas Semiconductor – USB to 1-Wire/iButton Adapter

ELECTRICAL CHARACTERISTICS
DS9490
PARAMETER
USB I/F
1-Wire I/F
SPECIFICATION
As defined in Chapter 7 of the USB Specification*
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 V_BUS 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
USB
Connector
1
VBUS
D-
2
3
D+
GND ⁴
EMI Filter _L1
EMI Filter _L2
J1
C2
1.0uF
LP2980IM5-3.3
1
VIN
3 _EN
5
VOUT
C3
4 N/C
GND
4.7
2
R1
U1
1.5K
R2 24
R3 24
C7
33pF
C8
33pF
C1
0.1uF
DS2490
1
PMOD
NC
NC
5 ^NC
VB
7 ^SUSO
D-
8 ^D+
NC
10 _OW
NC
12 _GND
U2
24
VD
NC
NC
NC
X1 ¹⁹
X0 ²⁰
NC ₁₇
VPP
NC
NC
NC
NC
1
X1
12Mhz
3
C6
33pF
C5
33pF
DS2401 ^U3
2
OW
1
GND
DS9503
1
6
OW
5
GND ₂
U4
Female RJ11
1
2
3
4
5
6
J2
DS9490R
iButton Socket
1
2
J3
DS9490B
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