Serial Number iButton

2

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ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

Note 1:

All voltages are referenced to ground.

Note 2:

External pullup voltage. See Figure 4.

Note 3:

System requirement.

Note 4:

Wire recovery times. The specified value here applies to systems with only one device and with the minimum 1-Wire recov-

ery times. For more heavily loaded systems, an active pullup such as that found in the DS2480B may be required.

Note 5:

Capacitance on the IO pin could be 800pF when power is first applied. If a 5k

Ω resistor is used to pull up the IO line to

Note 6:

Guaranteed by design, simulation only. Not production tested.

Note 7:

Input load is to ground.

IO Voltage Range to GND .....................................-0.5V to +6.0V

IO Sink Current....................................................................20mA

Junction Temperature ......................................................+125°C

Storage Temperature Range .............................-55°C to +125°C

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

IO PIN: GENERAL DATA

1-Wire Pullup Voltage

(Notes 1, 2)

2.8

6.0

V

1-Wire Pullup Resistance

(Notes 3, 4)

0.6

5

k

Input Capacitance

(Notes 5, 6)

100

800

pF

Input Load Current

(Note 7)

0.25

μA

Input Low Voltage

(Notes 1, 3, 8)

0.3

V

Input High Voltage

(Notes 1, 9)

2.2

V

Output Low Voltage at 4mA

(Note 1)

0.4

V

Operating Charge

(Notes 6, 10)

30

nC

Recovery Time

(Note 3)

1

μs

Time Slot Duration

(Note 3)

61

μs

IO PIN: 1-Wire RESET, PRESENCE-DETECT CYCLE

Reset Low Time

(Notes 3, 11)

480

μs

Reset High Time

(Notes 3, 12)

480

μs

Presence-Detect High Time

15

60

μs

Presence-Detect Low Time

(Note 13)

60

240

μs

Presence-Detect Sample Time

(Note 3)

60

75

μs

IO PIN: 1-Wire WRITE

Write-Zero Low Time

(Notes 3, 14)

60

120

μs

Write-One Low Time

(Notes 3, 14)

1

15

μs

IO PIN: 1-Wire READ

Read Low Time

(Notes 3, 15)

1

15 -

μs

Read Sample Time

(Notes 3, 15)

15

μs