Thermochron iButton

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3

Note 1:

System requirement.

Note 2:

Maximum allowable pullup resistance is a function of the number of 1-Wire devices in the system and 1-Wire recovery

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

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

Note 3:

Capacitance on IO could be 800pF when power is first applied. If a 2.2k

Ω resistor is used to pull up the data line, 2.5µs

Note 4:

These values are derived from simulation across process, voltage, and temperature and are not production tested.

Note 5:

Input load is to ground.

Note 6:

All voltages are referenced to ground.

Note 7:

Note 8:

Voltage below which, during a falling edge of IO, a logic 0 is detected.

Note 9:

Note 10: Voltage above which, during a rising edge on IO, a logic 1 is detected.

Note 11: The I-V characteristic is linear for voltages less than 1V.

Note 12: Numbers in bold are not in compliance with the published iButton standards. See the

Comparison Table.

Note 13:

Note 14:

Note 15: This number was derived from a test conducted by Cemagref in Antony, France, in July 2000.

http://www.cemagref.fr/English/index.htm Test Report No. E42

Note 16: Total accuracy is

∆ϑ plus 0.25°C quantization due to the 0.5°C digital resolution of the device.

ELECTRICAL CHARACTERISTICS (continued)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

IO PIN: 1-Wire WRITE

Standard speed

60

120

6

15

Write-Zero Low Time

(Notes 1, 12, 13)

Overdrive speed

8.5

15

µs

Standard speed

5

15

Write-One Low Time

(Notes 1, 13)

Overdrive speed

1

2

µs

IO PIN: 1-Wire READ

Standard speed

5

15 -

Read Low Time (Notes 1, 14)

Overdrive speed

1

2 -

µs

Standard speed

15

Read Sample Time

(Notes 1, 14)

Overdrive speed

2

µs

REAL-TIME CLOCK

Frequency Deviation

F

-5°C to +46°C

-48

+46

ppm

TEMPERATURE CONVERTER

Tempcore Operating Range

-40

+85

°C

Conversion Time

19

90

ms

Thermal Response Time

Constant

RESP

(Note 15)

130

s

-40°C to < -30°C

-1.3

+1.3

-30°C to +70°C

-1.0

+1.0

Conversion Error

(Notes 16, 17)

> +70°C to +85°C

-1.3

+1.3

°C

Number of Conversions

(Notes 4, 18)

(See the lifetime graphs.)

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