age range are guaranteed by design and characterization.

Note 2: System requirement.

Note 3: 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.

charged, it does not affect normal communication.

Note 6: Voltage below which, during a falling edge on IO, a logic 0 is detected.

Note 8: Voltage above which, during a rising edge on IO, a logic 1 is detected.

DS1925

iButton High-Capacity Temperature Logger

with 122KB Data-Log Memory

www.maximintegrated.com

Maxim Integrated │ 3

Electrical Characteristics (continued)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

IO PIN: 1-Wire WRITE

Write-Zero Low Time

(Note 2)

Standard speed

60

120

µs

Overdrive speed

6

16

Write-One Low Time (Notes

2, 12)

Standard speed

5

15 - ε

µs

Overdrive speed

0.25

2 - ε

IO PIN: 1-Wire READ

Read Low Time

(Notes 2, 13)

Standard speed

5

15 - δ

µs

Overdrive speed

0.25

2 - δ

Read Sample Time

(Notes 2, 13)

Standard speed

15

µs

Overdrive speed

2

REAL-TIME CLOCK

Accuracy

+25°C

1

Min/Month

Frequency Deviation

-40°C to +85°C

-300

+60

PPM

TEMPERATURE CONVERTER

Conversion Time

10

ms

Thermal Response Time

Constant

iButton package (Note 14)

130

s

Conv. Error

∆J

(Note 15)

-0.5

+0.5

°C

COMMAND DELAYS AND CURRENT

Standard Delay

5

ms

Long Standard Delay

15

ms

XPC Clear Memory (Log)

1500

ms

RTC Start Delay from

Clear Memory State

(Note 16)

2000

ms

XPC Active Current

5

mA