Datasheet

DS1921G
Thermochron iButton
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
PUP
= +2.8V to +5.25V, T
A
= -40°C to +85°C.)
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.
IO Voltage Range Relative to GND ..........................-0.5V to +6V
IO Sink Current....................................................................20mA
Operating Temperature Range ..........................-40°C to +85°C*
Storage Temperature Range..............................-40°C to +50°C*
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
IO PIN: GENERAL DATA
1-Wire Pullup Resistance R
PUP
(Notes 1, 2) 2.2 k
Input Capacitance C
IO
(Notes 3, 4) 100 800 pF
Input Load Current I
L
IO pin at V
PUP
(Note 5) 10 µA
V
PUP
> 4.5V 1.14 2.70
High-to-Low Switching Threshold
(Notes 4, 6, 7, 8)
V
TL
0.71 2.70
V
Input Low Voltage V
IL
(Notes 1, 6, 9) 0.30 V
V
PUP
> 4.5V 1.00 2.70
Low-to-High Switching Threshold
(Notes 4, 6, 7, 10)
V
TH
0.66 2.70
V
Output Low Voltage at 4mA V
OL
(Notes 6, 11) 0.4 V
Standard speed, R
PUP
= 2.2k 5
Overdrive speed, R
PUP
= 2.2k 2
Recovery Time (Notes 1, 4) t
REC
Overdrive speed, directly prior to reset
pulse; R
PUP
= 2.2k
5
µs
Standard speed 65
Time-Slot Duration (Notes 1, 12) t
SLOT
Overdrive speed 8
µs
IO PIN: 1-Wire RESET, PRESENCE-DETECT CYCLE
Standard speed, V
PUP
> 4.5V 480 640
Standard speed 540 640
Overdrive speed, V
PUP
> 4.5V 48 80
Reset Low Time (Notes 1,12) t
RSTL
Overdrive speed 58 80
µs
Standard speed 15 60
Presence-Detect High
Time (Note 12)
t
PDH
Overdrive speed 1.1 6
µs
Standard speed 60 270
Overdrive speed, V
PUP
> 4.5V 7.5 24
Presence-Detect Low
Time (Note 12)
t
PDL
Overdrive speed 7.5 32
µs
Standard speed 60 75
Presence-Detect
Sample Time (Notes 1, 4)
t
MSP
Overdrive speed 6 8.6
µs
* Storage or operation above +50°C significantly reduces battery life.