or operation above +50°C significantly reduces battery life.
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.
Operating Temperature Range ..........................-40°C to +85°C*
Storage Temperature Range..............................-40°C to +50°C*
ELECTRICAL CHARACTERISTICS
(V
PUP
= +2.8V to +5.25V, T
A
= -40°C to +85°C.)
PARAMETER
IO PIN: GENERAL DATA
1-Wire Pullup Resistance
Input Capacitance
Input Load Current
High-to-Low Switching Threshold
(Notes 4, 6, 7, 8)
Input Low Voltage
Low-to-High Switching Threshold
(Notes 4, 6, 7, 10)
Output Low Voltage at 4mA
R
PUP
C
IO
I
L
V
TL
V
IL
V
TH
V
OL
(Notes 1, 2)
(Notes 3, 4)
IO pin at V
PUP
(Note 5)
V
PUP
> 4.5V
(Notes 1, 6, 9)
V
PUP
> 4.5V
(Notes 6, 11)
Standard speed, R
PUP
= 2.2k
Recovery Time (Notes 1, 4)
t
REC
Overdrive speed, R
PUP
= 2.2k
Overdrive speed, directly prior to reset
pulse; R
PUP
= 2.2k
Standard speed
Overdrive speed
Standard speed, V
PUP
> 4.5V
Standard speed
Overdrive speed, V
PUP
> 4.5V
Overdrive speed
Presence-Detect High
Time (Note 12)
Presence-Detect Low
Time (Note 12)
Presence-Detect
Sample Time (Notes 1, 4)
t
PDH
Standard speed
Overdrive speed
Standard speed
t
PDL
Overdrive speed, V
PUP
> 4.5V
Overdrive speed
t
MSP
Standard speed
Overdrive speed
5
2
5
65
8
480
540
48
58
15
1.1
60
7.5
7.5
60
6
640
640
80
80
60
6
270
24
32
75
8.6
μs
μs
μs
μs
μs
μs
1.00
0.66
1.14
0.71
100
2.2
800
10
2.70
2.70
0.30
2.70
2.70
0.4
k
pF
μA
V
V
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Time-Slot Duration (Notes 1, 12)
t
SLOT
IO PIN: 1-Wire RESET, PRESENCE-DETECT CYCLE
Reset Low Time (Notes 1,12)
t
RSTL
2
Maxim Integrated
DS1921G
Thermochron iButton Device
ELECTRICAL CHARACTERISTICS (continued)
(V
PUP
= +2.8V to +5.25V, T
A
= -40°C to +85°C.)
PARAMETER
IO PIN: 1-Wire WRITE
Standard speed
Write-Zero Low Time
(Notes 1, 12, 13)
Write-One Low Time
(Notes 1, 13)
IO PIN: 1-Wire READ
Read Low Time (Notes 1, 14)
Read Sample Time
(Notes 1, 14)
REAL-TIME CLOCK
Frequency Deviation
TEMPERATURE CONVERTER
Tempcore Operating Range
Conversion Time
Thermal Response Time
Constant
Conversion Error
(Notes 16, 17)
Number of Conversions
N
CONV
T
TC
t
CONV
RESP
F
SYMBOL
CONDITIONS
MIN
60
6
8.5
5
1
5
1
t
RL
+
t
RL
+
-48
-40
19
TYP
MAX
120
15
15
15
2
15 -
2-
15
2
+46
+85
90
UNITS
t
W0L
Overdrive speed, V
PUP
> 4.5V
Overdrive speed
Standard speed
Overdrive speed
Standard speed
Overdrive speed
Standard speed
Overdrive speed
-5°C to +46°C
μs
t
W1L
μs
t
RL
t
MSR
μs
μs
ppm
°C
ms
s
(Note 15)
-40°C to < -30°C
-30°C to +70°C
> +70°C to +85°C
(Notes 4, 18)
-1.3
-1.0
-1.3
130
+1.3
+1.0
+1.3
°C
—
(See the lifetime graphs.)
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Note 10:
Note 11:
Note 12:
Note 13:
Note 14:
Note 15:
Note 16:
System requirement.
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.
Capacitance on IO could be 800pF when power is first applied. If a 2.2kΩ resistor is used to pull up the data line, 2.5µs
after V
PUP
has been applied, the parasite capacitor does not affect normal communication.
These values are derived from simulation across process, voltage, and temperature and are not production tested.
Input load is to ground.
All voltages are referenced to ground.
V
TL
and V
TH
are functions of the internal supply voltage, which is a function of V
PUP
and the 1-Wire recovery times. The
V
TH
and V
TL
maximum specifications are valid at V
PUP
= 5.25V. In any case, V
TL
< V
TH
< V
PUP
.
Voltage below which, during a falling edge of IO, a logic 0 is detected.
The voltage on IO must be less than or equal to V
ILMAX
whenever the master drives the line low.
Voltage above which, during a rising edge on IO, a logic 1 is detected.
The I-V characteristic is linear for voltages less than 1V.
Numbers in
bold
are
not
in compliance with the published iButton device standards. See the
Comparison Table.
ε
in Figure 15 represents the time required for the pullup circuitry to pull the voltage on the IO pin up from V
IL
to V
TH
. The
actual maximum duration for the master to pull the line low is t
W1LMAX
+ t
F
-
ε
and t
W0LMAX
+ t
F
-
ε,
respectively.
δ
in Figure 15 represents the time required for the pullup circuitry to pull the voltage on the IO pin up from V
IL
to the input
high threshold of the bus master. The actual maximum duration for the master to pull the line low is t
RLMAX
+ t
F
.
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
Total accuracy is
Δϑ
plus 0.25°C quantization due to the 0.5°C digital resolution of the device.
Maxim Integrated
3
DS1921G
Thermochron iButton Device
ELECTRICAL CHARACTERISTICS (continued)
(V
PUP
= +2.8V to +5.25V, T
A
= -40°C to +85°C.)
Note 17: WARNING:
Maxim data-logger products are 100% tested and calibrated at time of manufacture to ensure that they meet
all data sheet parameters, including temperature accuracy. As with any sensor-based product, user shall be responsible
for occasionally rechecking the temperature accuracy of the product to ensure it is still operating properly. Furthermore, as
with all products of this type, when deployed in the field and subjected to handling, harsh environments, or other
hazards/use conditions, there may be some extremely small but nonzero logger failure rate. In applications where the fail-
ure of any logger is a concern, user shall assure that redundant (or other primary) methods of testing and determining the
handling methods, quality, and fitness of the articles and products are implemented to further mitigate any risk.
Note 18:
The number of temperature conversions (= samples) possible with the built-in energy source depends on the operating and
storage temperature of the device. When not in use for a mission, the RTC oscillator should be turned off and the device
should be stored at a temperature not exceeding +25°C. Under this condition the shelf life time is 10 years minimum.
COMPARISON TABLE
LEGACY VALUES
PARAMETER
STANDARD SPEED (μs)
MIN
t
SLOT
(including
t
REC
)
t
RSTL
t
PDH
t
PDL
t
W0L
61
480
15
60
60
MAX
(undefined)
(undefined)
60
240
120
OVERDRIVE SPEED (μs)
MIN
7
48
2
8
6
MAX
(undefined)
80
6
24
16
MIN
65*
540
15
60
60
DS1921G VALUES
STANDARD SPEED (μs)
MAX
(undefined)
640
60
270
120
OVERDRIVE SPEED (μs)
MIN
8*
58
1.1
7.5
8.5
MAX
(undefined)
80
6
32
15
*Intentional
change; longer recovery time between time slots.
Note:
Numbers in
bold
are
not
in compliance with the published iButton device standards.
iButton CAN PHYSICAL SPECIFICATION
SIZE
WEIGHT
See the
Package Information
section.
Ca. 3.3g
4
Maxim Integrated
DS1921G
Thermochron iButton Device
RTC Deviation vs. Temperature
4
UPPER LIMIT
2
RTC DEVIATION (MINUTES/MONTH)
0
LOWER LIMIT
-2
-4
-6
-8
-10
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
TEMPERATURE (°C)
Minimum Product Lifetime vs. Temperature at Different Sample Rates
1. Brief descriptionThis article introduces a concise method for setting interrupts in the TMS320C6000 series. Through the example of timer interrupt, MCBSP serial port receiving interrupt and externa...
I have a machine like this, with a motherboard and a panel. There is a screen and a keyboard on the panel, which is where the operator controls and sets various parameters. There are two serial ports ...
Today, I encountered a problem with the callback function-based lwip without an operating system. The constant string tcp_write+tcp_output can be sent out, but the variable character array or pointer ...
Many peripheral chips are connected to the main chip through the i2c bus, and the main chip sends commands through i2c to initialize the peripheral chips.I.MX5x has at least 3 peripheral chips that ne...
Questions: Hardware and software access USB RAM buffer at the same time, causing data to be messed up or lost.The process of causing garbled code:1. Software sets USB Valid2. Turn off the general inte...
How to design an SD card based on NIOS Ⅱ? Designing with SOPC bulider and NIOS II is a combination of hardware and software. SOPC builds the SD card controller (hardware), and NIOSS II writes the corr...
1. Several nouns
ABI:
The specifications that an executable file must follow in order to run in a specific execution environment;
Separately generated relocatabl...[Details]
Whether it is an electric car or an ordinary fuel car, for the vast majority of car buyers, the final cost of use is what they care about most. For fuel cars, how to save fuel is what drivers care ...[Details]
As the main model among new energy vehicles, pure electric vehicles have received strong support and encouragement from the country in recent years, and their development is changing with each pass...[Details]
Multi-touch mobile phone
Multi-touch is a system that can respond to multiple touches on the screen at the same time. Multi-touch phones are divided into capacitive and resistive types. Capaci...[Details]
On August 22, Lantu Motors officially launched its Lanhai Intelligent Hybrid technology via an online livestream. This intelligent hybrid technology, which integrates a full-range 800V high-voltage...[Details]
Based on the commutation technology, thyristor rectifiers are classified into two main types. Line-commutated and force-commutated inverters are commonly used, while other commutated inverters, nam...[Details]
The MCX E series is the most reliability- and safety-focused series in NXP's extensive MCX product portfolio.
With the launch of this series, NXP has further enriched its 5V-compatible MCU pr...[Details]
To improve the lateral active safety of intelligent connected vehicles, the identification and definition of unexpected functional safety scenarios for the EPS (Electronic Steering System) ...[Details]
In the period after the switching power supply achieved the "20 kHz" revolution in the 1970s, although improvements and enhancements were made in circuit technology, the development level of the se...[Details]
Inverter power supplies on the market can generally be divided into two categories: sine wave inverters and square wave inverters. Some engineers also like to categorize pure sine wave inverters as...[Details]
A pure sine wave inverter has a good output waveform with very low distortion, and its output waveform is essentially the same as the AC waveform of the mains power grid. In fact, the AC power prov...[Details]
Tires are a very important component for cars. They are related to the driving experience of the vehicle. We are almost inseparable from cars in our daily lives. For tires, according to the role of...[Details]
As a pioneer in the new smart home concept, robot vacuums have captured a significant market share. Robot vacuums, also known as automatic sweepers, smart vacuums, or robot vacuums, are smart home ...[Details]
Nascent Micro is launching devices covering a wide range of power applications, including gallium nitride (GaN) drivers, dual-channel automotive drivers, and battery protection MOSFETs.
...[Details]
introduction
With the development of the information superhighway and the internet, broadcast television has become increasingly widespread worldwide. Television information has emerged in var...[Details]
Microcontroller MCU
京公网安备 11010802033920号
EEWORLD
