DS2422 Maxim, DS2422 Datasheet - Page 4

• Manufacturer Part Number: DS2422
• Description: The DS2422 temperature/data logger combines the core functions of a fully featured data logger in a single chip
• Manufacturer: Maxim

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:
Note 17:
Note 18:
Note 19:
Note 20:
1)
PARAMETER
NAME
t
t
t
t
t
Intentional change, longer recovery time requirement due to modified 1-Wire front end.
W0L
SLOT
RSTL
PDH
PDL
(incl. t
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 the data pin could be 800pF when V
after V
Guaranteed by design, not production tested.
V
V
Voltage below which, during a falling edge on I/O, a logic '0' is detected.
The voltage on I/O needs to be less or equal to V
Voltage above which, during a rising edge on I/O, a logic '1' is detected.
After V
The I-V characteristic is linear for voltages less than 1V.
The earliest recognition of a negative edge is possible at t
Highlighted numbers are NOT in compliance with the published iButton standards. See comparison table below.
Interval during the negative edge on I/O at the beginning of a Presence Detect pulse between the time at which the voltage is
90% of V
 in Figure 16 represents the time required for the pullup circuitry to pull the voltage on I/O up from V
maximum duration for the master to pull the line low is t
 in Figure 16 represents the time required for the pullup circuitry to pull the voltage on I/O up from V
of the bus master. The actual maximum duration for the master to pull the line low is t
This is the expected range when using a crystal equivalent to the Seiko SPT2AF-12.5PF20PPM ..
Time to reach 63% of the temperature change; measured at a temperature transition step from +25°C to +85°C.
A 2-point calibration trim at 3V must be done to achieve the specified accuracy at 3V. See Application Note 2810,
Procedure and Software
The duration is user-programmable from 0ms (code 00h) to 127.5ms (code FFh) with a tolerance of ±0.5ms. See Delay Register,
address 400h, for details.
Guaranteed by design, not production tested to -40°C.
REC
TL
TL
and V
maximum specifications are valid at V
)
PUP
TH
PUP
is crossed during a rising edge on I/O, the voltage on I/O has to drop by V
TH
has been applied the parasite capacitance will not affect normal communications.
are functions of the internal supply voltage, which is a function of V
and the time at which the voltage is 10% of V
61µs
480µs
15µs
60µs
60µs
STANDARD SPEED
MIN
Correction, for details.
(undef.)
(undef.)
60µs
240µs
120µs
STANDARD VALUES
MAX
PUP
7µs
48µs
2µs
8µs
6µs
OVERDRIVE SPEED
= 5.25V. In any case, V
MIN
ILMAX
PUP
whenever the master drives the line low.
4 of 49
W1LMAX
is first applied. If a 2.2k resistor is used to pull up the data line, 2.5µs
REH
PUP
(undef.)
80µs
6µs
24µs
16µs
.
after V
MAX
+ t
F
-  and t
TH
TL
has been previously reached.
< V
65µs
15µs
690µs
60µs
60µs
W0LMAX
TH
STANDARD SPEED
MIN
< V
1)
PUP
PUP
+ t
and the 1-Wire recovery times. The V
HY
.
F
-  respectively.
RLMAX
to be detected as logic '0'.
(undef.)
720µs
63.5µs
287µs
120µs
+ t
DS2422 VALUES
MAX
F
.
IL
IL
to V
to the input high threshold
9.5µs
70µs
2µs
7µs
7.5µs
OVERDRIVE SPEED
MIN
TH
. The actual
DS2422 Trim
(undef.)
80µs
7µs
28µs
12µs
TH
MAX
DS2422
and