are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure
to absolute maximum rating conditions for extended periods of time may affect reliability.
DC Electrical Characteristics
(V
DD
= 2.7V to 5.5V; T
A
= -55°C to +125°C.)
PARAMETER
Supply Voltage
SYMBOL
V
DD
(Note 1)
0°C to +70°C,
3.0V ≤ V
DD
≤ 5.5V
T
ERR
0°C to +70°C,
2.7V ≤ V
DD
< 3.0V
-55°C to +125°C
-10°C to +85°C,
3.0V ≤ V
DD
≤ 5.5V
T
ERR
-10°C to +85°C,
2.7V ≤ V
DD
< 3.0V
-55°C to +125°C
Low-Level Input Voltage
High-Level Input Voltage
SDA Low-Level Output
Voltage
Input Current Each I/O Pin
V
IL
V
IH
V
OL1
V
OL2
3mA sink current
6mA sink current
0.4 < V
I/O
< 0.9V
DD
Temperature conversion
-55°C to +85°C
Active Supply Current (Note 3)
I
DD
Temperature conversion
+85°C to +125°C
E
2
write
Communication only
Standby Supply Current
T
OUT
Output Logic Voltage
I
STBY
V
OH
V
OL
0°C to +70°C (Note 4)
1mA source current (Note 1)
4mA sink current (Note 1)
2.4
0.4
-0.5
0.7 x V
DD
0
0
-10
CONDITION
MIN
2.7
MAX
5.5
±0.5
±1
±2
±1
±1.5
±2
0.3 x V
DD
V
DD
+ 0.3
0.4
0.6
+10
1
mA
1.25
400
110
800
µA
nA
V
V
V
V
V
µA
°C
°C
UNITS
V
DS1631, DS1631A
Thermometer Error (Note 2)
DS1731 Thermometer Error
(Note 2)
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DS1631/DS1631A/
DS1731
AC Electrical Characteristics
(V
DD
= 2.7V to 5.5V; T
A
= -55°C to +125°C.)
PARAMETER
SYMBOL
9-bit resolution
Temperature Conversion Time
t
TC
10-bit resolution
11-bit resolution
12-bit resolution
SCL Frequency
Bus Free Time Between a STOP
and START Condition
START and Repeated START
Hold Time from Falling SCL
Low Period of SCL
High Period of SCL
Repeated START Condition
Setup Time to Rising SCL
Data-Out Hold Time from
Falling SCL
Data-In Setup Time to
Rising SCL
Rise Time of SDA and SCL
Fall Time of SDA and SCL
STOP Setup Time to Rising
SCL
Capacitive Load for Each
Bus Line
I/O Capacitance
Input Capacitance
Spike Pulse Width that can be
Suppressed by Input Filter
Note
Note
Note
Note
Note
Note
Note
1:
2:
3:
4:
5:
6:
7:
f
SCL
t
BUF
t
HD:STA
t
LOW
t
HIGH
t
SU:STA
t
HD:DAT
t
SU:DAT
t
R
t
F
t
SU:STO
C
B
C
I/O
C
I
t
SP
(Note 5)
(Note 5, 6)
(Note 5)
(Note 5)
(Note 5)
(Note 5)
(Note 5)
(Note 5, 7)
(Note 5, 7)
(Note 5)
CONDITION
High-Precision Digital
Thermometer and Thermostat
MIN
TYP
MAX
93.75
187.5
375
750
UNITS
ms
0
1.3
0.6
1.3
0.6
0.6
0
100
20 + 0.1C
B
20 + 0.1C
B
0.6
400
kHz
µs
µs
µs
µs
µs
0.9
µs
ns
1000
300
ns
ns
µs
400
10
5
0
50
pF
pF
pF
ns
All voltages are referenced to GND.
See
Figure 2
for Typical Operating Curves.
Specified with T
OUT
pin open; A
0
, A
1
, A
2
= 0V or V
DD
; and f
SCL
≥ 2Hz.
Specified with temperature conversions stopped; T
OUT
pin open; SDA = V
DD
; SCL = V
DD
; and A
0
, A
1
, A
2
= 0V or V
DD
.
See Timing Diagram in
Figure 3.
All timing is referenced to 0.9 x V
DD
and 0.1 x V
DD
.
After this period the first clock pulse is generated.
For example, if C
B
= 300pF, then t
R
[min] = t
F
[min] = 50ns.
EEPROM AC Electrical Characteristics
(V
DD
= 2.7V to 5.5V; T
A
= -55°C to +125°C.)
PARAMETER
EEPROM Write Cycle Time
EEPROM Writes
EEPROM Data Retention
SYMBOL
t
wr
N
EEWR
t
EEDR
-55°C to +55°C
-55°C to +55°C
50k
10
CONDITION
MIN
TYP
4
MAX
10
UNITS
ms
Writes
Years
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DS1631/DS1631A/
DS1731
Table 2. Detailed Pin Description
PIN
1
2
3
4
5
6
7
8
SYMBOL
SDA
SCL
T
OUT
GND
A
2
A
1
A
0
V
DD
High-Precision Digital
Thermometer and Thermostat
DESCRIPTION
Data Input/Output Pin for 2-Wire Serial Communication Port. Open-Drain.
Clock Input Pin for 2-Wire Serial Communication Port.
Thermostat Output Pin. Push-Pull.
Ground Pin
Address Input Pin
Address Input Pin
Address Input Pin
Supply Voltage Pin. +2.7V to +5.5V Power-Supply Pin.
V
DD
SCL
SDA
A
0
A
1
A
2
GND
ADDRESS
AND
I/O CONTROL
CONFIGURATION REGISTER
AND CONTROL LOGIC
TEMPERATURE SENSOR
AND ∆Σ ADC
DS1631
TEMPERATURE REGISTER
T
H
REGISTER
T
L
REGISTER
DIGITAL
COMPARATOR/LOGIC
T
OUT
Figure 1. Functional Diagram
0.8
0.6
0.4
DS1631/DS1631A
0.8
0.6
0.4
DS1731
ERROR (°C)
0
-0.2
-0.4
-0.6
-0.8
0
10
-3σ
+3σ
MEAN
ERROR (°C)
0.2
+3σ
0.2
0
-0.2
-0.4
-0.6
-3σ
MEAN
20
30
40
50
60
70
-0.8
-10
0
10
20
30
40
50
60
70
80
REFERENCE TEMPERATURE (°C)
REFERENCE TEMPERATURE (°C)
Figure 2. Typical Operating Curves
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DS1631/DS1631A/
DS1731
High-Precision Digital
Thermometer and Thermostat
ALL TIMING IS REFERENCED TO 0.9 X V
DD
AND 0.1 x V
DD
.
SDA
t
BUF
t
SP
t
R
t
F
t
HD:STA
t
LOW
SCL
t
HD:STA
t
HD:DAT
STOP
START
t
HIGH
t
SU:DAT
t
SU:STO
t
SU:STA
REPEATED
START
Figure 3. Timing Diagram
Table 3. Register Summary
REGISTER NAME
(USER ACCESS)
Temperature (Read Only)
T
H
(Read/Write)
T
L
(Read/Write)
SIZE
(BYTES)
2
2
2
MEMORY
TYPE
SRAM
EEPROM
EEPROM
REGISTER CONTENTS
AND POWER-UP STATE
Measured temperature in two’s complement format.
Power-up state: -60ºC (1100 0100 0000 0000)
Upper alarm trip point in two’s complement format.
Factory state: 15ºC (0000 1111 0000 0000)
Lower alarm trip point in two’s complement format.
Factory state: 10ºC (0000 1010 0000 0000)
Configuration and status information. Unsigned data.