Datasheet

DS1721
15 of 17
DC ELECTRICAL CHARACTERISTICS:
DIGITAL THERMOMETER (-55°C to +125°C; 2.7V £ V
DD
£ 5.5V)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES
-10°C to +85°C,
3.0V≤V
DD
≤5.5V
±1.0 °C
-10°C to +85°C,
2.7V≤V
DD
<3.0V
±1.5 °C
DS1721
Thermometer Error
T
ERR
-55°C to +125°C ±2.0 °C
Resolution 9 12 bits
9-bit
Conversions
93.75
10-bit
Conversions
187.5
11-bit
Conversions
375
Conversion Time t
CONVT
12-bit
Conversions
750
ms
AC ELECTRICAL CHARACTERISTICS:
2-WIRE INTERFACE (-55°C to +125°C; V
DD
=2.7V to 5.5V)
PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES
SCL Clock
Frequency
f
SCL
Fast Mode
Standard Mode
0
0
400
100
KHz
Bus Free Time
Between a STOP
and START
Condition
t
BUF
Fast Mode
Standard Mode
1.3
4.7
µs
Hold Time
(Repeated) START
Condition
t
HD:STA
Fast Mode
Standard Mode
0.6
4.0
µs 5
Low Period of
SCL Clock
t
LOW
Fast Mode
Standard Mode
1.3
4.7
µs
High Period of
SCL Clock
t
HIGH
Fast Mode
Standard Mode
0.6
4.0
µs
Setup Time for a
Repeated START
Condition
t
SU:STA
Fast Mode
Standard Mode
0.6
4.7
µs
Data Hold Time t
HD:DAT
Fast Mode
Standard Mode
0
0
0.9 µs 6
Data Set-up Time t
SU:DAT
Fast Mode
Standard Mode
100
250
ns 7
Rise Time of both
SDA and SCL
Signals
t
R
Fast Mode
Standard Mode
20+0.1
C
B
300
1000
ns 7
Fall Time of both
SDA and SCL
Signals
t
F
Fast Mode
Standard Mode
20+0.1
C
B
300
1000
ns 8
Set-up time for
STOP Condition
t
SU:STO
Fast Mode
Standard Mode
0.6
4.0
µs