The DS75 digital thermometer and thermostat provides 9,
10, 11, or 12-bit digital temperature readings over a -55°C to
+125°C range with ±2°C accuracy over a -25°C to +100°C
range. At power-up, the DS75 defaults to 9-bit resolution
for software compatibility with the LM75. Communication
with the DS75 is achieved via a simple 2–wire serial inter-
face. Three address pins allow up to eight DS75 devices
to operate on the same 2-wire bus, which greatly simplifies
distributed temperature sensing applications.
The DS75 thermostat has a dedicated open–drain output
(O.S.) and programmable fault tolerance, which allows the
user to define the number of consecutive error conditions
that must occur before O.S is activated. There are two
thermostatic operating modes that control thermostat oper-
ation based on userdefined trip-points (T
OS
and T
HYST
).
A block diagram of the DS75 is shown in
Figure 1
and
detailed pin descriptions are given in
Table 2.
Features
●
Temperature Measurements Require No External
Components
●
Measures Temperatures from -55°C to +125°C
(-67°F to +257°F)
●
±2°C Accuracy Over a -25°C to +100°C Range
●
Thermometer Resolution is User-Configurable
from Nine (Default) to 12 Bits (0.5°C to 0.0625°C
Resolution)
●
9-Bit Conversion Time is 150ms (Max)
●
Thermostatic Settings are User-Definable
●
Data is Read/Written Via 2-Wire Serial
(Interface (SDA and SCL Pins)
●
Multidrop Capability Simplifies Distributed
Temperature-Sensing Applications
●
Wide Power-Supply Range (+2.7V to +5.5V).
●
Pin/software Compatible with the LM75
●
Available in 8-Pin µMAX and SO Packages and as a
1.5mm x 1.3mm Flip Chip. See Table 1 for Ordering
Information
Pin Configuration
TOP VIEW
SDA
SCL
O.S.
GND
1
2
3
4
DS75S+ (8-Pin SO — 150mil)
+
+
8
7
6
5
V
DD
A
0
A
1
A
2
DS75
●
Applications Include Personal Computers, Cellular
Base Stations, Office Equipment, or Any Thermally
Sensitive System
Pin Description
SDA
SCL
GND
O.S.
A0
A
1
A
2
V
DD
Open-Drain Data I/O
Clock Input
Ground
Open-Drain Thermostat Output
Address Input
Address Input
Address Input
Power Supply
SDA
SCL
O.S.
GND
1
2
3
4
8
7
6
5
DS75U+ (µMAX)
V
DD
A
0
A
1
A
2
DS75
19-7848; Rev 1; 2/08
DS75
Digital Thermometer and Thermostat
Table 1. Ordering Information
ORDERING
NUMBER
DS75S+
DS75S+T&R
DS75U+
DS75U+T&R
DS75S
DS75S/T&R
DS75U
DS75U/T&R
DS75X/T&R
PACKAGE
MARKING
DS75 (see note)
DS75 (see note)
DS75 (see note)
DS75 (see note)
DS75
DS75
DS75
DS75
DS75
DESCRIPTION
DS75 in Lead-Free 150mil 8-Pin SO
DS75 in Lead-Free 150mil 8-Pin SO, 2500-Piece Tape-and-Reel
DS75 in Lead-Free 8-Pin µMAX
DS75 in Lead-Free 8-Pin µMAX, 3000-Piece Tape-and-Reel
DS75 in 150mil 8-Pin SO
DS75 in 150mil 8-Pin SO, 2500-Piece Tape-and-Reel
DS75 in 8-Pin µMAX
DS75 in 8-Pin µMAX, 3000-Piece Tape-and-Reel
DS75 Flip Chip, 10,000-Piece Tape-and-Reel
Note: A “+” symbol will also be marked on the package near the Pin 1 indicator
Table 2. Detailed Pin Description
PIN
1
2
3
4
5
6
7
8
SYMBOL
SDA
SCL
O.S.
GND
A
2
A
1
V
DD
A
0
DESCRIPTION
Data input/output pin
for 2-wire serial communication port. Open drain.
Clock input pin
for 2-wire serial communication port.
Thermostat output.
Open drain.
Ground pin.
Address input pin.
Address input pin.
Address input pin.
Supply Voltage.
+2.7V to +5.5V supply pin.
www.maximintegrated.com
Maxim Integrated
│
2
DS75
Digital Thermometer and Thermostat
PRECISION
REFERENCE
V
DD
SCL
SDA
A
0
A
1
A
2
ADDRESS
AND
I/O CONTROL
OVERSAMPLING
MODULATOR
DIGITAL
DECIMATOR
CONFIGURATION
REGISTER
TEMPERATURE
REGISTER
O.S.
THERMOSTAT
COMPARATOR
R
P
T
OS
AND T
HYST
REGISTERS
GND
Figure 1. DS75 Functional Block Diagram
www.maximintegrated.com
Maxim Integrated
│
3
DS75
Digital Thermometer and Thermostat
Absolute Maximum Ratings
Voltage on V
DD
, Relative to Ground ....................-0.3V to +7.0V
Voltage on any other pin,
Relative to Ground................................ -0.3V to (V
DD
+ 0.3V)
Operating Temperature .................................... -55°C to +125°C
Storage Temperature ........................................ -55°C to +125°C
Soldering Temperature ........................................+260°C for 10s
*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.
DC Electrical Characteristics
(-55°C to +125°C; 2.7V
≤
V
DD
≤
5.5V)
PARAMETER
Supply Voltage
Thermometer Error
Input Logic High
Input Logic Low
SDA Output Logic Low Voltage
O.S. Saturation Voltage
Input current each I/O pin
I/O Capacitance
Standby Current
Active Current
SYMBOL
V
DD
T
ERR
V
IH
V
OL1
V
OL2
V
OL
V
IL
CONDITION
-25 to +100 (Note 2)
-55 to +125 (Note 2)
(Note 1)
(Note 1)
3mA sink current (Note 1)
6mA sink current (Note 1)
4mA sink current (Notes 1, 2)
0.4 < V
I/O
< 0.9 V
DD
(Notes 3, 4)
Active temp conversions (Notes 3, 4)
Communication only (Notes 3, 4)
-10
0.7 x V
DD
-0.5
0
0
MIN
2.7
MAX
5.5
± 2.0
± 3.0
V
DD
+ 0.5
0.3 x V
DD
0.4
0.6
0.8
+10
10
1
1000
100
UNITS
V
°C
V
V
V
V
µA
pF
µA
µA
I
DD1
I
DD
C
I/O
www.maximintegrated.com
Maxim Integrated
│
4
DS75
Digital Thermometer and Thermostat
AC Electrical Characteristics
(-55°C to +125°C; 2.7V ≤ V
DD
≤ 5.5V)
PARAMETER
Resolution
9-bit conversions
Temperature Conversion Time
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
Input Capacitance
t
CONVT
f
SCL
t
BUF
t
HD:STA
t
HIGH
t
SU:STA
t
HD:DAT
t
SU:DAT
t
R
t
SU:STO
C
B
C
I
5
t
F
t
LOW
(Note 5)
(Notes 5, 6)
(Note 5)
(Note 5)
(Note 5)
(Note 5)
(Note 5)
(Notes 5, 7)
(Notes 5, 7)
(Note 5)
1.3
0.6
1.3
0.6
0.6
0
100
20 + 0.1C
B
20 + 0.1C
B
0.6
1000
300
400
0.9
10-bit conversions
11-bit conversions
12-bit conversions
SYMBOL
CONDITION
MIN
9
TYP
MAX
12
150
300
600
1200
400
kHz
µs
µs
µs
µs
µs
µs
ns
ns
ns
µs
pF
pF
ms
UNITS
bits
Note 1:
All voltages are referenced to ground.
Note 2:
Internal heating caused by O.S. loading will cause the DS75 to read approximately 0.5°C higher if O.S. is sinking the max
rated current.
Note 3:
I
DD
specified with O.S. pin open.
Note 4:
I
DD
specified with V
DD
at 5.0V and SDA, V
SCL
= 5.0V, 0°C to 70°C.
Note 5:
See Timing Diagram in
Figure 2.
All timing is referenced to 0.9 x V
DD
and 0.1 x V
DD
.
Note 6:
After this period, the first clock pulse is generated.
京公网安备 11010802033920号
EEWORLD
