LM95071
SPI/MICROWIRE 13-Bit Plus Sign Temperature Sensor
General Description
The LM95071 is a low-power, high-resolution digital tem-
perature sensor with an SPI and MICROWIRE compatible
interface, available in the 5-pin SOT23. The host can query
the LM95071 at any time to read temperature. Its low oper-
ating current is useful in systems where low power consump-
tion is critical.
The LM95071 has 13-bit plus sign temperature resolution
(0.03125C per LSB) while operating over a temperature
range of -40C to +150C.
The LM95071's 2.4V to 5.5V supply voltage range, fast
conversion rate, low supply current, and simple SPI interface
make it ideal for a wide range of applications.
Applications
n
System Thermal Management
n
Portable Electronic Devices
n
Personal Computers
n
Disk Drives
n
Office Electronics
n
Electronic Test Equipment
Features
n
Small SOT23-5 package saves space
n
Shutdown mode conserves power between temperature
readings
n
Operates over a full -40C to +150C range
n
SPI and MICROWIRE Bus interface
Key Specifications
j
Supply Voltage
2.4V to 5.5V
j
Supply Current
operating
280 A (typ)
shutdown
6 A (typ)
j
Temperature
Accuracy
0C to 70C
1C (max)
-40C to 150C
2C (max)
j
Temperature
Resolution
0.03125 C
Simplified Block Diagram
20106501
TRI-STATE
is a registered trademark of National Semiconductor Corporation.
February 2005
LM95071
13-Bit
Plus
Sign
SPI/MICROWIRE
T
emperature
Sensor
2005 National Semiconductor Corporation
DS201065
www.national.com
Connection Diagram
SOT23-5
20106502
TOP VIEW
NS Package Number MF05A
Ordering Information
Order Number
Top Mark
NS Package
Number
Supply Voltage
Transport Media
LM95071CIMFX
T18C
MF05A
2.4V to 5.5V
3000 Units in Tape and Reel
Pin Descriptions
Pin
Number
Symbol
Name
Description
1
CS
Chip Select input
This pin receives an active-low signal from the controller to select the device.
2
GND
Ground
This is the power and signal ground return.
3
SI/O
Serial Input/Output
This serial, bi-directional, data bus pin transmits and receives signals to and
from the controller. Schmitt trigger input in the input mode.
4
SC
Serial bus clock
This serial clock signal comes from the controller. Schmitt trigger input.
5
V
DD
Positive Supply Voltage
Supply a DC voltage from 2.4V to 5.5V to this pin and bypass with a 0.1 F
ceramic capacitor to ground.
Typical Application
20106503
FIGURE 1. COP Microcontroller Interface
LM95071
www.national.com
2
Absolute Maximum Ratings
(Note 1)
Supply Voltage
-0.3V to 6.0V
Voltage at any Pin
-0.3V to V
DD
+ 0.3V
Input Current at any Pin (Note 2)
5 mA
Storage Temperature
-65C to +150C
ESD Susceptibility (Note 4)
Human Body Model
Machine Model
2000V
200V
Soldering process must comply with National
Semiconductor's Reflow Temperature Profile
specifications. Refer to www.national.com/packaging.
(Note 3)
Operating Ratings
Specified Temperature Range
(Note 5)
T
MIN
to T
MAX
LM95071CIMF
-40C to +150C
Supply Voltage Range (V
DD
)
LM95071CIMF
2.4V to +5.5V
Temperature-to-Digital Converter Characteristics
Unless otherwise noted, these specifica-
tions apply for V
DD
= 3.3V . Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= +25C, unless oth-
erwise noted.
Parameter
Conditions
Typical
(Note 7)
LM95071CIMF
Limits
(Note 8)
Units
(Limit)
Temperature Error
(Note 6)
V
DD
= 3.0V to 3.6V; T
A
= 0C to +70C
1.0
C (max)
V
DD
= 3.0V to 3.6V; T
A
= -40C to +150C
2.0
C (max)
Line Regulation
V
DD
= 3.6V to 5.5V; T
A
= 0C to +70C
+0.3
C/V
(max)
V
DD
= 3.0V to 2.4V; T
A
= 0C to +70C
-0.6
Resolution
14
0.03125
Bits
C
Temperature
Conversion Time
(Note 9)
130
228
ms (max)
Quiescent Current
Operating, Serial Bus Inactive
280
520
A (max)
Shutdown
6
28
A (max)
Logic Electrical Characteristics
DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for V
DD
= 2.4 to 5.5V (Note 6). Bold-
face limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= +25C, unless otherwise noted.
Symbol
Parameter
Conditions
Typical
(Note 7)
Limits
(Note 8)
Units
(Limit)
V
IN(1)
Logical "1" Input Voltage
0.7 x V
DD
V (min)
V
DD
+ 0.3
V (max)
V
IN(0)
Logical "0" Input Voltage
-0.3
V (min)
0.3 x V
DD
V (max)
Input Hysteresis Voltage
V
DD
= 3.0V to 3.6V
0.4
0.33
V (min)
I
IN(1)
Logical "1" Input Current
V
IN
= V
DD
0.005
3.0
A (max)
I
IN(0)
Logical "0" Input Current
V
IN
= 0V
-0.005
-3.0
A (min)
C
IN
All Digital Inputs
20
pF
V
OH
High Level Output Voltage
I
OH
= -400 A
2.25
V (min)
V
OL
Low Level Output Voltage
I
OL
= +1.6 mA
0.4
V (max)
I
O_TRI-STATE
TRI-STATE
Output Leakage
Current
V
O
= GND
V
O
= V
DD
-1
+1
A (min)
A (max)
LM95071
www.national.com
3
Logic Electrical Characteristics
(Continued)
SERIAL BUS DIGITAL SWITCHING CHARACTERISTICS Unless otherwise noted, these specifications apply for V
DD
= 2.4V
to 5.5V (Note 6); C
L
(load capacitance) on output lines = 100 pF unless otherwise specified. Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= +25C, unless otherwise noted.
Symbol
Parameter
Conditions
Typical
(Note 7)
Limits
(Note 8)
Units
(Limit)
t
1
SC (Clock) Period
0.16
DC
s (min)
(max)
t
2
CS Low to SC (Clock) High Set-Up Time
100
ns (min)
t
3
CS Low to Data Out (SO) Delay
70
ns (max)
t
4
SC (Clock) Low to Data Out (SO) Delay
70
ns (max)
t
5
CS High to Data Out (SO) TRI-STATE
200
ns (max)
t
6
SC (Clock) High to Data In (SI) Hold Time
50
ns (min)
t
7
Data In (SI) Set-Up Time to SC (Clock) High
30
ns (min)
t
8
SC (Clock) High to CS High Hold Time
50
ns (min)
20106504
FIGURE 2. Data Output Timing Diagram
20106505
FIGURE 3. TRI-STATE Data Output Timing Diagram
20106506
FIGURE 4. Data Input Timing Diagram
LM95071
www.national.com
4
Logic Electrical Characteristics
(Continued)
Notes
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating
the device beyond its rated operating conditions.
Note 2: When the input voltage (V
I
) at any pin exceeds the power supplies (V
I
<
GND or V
I
>
V
DD
) the current at that pin should be limited to 5 mA.
Note 3: Reflow temperature profiles are different for lead-free and non-lead-free packages.
Note 4: Human body model, 100 pF discharged through a 1.5 k
resistor. Machine model, 200 pF discharged directly into each pin.
Note 5: The life expectancy of the LM95071 will be reduced when operating at elevated temperatures. LM95071
JA
(thermal resistance, junction-to-ambient) when
attached to a printed circuit board with 2 oz. foil is summarized in the table below:
Device Number
NS Package
Number
Thermal
Resistance (
JA
)
LM95071CIMF
MF05A
250C/W
Note 6: The LM95071 will operate properly over the V
DD
supply voltage range of 2.4V to 5.5V.
Note 7: Typicals are at T
A
= 25C and represent most likely parametric norm.
Note 8: Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 9: This specification is provided only to indicate how often temperature data is updated. The LM95071 can be read at any time without regard to conversion
state (and will yield last conversion result). A conversion in progress will not be interrupted. The output shift register will be updated at the completion of the read
and a new conversion restarted.
Note 10: For best accuracy, minimize output loading. Higher sink currents can affect sensor accuracy with internal heating.
LM95071
www.national.com
5
PDF 
ZIP