LM70
SPI/MICROWIRE
TM
10-Bit plus Sign Digital Temperature
Sensor
General Description
The
LM70
is
a
temperature
sensor,
Delta-Sigma
analog-to-digital converter with an SPI and MICROWIRE
compatible interface available in LLP and MSOP 8-pin pack-
ages. The host can query the LM70 at any time to read tem-
perature. A shutdown mode decreases power consumption
to less than 10 A. This mode is useful in systems where low
average power consumption is critical.
The LM70 has 10-bit plus sign temperature resolution
(0.25C per LSB) while operating over a temperature range
of -55C to +150C.
The LM70's 2.65V to 5.5V supply voltage range, low supply
current and simple SPI interface make it ideal for a wide
range of applications. These include thermal management
and protection applications in hard disk drives, printers, elec-
tronic test equipment, and office electronics.
Applications
n
System Thermal Management
n
Personal Computers
n
Disk Drives
n
Office Electronics
n
Electronic Test Equipment
Features
n
0.25C temperature resolution.
n
Shutdown mode conserves power between temperature
reading
n
SPI and MICROWIRE Bus interface
n
MSOP-8 and LLP-8 packages save space
Key Specifications
j
Supply Voltage
2.65V to 5.5V
j
Supply Current
operating
260A (typ)
490A (max)
shutdown
12A (typ)
j
Temperature
Accuracy
-40C to 85C
2C(max)
-10C to 65C
+1.5/-2C(max)
-55C to 125C
+3/-2C(max)
-55C to 150C
+3.5/-2C(max)
Simplified Block Diagram
MICROWIRE
is a registered trademark of National Semiconductor Corporation.
DS101223-1
July 2000
LM70
SPI/MICROWIRE10-Bit
plus
Sign
Digital
T
emperature
Sensor
2000 National Semiconductor Corporation
DS101223
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Connection Diagrams
Ordering Information
Order Number
Package
Marking
NS Package
Number
Supply Voltage
Transport Media
LM70CILD-3
T33
LLP-8, LDA08A
2.65V to 3.6V
_ Units in Rail
LM70CILDX-3
T33
LLP-8, LDA08A
2.65V to 3.6V
_ Units in Rail
LM70CILD-5
T35
LLP-8, LDA08A
4.5V to 5.5V
_ Units in Tape and Reel
LM70CILDX-5
T35
LLP-8, LDA08A
4.5V to 5.5V
_ Units in Tape and Reel
LM70CIMM-3
T04C
MSOP-8, MUA08A
2.65V to 3.6V
250 Units in Rail
LM70CIMMX-3
T04C
MSOP-8, MUA08A
2.65V to 3.6V
3500 Units in Tape and Reel
LM70CIMM-5
T03C
MSOP-8, MUA08A
4.5V to 5.5V
250 Units in Rail
LM70CIMMX-5
T03C
MSOP-8, MUA08A
4.5V to 5.5V
3500 Units in Tape and Reel
Pin Descriptions
Label
SOP-8
Pin #
LLP-8
Pin #
Function
Typical Connection
SI/O
1
1
Input/Output - Serial bus bi-directional data
line. Schmitt trigger input.
From and to Controller
SC
2
3
Clock - Serial bus clock Schmitt trigger input
line.
From Controller
GND
4
7
Power Supply Ground
Ground
V
+
5
5
Positive Supply Voltage Input
DC Voltage from 2.65V to 5.5V. Bypass
with a 0.1 F ceramic capacitor.
CS
7
8
Chip Select input.
From Controller
NC
3, 6, 8
2, 4, 6
No Connect
These pins are not connected to the
LM70 die in any way.
MSOP-8
DS101223-2
TOP VIEW
NS Package Number MUA08A
LLP-8
DS101223-25
TOP VIEW
NS Package Number LDA08A
LM70
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2
Typical Application
DS101223-3
FIGURE 1. COP Microcontroller Interface
LM70
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3
Absolute Maximum Ratings
(Note 1)
Supply Voltage
-0.3V to 6.0V
Voltage at any Pin
-0.3V to V
+
+ 0.3V
Input Current at any Pin (Note 2)
5 mA
Package Input Current (Note 2)
20 mA
Storage Temperature
-65C to +150C
Soldering Information, Lead Temperature
MSOP-8 and LLP-8 Packages
(Note 3)
Vapor Phase (60 seconds)
Infrared (15 seconds)
215C
220C
ESD Susceptibility (Note 4)
Human Body Model
3000V
Machine Model
300V
Operating Ratings
Specified Temperature Range
T
MIN
to T
MAX
(Note 5)
-55C to +150C
Supply Voltage Range (+V
S
)
+2.65V to +5.5V
Temperature-to-Digital Converter Characteristics
Unless otherwise noted, these specifications apply for V
+
= 2.65V to 3.6V for the LM70-3 and V
+
= 4.5V to 5.5V for the LM70-5
(Note 6). Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
=+25C, unless otherwise noted.
Parameter
Conditions
Typical
(Note 7)
LM70-5
Limits
(Note 8)
LM70-3
Limits
(Note 8)
Units
(Limit)
Temperature Error (Note 6)
T
A
= -10C to +65C
+1.5/-2.0
+1.5/-2.0
C (max)
T
A
= -40C to +85C
2.0
2.0
C (max)
T
A
= -55C to +125C
+3.0/-2.0
+3.0/-2.0
C (max)
T
A
= -55C to +150C
+3.5/-2.0
+3.5/-2.0
C (max)
Resolution
11
0.25
Bits
C
Temperature Conversion Time
(Note 9)
140
210
210
ms (max)
Quiescent Current
Serial Bus Inactive
260
490
490
A (max)
Serial Bus Active
260
A
Shutdown Mode
12
A
Logic Electrical Characteristics
DIGITAL DC CHARACTERISTICS
Unless otherwise noted, these specifications apply for V
+
= 2.65V to 3.6V for the LM70-3 and V
+
= 4.5V to 5.5V for the
LM70-5. 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)
V
IN(1)
Logical "1" Input Voltage
V
+
x 0.7
V (min)
V
+
+ 0.3
V (max)
V
IN(0)
Logical "0" Input Voltage
-0.3
V (min)
V
+
x 0.3
V (max)
Input Hysteresis Voltage
V
+
= 2.65V to 3.6V
0.8
0.27
V (min)
V
+
= 4.5V to 5.5V
0.8
0.35
V (min)
I
IN(1)
Logical "1" Input Current
V
IN
= V
+
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
2.4
V (min)
V
OL
Low Level Output Voltage
I
OL
= +2 mA
0.4
V (max)
I
O_TRI-STATE
TRI-STATE Output Leakage
Current
V
O
= GND
V
O
= V
+
-1
+1
A (min)
A(max)
LM70
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4
Logic Electrical Characteristics
(Continued)
SERIAL BUS DIGITAL SWITCHING CHARACTERISTICS
Unless otherwise noted, these specifications apply for V
+
= 2.65V to 3.6V for the LM70-3 and V
+
= 4.5V to 5.5V for the
LM70-5, 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 (max)
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 (min)
t
6
SC (Clock) High to Data In (SI) Hold Time
60
ns (min)
t
7
Data In (SI) Set-Up Time to SC (Clock) High
30
ns (min)
DS101223-4
FIGURE 2. Data Output Timing Diagram
DS101223-5
FIGURE 3. TRI-STATE Data Output Timing Diagram
DS101223-6
FIGURE 4. Data Input Timing Diagram
LM70
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