October 1999
LM20
2.4V, 10µA, SC70, micro SMD Temperature Sensor
General Description
The LM20 is a precision analog output CMOS integrated-circuit temperature sensor that operates over a −55ÊC to +130ÊC temperature range. The power supply operating range is +2.4 V to +5.5 V. The transfer function of LM20 is predominately linear, yet has a slight predictable parabolic curvature. The accuracy of the LM20 when specified to a parabolic transfer function is ±1.5ÊC at an ambient temperature of +30ÊC. The temperature error increases linearly and reaches a maximum of ±2.5ÊC at the temperature range extremes. The temperature range is affected by the power supply voltage. At a power supply voltage of 2.7 V to 5.5 V the temperature range extremes are +130ÊC and −55ÊC. Decreasing the power supply voltage to 2.4 V changes the negative extreme to −30ÊC, while the positive remains at +130ÊC.
The LM20's quiescent current is less than 10 µA. Therefore, self-heating is less than 0.02ÊC in still air. Shutdown capability for the LM20 is intrinsic because its inherent low power consumption allows it to be powered directly from the output of many logic gates or does not necessitate shutdown at all.
Applications
nCellular Phones
nComputers
nPower Supply Modules
nBattery Management
nFAX Machines
nPrinters
nHVAC
nDisk Drives
nAppliances
Features
nRated for full −55ÊC to +130ÊC range
nAvailable in an SC70 and a micro SMD package
nPredictable curvature error
nSuitable for remote applications
Key Specifications
n Accuracy at +30ÊC |
±1.5 to ±4 ÊC (max) |
n Accuracy at +130ÊC & −55ÊC |
±2.5 to ±5 ÊC (max) |
n Power Supply Voltage Range |
+2.4V to +5.5V |
n Current Drain |
10 µA (max) |
n Nonlinearity |
±0.4 % (typ) |
n Output Impedance |
160 Ω (max) |
n Load Regulation |
|
0 µA < IL< +16 µA |
−2.5 mV (max) |
Typical Application
Output Voltage vs Temperature
DS100908-2
VO = (−3.88x10 −6 xT2) + (−1.15x10 −2 xT) + 1.8639
or
where:
T is temperature, and VO is the measured output voltage of the LM20.
DS100908-24
Full-Range Celsius (Centigrade) Temperature Sensor (−55ÊC to +130ÊC)
Operating from a Single Li-Ion Battery Cell
Sensor Temperature SMD micro SC70, 10µA, 4V,.2 LM20
© 1999 National Semiconductor Corporation |
DS100908 |
www.national.com |
LM20
Typical Application (Continued)
Temperature (T) |
Typical VO |
+130ÊC |
+303 mV |
|
|
+100ÊC |
+675 mV |
|
|
+80ÊC |
+919 mV |
|
|
+30ÊC |
+1515 mV |
|
|
Connection Diagrams
SC70-5
DS100908-1
Note:
-GND (pin 2) may be grounded or left floating. For optimum thermal conductivity to the pc board ground plane pin 2 should be grounded.
-NC (pin 1) should be left floating or grounded. Other signal traces should not be connected to this pin.
Top View
See NS Package Number MAA05A
Temperature (T) |
Typical VO |
+25ÊC |
+1574 mV |
|
|
0ÊC |
+1863.9 mV |
|
|
−30ÊC |
+2205 mV |
|
|
−40ÊC |
+2318 mV |
|
|
−55ÊC |
+2485 mV |
|
|
micro SMD
DS100908-32
Note:
-Pin numbers are referenced to the package marking text orientation.
-Reference JEDEC Registration MO-211, variation BA
-The actual physical placement of package marking will vary slightly from part to part. The package marking will designate the date code and will vary considerably. Package marking does not correlate to device type in any way.
Top View
See NS Package Number BPA04DDC
Ordering Information
Order |
Temperature |
Temperature |
NS Package |
Device |
|
Number |
Accuracy |
Range |
Number |
Marking |
Transport Media |
|
|
|
|
|
|
LM20BIM7 |
±2.5ÊC |
−55ÊC to +130ÊC |
MAA05A |
T2B |
1000 Units on Tape and Reel |
|
|
|
|
|
|
LM20BIM7X |
±2.5ÊC |
−55ÊC to +130ÊC |
MAA05A |
T2B |
3000 Units on Tape and Reel |
|
|
|
|
|
|
LM20CIM7 |
±5ÊC |
−55ÊC to +130ÊC |
MAA05A |
T2C |
1000 Units on Tape and Reel |
|
|
|
|
|
|
LM20CIM7X |
±5ÊC |
−55ÊC to +130ÊC |
MAA05A |
T2C |
3000 Units on Tape and Reel |
|
|
|
|
|
|
LM20SIBP |
±3.5ÊC |
−40ÊC to +125ÊC |
BPA04DDC |
Date |
250 Units on Tape and Reel |
|
|
|
|
Code |
|
|
|
|
|
|
|
LM20SIBPX |
±3.5ÊC |
−40ÊC to +125ÊC |
BPA04DDC |
Date |
3000 Units on Tape and Reel |
|
|
|
|
Code |
|
|
|
|
|
|
|
www.national.com |
2 |
Absolute Maximum Ratings (Note 1)
Supply Voltage |
+6.5V to −0.2V |
Output Voltage |
(V+ + 0.6 V) to |
|
−0.6 V |
Output Current |
10 mA |
Input Current at any pin (Note 2) |
5 mA |
Storage Temperature |
−65ÊC to +150ÊC |
Maximum Junction Temperature (TJMAX) |
+150ÊC |
ESD Susceptibility (Note 3) : |
|
Human Body Model |
2500 V |
Machine Model |
250 V |
Lead Temperature |
|
SC-70 Package (Note 4) : |
|
Vapor Phase (60 seconds) |
+215ÊC |
Infrared (15 seconds) |
+220ÊC |
Operating Ratings(Note 1)
Specified Temperature Range: |
TMIN ≤ TA ≤ TMAX |
|
LM20B, LM20C with |
|
|
2.4 V ≤ V+≤ 2.7 V |
−30ÊC |
≤ TA ≤ +130ÊC |
LM20B, LM20C with |
|
|
2.7 V ≤ V+≤ 5.5 V |
−55ÊC |
≤ TA ≤ +130ÊC |
LM20S with |
|
|
2.4 V ≤ V+≤ 5.5 V |
−30ÊC |
≤ TA ≤ +125ÊC |
LM20S with |
|
|
2.7 V ≤ V+≤ 5.5 V |
−40ÊC |
≤ TA ≤ +125ÊC |
Supply Voltage Range (V+) |
+2.4 V to +5.5 V |
|
Thermal Resistance, θJA(Note 5) |
|
415ÊC/W |
SC-70 |
|
|
micro SMD |
|
TBDÊC/W |
Electrical Characteristics
Unless otherwise noted, these specifications apply for V+ = +2.7 VDC. Boldface limits apply for TA = TJ = TMIN to TMAX ; all other limits TA = TJ = 25ÊC; Unless otherwise noted.
Parameter |
|
Conditions |
Typical |
LM20B |
LM20C |
LM20S |
Units |
|
|
|
(Note 6) |
|
|
|
(Limit) |
|
|
|
Limits |
Limits |
Limits |
||
|
|
|
|
|
|||
|
|
|
|
(Note 7) |
(Note 7) |
(Note 7) |
|
|
|
|
|
|
|
|
|
Temperature to Voltage Error |
TA = +25ÊC to +30ÊC |
|
±1.5 |
±4.0 |
±2.5 |
ÊC (max) |
|
VO = (−3.88x10 −6 xT2) |
TA = +130ÊC |
|
± 2.5 |
± 5.0 |
|
ÊC (max) |
|
+ (−1.15x10 −2 xT) + 1.8639V |
TA = +125ÊC |
|
± 2.5 |
± 5.0 |
± 3.5 |
ÊC (max) |
|
(Note 8) |
|
||||||
TA = +100ÊC |
|
± 2.2 |
± 4.7 |
± 3.2 |
ÊC (max) |
||
|
|
||||||
|
TA = +85ÊC |
|
± 2.1 |
± 4.6 |
± 3.1 |
ÊC (max) |
|
|
TA = +80ÊC |
|
± 2.0 |
± 4.5 |
± 3.0 |
ÊC (max) |
|
|
TA = 0ÊC |
|
± 1.9 |
± 4.4 |
± 2.9 |
ÊC (max) |
|
|
TA = −30ÊC |
|
± 2.2 |
± 4.7 |
± 3.3 |
ÊC (min) |
|
|
TA = −40ÊC |
|
± 2.3 |
± 4.8 |
± 3.5 |
ÊC (max) |
|
|
TA = −55ÊC |
|
± 2.5 |
± 5.0 |
|
ÊC (max) |
|
Output Voltage at 0ÊC |
|
|
+1.8639 |
|
|
|
V |
|
|
|
|
|
|
|
|
Variance from Curve |
|
|
±1.0 |
|
|
|
ÊC |
|
|
|
|
|
|
|
|
Non-Linearity (Note 9) |
−20ÊC |
≤ TA ≤ +80ÊC |
±0.4 |
|
|
|
% |
Sensor Gain (Temperature |
−30ÊC |
≤ TA ≤ +100ÊC |
−11.77 |
−11.4 |
−11.0 |
−11.0 |
mV/ÊC (min) |
Sensitivity or Average Slope) |
|
|
|
−12.2 |
−12.6 |
−12.6 |
mV/ÊC (max) |
to equation: |
|
|
|
|
|
|
|
VO=−11.77 mV/ÊCxT+1.860V |
|
|
|
|
|
|
|
Output Impedance |
0 µA ≤ IL ≤ +16 µA(Notes |
|
160 |
160 |
160 |
Ω (max) |
|
|
11, 12) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Load Regulation(Note 10) |
0 µA ≤ IL ≤ +16 µA(Notes |
|
−2.5 |
−2.5 |
−2.5 |
mV (max) |
|
|
11, 12) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Line Regulation |
+2. 4 V ≤ V+ ≤ +5.0V |
|
+3.3 |
+3.7 |
+3.7 |
mV/V (max) |
|
|
+5.0 V ≤ V+ ≤ +5.5 V |
|
+8.8 |
+8.9 |
+8.9 |
mV (max) |
|
Quiescent Current |
+2. 4 V ≤ V+ ≤ +5.5V |
4.5 |
7 |
7 |
7 |
µA (max) |
|
|
+2. 4 V ≤ V+ ≤ +5.0V |
4.5 |
10 |
10 |
10 |
µA (max) |
|
Change of Quiescent Current |
+2. 4 V ≤ V+ ≤ +5.5V |
+0.7 |
|
|
|
µA |
|
Temperature Coefficient of |
|
|
−11 |
|
|
|
nA/ÊC |
Quiescent Current |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Shutdown Current |
V+ ≤ +0.8 V |
0.02 |
|
|
|
µA |
|
LM20
3 |
www.national.com |
Loading...