LM26LVCISD-080 [NSC]
1.6 V, LLP-6 Factory Preset Temperature Switch and Temperature Sensor; 1.6 V， LLP - 6出厂预设温度开关和温度传感器
| 型号： | LM26LVCISD-080 |
| 厂家： | 
National Semiconductor |
| 描述： | 1.6 V, LLP-6 Factory Preset Temperature Switch and Temperature Sensor |
| 文件： | 总20页 (文件大小：546K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
May 16, 2008
LM26LV
1.6 V, LLP-6 Factory Preset Temperature Switch and
Temperature Sensor
Automotive
■
■
■
■
General Description
Disk Drives
The LM26LV is a low-voltage, precision, dual-output, low-
Games
power temperature switch and temperature sensor. The tem-
perature trip point (TTRIP) can be preset at the factory to any
temperature in the range of 0°C to 150°C in 1°C increments.
Built-in temperature hysteresis (THYST) keeps the output sta-
ble in an environment of temperature instability.
Appliances
Features
Low 1.6V operation
■
■
■
■
■
■
■
■
In normal operation the LM26LV temperature switch outputs
assert when the die temperature exceeds TTRIP. The temper-
ature switch outputs will reset when the temperature falls
Low quiescent current
Push-pull and open-drain temperature switch outputs
Wide trip point range of 0°C to 150°C
below
a temperature equal to (TTRIP − THYST). The
OVERTEMP digital output, is active-high with a push-pull
structure, while the OVERTEMP digital output, is active-low
with an open-drain structure.
Very linear analog VTEMP temperature sensor output
VTEMP output short-circuit protected
Accurate over −50°C to 150°C temperature range
An analog output, VTEMP, delivers an analog output voltage
which is inversely proportional to the measured temperature.
2.2 mm by 2.5 mm (typ) LLP-6 package
Excellent power supply noise rejection
■
Driving the TRIP TEST input high: (1) causes the digital out-
puts to be asserted for in-situ verification and, (2) causes the
threshold voltage to appear at the VTEMP output pin, which
could be used to verify the temperature trip point.
Key Specifications
■ Supply Voltage
■ Supply Current
■ Accuracy, Trip Point
Temperature
1.6V to 5.5V
The LM26LV's low minimum supply voltage makes it ideal for
1.8 Volt system designs. Its wide operating range, low supply
current , and excellent accuracy provide a temperature switch
solution for a wide range of commercial and industrial appli-
cations.
8 μA (typ)
0°C to 150°C
±2.2°C
0°C to 150°C
0°C to 120°C
−50°C to 0°C
±2.3°C
±2.2°C
±1.7°C
■ Accuracy, VTEMP
Applications
Cell phones
■
■
■
■
■ VTEMP Output Drive
■ Operating Temperature
■ Hysteresis Temperature
±100 μA
Wireless Transceivers
−50°C to 150°C
4.5°C to 5.5°C
Digital Cameras
Personal Digital Assistants (PDA's)
Battery Management
■
Connection Diagram
Typical Transfer Characteristic
LLP-6
VTEMP Analog Voltage vs Die Temperature
20204701
Top View
See NS Package Number SDB06A
20204724
© 2008 National Semiconductor Corporation
202047
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Block Diagram
20204703
Pin Descriptions
Pin
Name
No.
Type Equivalent Circuit
Description
TRIP TEST pin. Active High input.
If TRIP TEST = 0 (Default) then:
VTEMP = VTS, Temperature Sensor Output Voltage
If TRIP TEST = 1 then:
OVERTEMP and OVERTEMP outputs are asserted and
VTEMP = VTRIP, Temperature Trip Voltage.
This pin may be left open if not used.
TRIP
TEST
Digital
Input
1
Over Temperature Switch output
Active High, Push-Pull
Digital
Output
5
3
6
OVERTEMP
OVERTEMP
VTEMP
Asserted when the measured temperature exceeds the Trip
Point Temperature or if TRIP TEST = 1
This pin may be left open if not used.
Over Temperature Switch output
Active Low, Open-drain (See Section 2.1 regarding required pull-
up resistor.)
Asserted when the measured temperature exceeds the Trip
Point Temperature or if TRIP TEST = 1
This pin may be left open if not used.
Digital
Output
VTEMP Analog Voltage Output
If TRIP TEST = 0 then
VTEMP = VTS, Temperature Sensor Output Voltage
If TRIP TEST = 1 then
Analog
Output
VTEMP = VTRIP, Temperature Trip Voltage
This pin may be left open if not used.
VDD
Positive Supply Voltage
Power Supply Ground
4
2
Power
GND
Ground
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2
Typical Application
20204702
3
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Ordering Information
Temperature Trip
NS Package
Number
Order Number
Top Mark
Transport Media
Point, °C
150°C
150°C
145°C
145°C
140°C
140°C
135°C
135°C
130°C
130°C
125°C
125°C
120°C
120°C
115°C
115°C
110°C
110°C
105°C
105°C
100°C
100°C
95°C
LM26LVCISD-150
LM26LVCISDX-150
LM26LVCISD-145
LM26LVCISDX-145
LM26LVCISD-140
LM26LVCISDX-140
LM26LVCISD-135
LM26LVCISDX-135
LM26LVCISD-130
LM26LVCISDX-130
LM26LVCISD-125
LM26LVCISDX-125
LM26LVCISD-120
LM26LVCISDX-120
LM26LVCISD-115
LM26LVCISDX-115
LM26LVCISD-110
LM26LVCISDX-110
LM26LVCISD-105
LM26LVCISDX-105
LM26LVCISD-100
LM26LVCISDX-100
LM26LVCISD-095
LM26LVCISDX-095
LM26LVCISD-090
LM26LVCISDX-090
LM26LVCISD-085
LM26LVCISDX-085
LM26LVCISD-080
LM26LVCISDX-080
LM26LVCISD-075
LM26LVCISDX-075
LM26LVCISD-070
LM26LVCISDX-070
LM26LVCISD-065
LM26LVCISDX-065
LM26LVCISD-060
LM26LVCISDX-060
LM26LVCISD-050
LM26LVCISDX-050
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
SDB06A
150
150
145
145
140
140
135
135
130
130
125
125
120
120
115
115
110
110
105
105
100
100
095
095
090
090
085
085
080
080
075
075
070
070
065
065
060
060
050
050
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
95°C
90°C
90°C
85°C
85°C
80°C
80°C
75°C
75°C
70°C
70°C
65°C
65°C
60°C
60°C
50°C
50°C
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4
Machine Model
Charged Device Model
Soldering process must comply with National's
Reflow Temperature Profile specifications. Refer to
www.national.com/packaging. (Note 4)
300V
1000V
Absolute Maximum Ratings (Note 1)
Supply Voltage
−0.2V to +6.0V
Voltage at OVERTEMP pin
−0.2V to +6.0V
Voltage at OVERTEMP and
VTEMP pins
−0.2V to (VDD + 0.5V)
−0.2V to (VDD + 0.5V)
±7 mA
TRIP TEST Input Voltage
Output Current, any output pin
Input Current at any pin (Note 2)
Storage Temperature
Operating Ratings (Note 1)
Specified Temperature Range:
ꢀTMIN ≤ TA ≤ TMAX
−50°C ≤ TA ≤ +150°C
+1.6 V to +5.5 V
5 mA
−65°C to +150°C
LM26LV
Supply Voltage Range (VDD
)
Maximum Junction Temperature
TJ(MAX)
Thermal Resistance (θJA) (Note 5)
LLP-6 (Package SDB06A)
+155°C
4500V
152 °C/W
ESD Susceptibility (Note 3) :
Human Body Model
Accuracy Characteristics
Trip Point Accuracy
Limits
(Note 7)
Units
(Limit)
Parameter
Conditions
VDD = 5.0 V
Trip Point Accuracy (Note 8)
0 − 150°C
±2.2
°C (max)
VTEMP Analog Temperature Sensor Output Accuracy
There are four gains corresponding to each of the four Temperature Trip Point Ranges. Gain 1 is the sensor gain used for Tem-
perature Trip Point 0 - 69°C. Likewise Gain 2 is for Trip Points 70 - 109 °C; Gain 3 for 110 - 129 °C; and Gain 4 for 130 - 150 °C.
These limits do not include DC load regulation. These stated accuracy limits are with reference to the values in the LM26LV
Conversion Table.
Limits
(Note 7)
Units
(Limit)
Parameter
Conditions
TA = 20°C to 40°C
TA = 0°C to 70°C
TA = 0°C to 90°C
TA = 0°C to 120°C
TA = 0°C to 150°C
TA = −50°C to 0°C
TA = 20°C to 40°C
TA = 0°C to 70°C
TA = 0°C to 90°C
TA = 0°C to 120°C
TA = 0°C to 150°C
TA = −50°C to 0°C
TA = 20°C to 40°C
TA = 0°C to 70°C
TA = 0°C to 90°C
TA = 0°C to 120°C
TA = 0°C to 150°C
TA = −50°C to 0°C
TA = 20°C to 40°C
TA = 0°C to 70°C
TA = 0°C to 90°C
TA = 0°C to 120°C
TA = 0°C to 150°C
TA = −50°C to 0°C
VDD = 1.6 to 5.5 V
VDD = 1.6 to 5.5 V
VDD = 1.6 to 5.5 V
VDD = 1.6 to 5.5 V
VDD = 1.6 to 5.5 V
VDD = 1.7 to 5.5 V
VDD = 1.8 to 5.5 V
VDD = 1.9 to 5.5 V
VDD = 1.9 to 5.5 V
VDD = 1.9 to 5.5 V
VDD = 1.9 to 5.5 V
VDD = 2.3 to 5.5 V
VDD = 2.3 to 5.5 V
VDD = 2.5 to 5.5 V
VDD = 2.5 to 5.5 V
VDD = 2.5 to 5.5 V
VDD = 2.5 to 5.5 V
VDD = 3.0 to 5.5 V
VDD = 2.7 to 5.5 V
VDD = 3.0 to 5.5 V
VDD = 3.0 to 5.5 V
VDD = 3.0 to 5.5 V
VDD = 3.0 to 5.5 V
VDD = 3.6 to 5.5 V
±1.8
±2.0
±2.1
±2.2
±2.3
±1.7
±1.8
±2.0
±2.1
±2.2
±2.3
±1.7
±1.8
±2.0
±2.1
±2.2
±2.3
±1.7
±1.8
±2.0
±2.1
±2.2
±2.3
±1.7
Gain 1: for Trip Point
Range 0 - 69°C
°C (max)
°C (max)
°C (max)
Gain 2: for Trip Point
Range 70 - 109°C
VTEMP Temperature
Accuracy
(Note 8)
Gain 3: for Trip Point
Range 110 - 129°C
Gain 4: for Trip Point
Range 130 - 150°C
°C (max)
5
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Electrical Characteristics
Unless otherwise noted, these specifications apply for +VDD = +1.6V to +5.5V. Boldface limits apply for TA = TJ = TMIN to
TMAX ; all other limits TA = TJ = 25°C.
Symbol Parameter
Conditions
Typical
Limits
Units
(Limit)
(Note 6)
(Note 7)
GENERAL SPECIFICATIONS
IS
Quiescent Power Supply
Current
8
5
16
μA (max)
5.5
4.5
°C (max)
°C (Min)
Hysteresis
OVERTEMP DIGITAL OUTPUT
ACTIVE HIGH, PUSH-PULL
VDD ≥ 1.6V
VDD ≥ 2.0V
VDD ≥ 3.3V
VDD ≥ 1.6V
VDD ≥ 2.0V
VDD ≥ 3.3V
Source ≤ 340 μA
VDD − 0.2V
V (min)
V (min)
Source ≤ 498 μA
Source ≤ 780 μA
Source ≤ 600 μA
Source ≤ 980 μA
Source ≤ 1.6 mA
VOH
Logic "1" Output Voltage
VDD − 0.45V
BOTH OVERTEMP and OVERTEMP DIGITAL OUTPUTS
VDD ≥ 1.6V
VDD ≥ 2.0V
VDD ≥ 3.3V
Sink ≤ 385 μA
Sink ≤ 500 μA
Sink ≤ 730 μA
Sink ≤ 690 μA
Sink ≤ 1.05 mA
Sink ≤ 1.62 mA
0.2
VOL
Logic "0" Output Voltage
V (max)
VDD ≥ 1.6V
VDD ≥ 2.0V
VDD ≥ 3.3V
0.45
OVERTEMP DIGITAL OUTPUT
ACTIVE LOW, OPEN DRAIN
TA = 30 °C
0.001
0.025
Logic "1" Output Leakage
IOH
1
μA (max)
Current (Note 12)
TA = 150 °C
VTEMP ANALOG TEMPERATURE SENSOR OUTPUT
Gain 1: If Trip Point = 0 - 69°C
−5.1
−7.7
mV/°C
mV/°C
mV/°C
mV/°C
Gain 2: If Trip Point = 70 - 109°C
Gain 3: If Trip Point = 110 - 129°C
Gain 4: If Trip Point = 130 - 150°C
VTEMP Sensor Gain
−10.3
−12.8
Source ≤ 90 μA
(VDD − VTEMP) ≥ 200 mV
−0.1
0.1
−1
1
mV (max)
mV (max)
mV (max)
mV (max)
1.6V ≤ VDD < 1.8V
Sink ≤ 100 μA
VTEMP ≥ 260 mV
VTEMP Load Regulation
(Note 10)
Source ≤ 120 μA
(VDD − VTEMP) ≥ 200 mV
−0.1
0.1
−1
1
VDD ≥ 1.8V
Sink ≤ 200 μA
VTEMP ≥ 260 mV
1
Ohm
mV
Source or Sink = 100 μA
0.29
74
VDD Supply- to-VTEMP
DC Line Regulation
(Note 13)
VDD = +1.6V to +5.5V
μV/V
dB
−82
VTEMP Output Load
Capacitance
CL
Without series resistor. See Section 4.2
1100
pF (max)
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6
Electrical Characteristics
Unless otherwise noted, these specifications apply for +VDD = +1.6V to +5.5V. Boldface limits apply for TA = TJ = TMIN to
TMAX ; all other limits TA = TJ = 25°C.
Symbol Parameter
Conditions
Typical
Limits
Units
(Limit)
(Note 6)
(Note 7)
TRIP TEST DIGITAL INPUT
VIH
VIL
IIH
VDD− 0.5
0.5
Logic "1" Threshold Voltage
Logic "0" Threshold Voltage
Logic "1" Input Current
V (min)
V (max)
μA (max)
1.5
2.5
Logic "0" Input Current
(Note 12)
IIL
0.001
1
μA (max)
TIMING
Time from Power On to Digital
Output Enabled. See
definition below.
tEN
1.1
0.9
2.3
10
ms (max)
ms (max)
(Note 11).
Time from Power On to
Analog Temperature Valid.
See definition below.
(Note 11)
t
VTEMP
Definitions of tEN and tV
TEMP
20204751
20204750
7
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Notes
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed
specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test
conditions.
Note 2: When the input voltage (VI) at any pin exceeds power supplies (VI < GND or VI > VDD), the current at that pin should be limited to 5 mA.
Note 3: The Human Body Model (HBM) is a 100 pF capacitor charged to the specified voltage then discharged through a 1.5 kΩ resistor into each pin. The
Machine Model (MM) is a 200 pF capacitor charged to the specified voltage then discharged directly into each pin. The Charged Device Model (CDM) is a specified
circuit characterizing an ESD event that occurs when a device acquires charge through some triboelectric (frictional) or electrostatic induction processes and then
abruptly touches a grounded object or surface.
Note 4: Reflow temperature profiles are different for lead-free and non-lead-free packages.
Note 5: The junction to ambient temperature resistance (θJA) is specified without a heat sink in still air.
Note 6: Typicals are at TJ = TA = 25°C and represent most likely parametric norm.
Note 7: Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 8: Accuracy is defined as the error between the measured and reference output voltages, tabulated in the Conversion Table at the specified conditions of
supply gain setting, voltage, and temperature (expressed in °C). Accuracy limits include line regulation within the specified conditions. Accuracy limits do not
include load regulation; they assume no DC load.
Note 9: Changes in output due to self heating can be computed by multiplying the internal dissipation by the temperature resistance.
Note 10: Source currents are flowing out of the LM26LV. Sink currents are flowing into the LM26LV.
Note 11: Guaranteed by design.
Note 12: The 1 µA limit is based on a testing limitation and does not reflect the actual performance of the part. Expect to see a doubling of the current for every
15°C increase in temperature. For example, the 1 nA typical current at 25°C would increase to 16 nA at 85°C.
Note 13: Line regulation (DC) is calculated by subtracting the output voltage at the highest supply voltage from the output voltage at the lowest supply voltage.
The typical DC line regulation specification does not include the output voltage shift discussed in Section 4.3.
Note 14: The curves shown represent typical performance under worst-case conditions. Performance improves with larger overhead (VDD − VTEMP), larger VDD
,
and lower temperatures.
Note 15: The curves shown represent typical performance under worst-case conditions. Performance improves with larger VTEMP, larger VDD and lower
temperatures.
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Typical Performance Characteristics
VTEMP Output Temperature Error vs. Temperature
Minimum Operating Temperature vs. Supply Voltage
20204706
20204707
Supply Current vs. Temperature
Supply Current vs. Supply Voltage
20204704
20204705
Load Regulation, 100 mV Overhead
T = 80°C Sourcing Current (Note 14)
Load Regulation, 200 mV Overhead
T = 80°C Sourcing Current (Note 14)
20204740
20204746
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Load Regulation, 400 mV Overhead
T = 80°C Sourcing Current (Note 14)
Load Regulation, 1.72V Overhead
T = 150°C, VDD = 2.4V
Sourcing Current (Note 14)
20204747
20204748
Load Regulation, VDD = 1.6V
Sinking Current (Note 15)
Load Regulation, VDD = 1.8V
Sinking Current (Note 15)
20204741
20204744
Load Regulation, VDD = 2.4V
Change in VTEMP vs. Overhead Voltage
Sinking Current (Note 15)
20204742
20204745
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VTEMP Supply-Noise Gain vs. Frequency
VTEMP vs. Supply Voltage
Gain 1: For Trip Points
0 - 69°C
20204743
20204734
VTEMP vs. Supply Voltage
Gain 2: For Trip Points
70 - 109°C
VTEMP vs. Supply Voltage
Gain 3: For Trip Points
110 - 129°C
20204735
20204736
VTEMP vs. Supply Voltage
Gain 4: For Trip Points
130 - 150°C
20204737
11
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−22
−21
−20
−19
−18
−17
−16
−15
−14
−13
−12
−11
−10
−9
−8
−7
−6
−5
−4
−3
−2
−1
0
1172
1167
1162
1157
1152
1147
1142
1137
1132
1127
1122
1116
1111
1106
1101
1096
1091
1086
1081
1076
1071
1066
1061
1056
1051
1046
1041
1035
1030
1025
1020
1015
1010
1005
1000
995
1757
1750
1742
1735
1727
1720
1712
1705
1697
1690
1682
1674
1667
1659
1652
1644
1637
1629
1621
1614
1606
1599
1591
1583
1576
1568
1561
1553
1545
1538
1530
1522
1515
1507
1499
1492
1484
1477
1469
1461
1454
1446
1438
1431
1423
1415
1407
1400
1392
1384
1377
2343
2333
2323
2313
2303
2293
2283
2272
2262
2252
2242
2232
2222
2212
2202
2192
2182
2171
2161
2151
2141
2131
2121
2111
2101
2090
2080
2070
2060
2050
2040
2029
2019
2009
1999
1989
1978
1968
1958
1948
1938
1927
1917
1907
1897
1886
1876
1866
1856
1845
1835
2929
2916
2903
2891
2878
2866
2853
2841
2828
2815
2803
2790
2777
2765
2752
2740
2727
2714
2702
2689
2676
2664
2651
2638
2626
2613
2600
2587
2575
2562
2549
2537
2524
2511
2498
2486
2473
2460
2447
2435
2422
2409
2396
2383
2371
2358
2345
2332
2319
2307
2294
1.0 LM26LV VTEMP vs Die
Temperature Conversion Table
The LM26LV has one out of four possible factory-set gains,
Gain 1 through Gain 4, depending on the range of the Tem-
perature Trip Point. The VTEMP temperature sensor voltage,
in millivolts, at each discrete die temperature over the com-
plete operating temperature range, and for each of the four
Temperature Trip Point ranges, is shown in the Conversion
Table below. This table is the reference from which the
LM26LV accuracy specifications (listed in the Electrical Char-
acteristics section) are determined. This table can be used,
for example, in a host processor look-up table. See Section
1.1.1 for the parabolic equation used in the Conversion Table.
VTEMP Temperature Sensor Output Voltage vs Die
Temperature Conversion Table
The VTEMP temperature sensor output voltage, in mV, vs Die
Temperature, in °C, for each of the four gains corresponding
to each of the four Temperature Trip Point Ranges. Gain 1 is
the sensor gain used for Temperature Trip Point 0 - 69°C.
Likewise Gain 2 is for Trip Points 70 - 109 °C; Gain 3 for 110
- 129 °C; and Gain 4 for 130 - 150 °C. VDD = 5.0V. The values
in bold font are for the Trip Point range.
VTEMP, Analog Output Voltage, mV
Die
Temp.,
°C
Gain 1:
for
Gain 2:
for
Gain 3:
for
TTRIP
Gain 4:
for
TTRIP =
TTRIP
=
TTRIP
=
=
0-69°C 70-109°C 110-129°C 130-150°C
1
−50
−49
−48
−47
−46
−45
−44
−43
−42
−41
−40
−39
−38
−37
−36
−35
−34
−33
−32
−31
−30
−29
−28
−27
−26
−25
−24
−23
1312
1307
1302
1297
1292
1287
1282
1277
1272
1267
1262
1257
1252
1247
1242
1237
1232
1227
1222
1217
1212
1207
1202
1197
1192
1187
1182
1177
1967
1960
1952
1945
1937
1930
1922
1915
1908
1900
1893
1885
1878
1870
1863
1855
1848
1840
1833
1825
1818
1810
1803
1795
1788
1780
1773
1765
2623
2613
2603
2593
2583
2573
2563
2553
2543
2533
2523
2513
2503
2493
2483
2473
2463
2453
2443
2433
2423
2413
2403
2393
2383
2373
2363
2353
3278
3266
3253
3241
3229
3216
3204
3191
3179
3166
3154
3141
3129
3116
3104
3091
3079
3066
3054
3041
3029
3016
3004
2991
2979
2966
2954
2941
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
990
985
980
974
969
964
959
954
949
944
939
934
928
923
918
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12
29
30
31
32
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37
38
39
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49
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64
65
66
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68
69
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71
72
73
74
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76
77
78
79
913
908
903
898
892
887
882
877
872
867
862
856
851
846
841
836
831
825
820
815
810
805
800
794
789
784
779
774
769
763
758
753
748
743
737
732
727
722
717
711
706
701
696
690
685
680
675
670
664
659
654
1369
1361
1354
1346
1338
1331
1323
1315
1307
1300
1292
1284
1276
1269
1261
1253
1245
1238
1230
1222
1214
1207
1199
1191
1183
1176
1168
1160
1152
1144
1137
1129
1121
1113
1105
1098
1090
1082
1074
1066
1059
1051
1043
1035
1027
1019
1012
1004
996
1825
1815
1804
1794
1784
1774
1763
1753
1743
1732
1722
1712
1701
1691
1681
1670
1660
1650
1639
1629
1619
1608
1598
1588
1577
1567
1557
1546
1536
1525
1515
1505
1494
1484
1473
1463
1453
1442
1432
1421
1411
1400
1390
1380
1369
1359
1348
1338
1327
1317
1306
2281
2268
2255
2242
2230
2217
2204
2191
2178
2165
2152
2139
2127
2114
2101
2088
2075
2062
2049
2036
2023
2010
1997
1984
1971
1958
1946
1933
1920
1907
1894
1881
1868
1855
1842
1829
1816
1803
1790
1776
1763
1750
1737
1724
1711
1698
1685
1672
1659
1646
1633
80
81
649
643
638
633
628
622
617
612
607
601
596
591
586
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564
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972
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1180
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1128
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1096
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1043
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1011
1001
990
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998
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130
979
969
958
948
937
926
916
905
894
884
873
862
852
841
831
820
809
798
788
985
988
777
971
980
766
958
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linear formula below can be used. Using this formula, with the
constant and slope in the following set of equations, the best-
fit VTEMP vs Die Temperature performance can be calculated
with an approximation error less than 18 mV. VTEMP is in mV.
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
379
373
368
362
357
352
346
341
336
330
325
320
314
309
303
298
293
287
282
277
567
559
551
543
535
527
519
511
503
495
487
479
471
463
455
447
438
430
422
414
756
745
734
724
713
702
691
681
670
659
649
638
627
616
606
595
584
573
562
552
945
931
918
904
891
878
864
851
837
824
811
797
784
770
757
743
730
716
703
690
1.1.3 First-Order Approximation (Linear) over Small
Temperature Range
For a linear approximation, a line can easily be calculated
over the desired temperature range from the Conversion Ta-
ble using the two-point equation:
Where V is in mV, T is in °C, T1 and V1 are the coordinates of
the lowest temperature, T2 and V2 are the coordinates of the
highest temperature.
For example, if we want to determine the equation of a line
with Gain 4, over a temperature range of 20°C to 50°C, we
would proceed as follows:
1.1 VTEMP vs DIE TEMPERATURE APPROXIMATIONS
The LM26LV's VTEMP analog temperature output is very lin-
ear. The Conversion Table above and the equation in Section
1.1.1 represent the most accurate typical performance of the
VTEMP voltage output vs Temperature.
1.1.1 The Second-Order Equation (Parabolic)
The data from the Conversion Table, or the equation below,
when plotted, has an umbrella-shaped parabolic curve.
VTEMP is in mV.
Using this method of linear approximation, the transfer func-
tion can be approximated for one or more temperature ranges
of interest.
1.1.2 The First-Order Approximation (Linear)
For a quicker approximation, although less accurate than the
second-order, over the full operating temperature range the
www.national.com
14
(1) We see that for VOL of 0.2 V the electrical specification for
OVERTEMP shows a maximim isink of 385 µA.
2.0 OVERTEMP and OVERTEMP
Digital Outputs
(2) Let iL= 1 µA, then iT is about 386 µA max. If we select
35 µA as the current limit then iT for the calculation becomes
35 µA
The OVERTEMP Active High, Push-Pull Output and the
OVERTEMP Active Low, Open-Drain Output both assert at
the same time whenever the Die Temperature reaches the
factory preset Temperature Trip Point. They also assert si-
multaneously whenever the TRIP TEST pin is set high. Both
outputs de-assert when the die temperature goes below the
Temperature Trip Point - Hysteresis. These two types of dig-
ital outputs enable the user the flexibility to choose the type
of output that is most suitable for his design.
(3) We notice that VDD(Max) is 3.3V + 0.3V = 3.6V and then
calculate the pull-up resistor as
RPull-up = (3.6 − 0.2)/35 µA = 97k
(4) Based on this calculated value, we select the closest re-
sistor value in the tolerance family we are using.
In our example, if we are using 5% resistor values, then the
next closest value is 100 kΩ.
Either the OVERTEMP or the OVERTEMP Digital Output pins
can be left open if not used.
2.2 NOISE IMMUNITY
The LM26LV is virtually immune from false triggers on the
OVERTEMP and OVERTEMP digital outputs due to noise on
the power supply. Test have been conducted showing that,
with the die temperature within 0.5°C of the temperature trip
point, and the severe test of a 3 Vpp square wave "noise"
signal injected on the VDD line, over the VDD range of 2V to
5V, there were no false triggers.
2.1 OVERTEMP OPEN-DRAIN DIGITAL OUTPUT
The OVERTEMP Active Low, Open-Drain Digital Output, if
used, requires a pull-up resistor between this pin and VDD
The following section shows how to determine the pull-up re-
sistor value.
.
Determining the Pull-up Resistor Value
3.0 TRIP TEST Digital Input
The TRIP TEST pin simply provides a means to test the
OVERTEMP and OVERTEMP digital outputs electronically
by causing them to assert, at any operating temperature, as
a result of forcing the TRIP TEST pin high.
When the TRIP TEST pin is pulled high the VTEMP pin will be
at the VTRIP voltage.
If not used, the TRIP TEST pin may either be left open or
grounded.
4.0 VTEMP Analog Temperature
Sensor Output
The VTEMP push-pull output provides the ability to sink and
source significant current. This is beneficial when, for exam-
ple, driving dynamic loads like an input stage on an analog-
to-digital converter (ADC). In these applications the source
current is required to quickly charge the input capacitor of the
ADC. See the Applications Circuits section for more discus-
sion of this topic. The LM26LV is ideal for this and other
applications which require strong source or sink current.
20204752
The Pull-up resistor value is calculated at the condition of
maximum total current, iT, through the resistor. The total cur-
rent is:
where,
iT
4.1 NOISE CONSIDERATIONS
iT is the maximum total current through the Pull-up
Resistor at VOL
The LM26LV's supply-noise gain (the ratio of the AC signal
on VTEMP to the AC signal on VDD) was measured during
bench tests. It's typical attenuation is shown in the Typical
Performance Characteristics section. A load capacitor on the
output can help to filter noise.
.
iL
iL is the load current, which is very low for typical
digital inputs.
VOUT
VDD(Max)
VOUT is the Voltage at the OVERTEMP pin. Use
VOL for calculating the Pull-up resistor.
For operation in very noisy environments, some bypass ca-
pacitance should be present on the supply within approxi-
mately 2 inches of the LM26LV.
VDD(Max) is the maximum power supply voltage to be
used in the customer's system.
The pull-up resistor maximum value can be found by using
the following formula:
4.2 CAPACITIVE LOADS
The VTEMP Output handles capacitive loading well. In an ex-
tremely noisy environment, or when driving a switched sam-
pling input on an ADC, it may be necessary to add some
filtering to minimize noise coupling. Without any precautions,
the VTEMP can drive a capacitive load less than or equal to
1100 pF as shown in Figure 1. For capacitive loads greater
than 1100 pF, a series resistor is required on the output, as
shown in Figure 2, to maintain stable conditions.
EXAMPLE CALCULATION
Suppose we have, for our example, a VDD of 3.3 V ± 0.3V, a
CMOS digital input as a load, a VOL of 0.2 V.
15
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To ensure good temperature conductivity, the backside of the
LM26LV die is directly attached to the GND pin (Pin 2). The
temperatures of the lands and traces to the other leads of the
LM26LV will also affect the temperature reading.
Alternatively, the LM26LV can be mounted inside a sealed-
end metal tube, and can then be dipped into a bath or screwed
into a threaded hole in a tank. As with any IC, the LM26LV
and accompanying wiring and circuits must be kept insulated
and dry, to avoid leakage and corrosion. This is especially true
if the circuit may operate at cold temperatures where con-
densation can occur. If moisture creates a short circuit from
the VTEMP output to ground or VDD, the VTEMP output from the
LM26LV will not be correct. Printed-circuit coatings are often
used to ensure that moisture cannot corrode the leads or cir-
cuit traces.
20204715
FIGURE 1. LM26LV No Decoupling Required for
Capacitive Loads Less than 1100 pF.
The thermal resistance junction-to-ambient (θJA) is the pa-
rameter used to calculate the rise of a device junction tem-
perature due to its power dissipation. The equation used to
calculate the rise in the LM26LV's die temperature is
20204733
CLOAD
1.1 nF to 99 nF
100 nF to 999 nF
1 μF
RS
3 kΩ
where TA is the ambient temperature, IQ is the quiescent cur-
rent, IL is the load current on the output, and VO is the output
voltage. For example, in an application where TA = 30 °C,
VDD = 5 V, IDD = 9 μA, Gain 4, VTEMP = 2231 mV, and
IL = 2 μA, the junction temperature would be 30.021 °C, show-
ing a self-heating error of only 0.021°C. Since the LM26LV's
junction temperature is the actual temperature being mea-
sured, care should be taken to minimize the load current that
the VTEMP output is required to drive. If The OVERTEMP out-
put is used with a 100 k pull-up resistor, and this output is
asserted (low), then for this example the additional contribu-
tion is [(152° C/W)x(5V)2/100k] = 0.038°C for a total self-
heating error of 0.059°C. Figure 3 shows the thermal
resistance of the LM26LV.
1.5 kΩ
800 Ω
FIGURE 2. LM26LV with series resistor for capacitive
loading greater than 1100 pF.
4.3 VOLTAGE SHIFT
The LM26LV is very linear over temperature and supply volt-
age range. Due to the intrinsic behavior of an NMOS/PMOS
rail-to-rail buffer, a slight shift in the output can occur when
the supply voltage is ramped over the operating range of the
device. The location of the shift is determined by the relative
levels of VDD and VTEMP. The shift typically occurs when
VDD − VTEMP = 1.0V.
NS Package
Number
Thermal
Device Number
Resistance (θJA
)
This slight shift (a few millivolts) takes place over a wide
change (approximately 200 mV) in VDD or VTEMP. Since the
shift takes place over a wide temperature change of 5°C to
20°C, VTEMP is always monotonic. The accuracy specifica-
tions in the Electrical Characteristics table already includes
this possible shift.
LM26LVCISD
SDB06A
152° C/W
FIGURE 3. LM26LV Thermal Resistance
5.0 Mounting and Temperature
Conductivity
The LM26LV can be applied easily in the same way as other
integrated-circuit temperature sensors. It can be glued or ce-
mented to a surface.
www.national.com
16
6.0 Applications Circuits
20204761
FIGURE 4. Temperature Switch Using Push-Pull Output
20204762
FIGURE 5. Temperature Switch Using Open-Drain Output
20204728
Most CMOS ADCs found in microcontrollers and ASICs have a sampled data comparator input structure. When the ADC charges
the sampling cap, it requires instantaneous charge from the output of the analog source such as the LM26LV temperature sensor
and many op amps. This requirement is easily accommodated by the addition of a capacitor (CFILTER). The size of CFILTER depends
on the size of the sampling capacitor and the sampling frequency. Since not all ADCs have identical input stages, the charge
requirements will vary. This general ADC application is shown as an example only.
FIGURE 6. Suggested Connection to a Sampling Analog-to-Digital Converter Input Stage
17
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20204718
FIGURE 7. Celsius Temperature Switch
20204760
FIGURE 8. TRIP TEST Digital Output Test Circuit
20204765
The TRIP TEST pin, normally used to check the operation of the OVERTEMP and OVERTEMP pins, may be used to latch the
outputs whenever the temperature exceeds the programmed limit and causes the digital outputs to assert. As shown in the figure,
when OVERTEMP goes high the TRIP TEST input is also pulled high and causes OVERTEMP output to latch high and the
OVERTEMP output to latch low. Momentarily switching the TRIP TEST input low will reset the LM26LV to normal operation. The
resistor limits the current out of the OVERTEMP output pin.
FIGURE 9. Latch Circuit using OVERTEMP Output
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18
Physical Dimensions inches (millimeters) unless otherwise noted
6-Lead LLP-6 Package
Order Number LM26LVCISD, LM26LVCISDX
NS Package Number SDB06A
19
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