TI LMT85DCKT Sc70/to-92, analog temperature sensors with class-ab output Datasheet

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LMT85, LMT85-Q1
SNIS168C – MARCH 2013 – REVISED OCTOBER 2015
LMT85/LMT85-Q1 SC70/TO-92, Analog Temperature Sensors with Class-AB Output
1 Features
3 Description
•
The LMT85/LMT85-Q1 are precision CMOS
integrated-circuit temperature sensors with an analog
output voltage that is linearly and inversely
proportional to temperature. Its features make it
suitable for many general temperature sensing
applications. It can operate down to 1.8V supply with
5.4 µA power consumption making it ideal for battery
powered devices. Package options including throughhole TO-92 package allows the LMT85 to be
mounted on-board, off-board, to a heat sink, or on
multiple unique locations in the same application. A
class-AB output structure gives the LMT85/LMT85Q1 strong output source and sink current capability
that can directly drive up to 1.1 nF capacitive loads.
This means it is well suited to drive an analog-todigital converter sample-and-hold input with its
transient load requirements. It has accuracy specified
in the operating range of −50°C to 150°C. The
accuracy, 3-lead package options, and other features
also make the LMT85/LMT85-Q1 an alternative to
thermistors.
1
•
•
•
•
•
•
•
•
•
LMT85-Q1 is AEC-Q100 Grade 0 qualified and is
manufactured on an automotive grade flow
Very accurate: ±0.4°C typical
Wide temperature range of -50°C to 150°C
Low 5.4µA quiescent current
Sensor gain of -8.2 mV/°C
Packages:
– Small SC70 (SOT 5-lead) surface mount
– Leaded TO-92
Output is short-circuit protected
Push-pull output with 50 µA source current
capability
Footprint compatible with the industry-standard
LM20/19 and LM35 temperature sensor
Cost-effective alternative to thermistors
2 Applications
•
•
•
•
•
•
•
•
Automotive
Industrial
White Goods – Appliances
Battery Management
Disk Drives
Games
Wireless Transceivers
Cell phones
For devices with different average sensor gains and
comparable
accuracy
the
LMT84/LM84-Q1,
LMT86/LMT86-Q1 and LMT87/LMT87-Q1 (For more
details see Comparable Alternative Devices.)
Device Information (1)
PART NUMBER
LMT85
LMT85-Q1
(1)
PACKAGE
BODY SIZE (NOM)
SOT (5)
2.00 mm x 1.25 mm
TO-92 (3)
4.3 mm x 3.5 mm
SOT (5)
2.00 mm x 1.25 mm
For all available packages, see the orderable addendum at
the end of the data sheet.
4 Full-Range Celsius Temperature Sensor (−50°C to 150°C)
VDD (+1.8V to +5.5V)
Output Voltage vs Temperature
VDD
LMT85
CBP
OUT
GND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LMT85, LMT85-Q1
SNIS168C – MARCH 2013 – REVISED OCTOBER 2015
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Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Full-Range Celsius Temperature Sensor (−50°C
to 150°C) .................................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
5
5
5
5
6
6
6
7
Absolute Maximum Ratings .....................................
ESD Ratings - Commercial .......................................
ESD Ratings - Automotive ........................................
Recommended Operating Ratings ...........................
Thermal Information ..................................................
Accuracy Characteristics...........................................
Electrical Characteristics ..........................................
Typical Characteristics .............................................
8.2 Functional Block Diagram ......................................... 9
8.3 Feature Description................................................... 9
8.4 Device Functional Modes........................................ 11
9
1
2
4
5
Detailed Description .............................................. 9
8.1 Overview ................................................................... 9
Application and Implementation ........................ 13
9.1 Application Information............................................ 13
9.2 Typical Applications ................................................ 13
10 Power Supply Recommendations ..................... 15
11 Layout................................................................... 15
11.1 Layout Guidelines ................................................. 15
11.2 Layout Example .................................................... 15
12 Device and Documentation Support ................. 17
12.1
12.2
12.3
12.4
12.5
Related Links ........................................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
17
17
17
17
17
13 Mechanical, Packaging, and Orderable
Information ........................................................... 17
5 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision B (May 2014) to Revision C
Page
•
Deleted TO-126 package throughout data sheet ................................................................................................................... 1
•
Added TO-92 LPM pin configuration graphic ......................................................................................................................... 4
•
Changed Handling Ratings to ESD Ratings and moved Storage Temperature to Absolute Maximum Ratings table........... 5
•
Changed KV to V ................................................................................................................................................................... 5
•
Added TO-92 LP and LPM layout recommendations........................................................................................................... 15
Changes from Revision A (June 2013) to Revision B
Page
•
Changed data sheet flow and layout to conform with new TI standards. Added the following sections: Application
and Implementation, Power Supply Recommendations, Layout, Device and Documentation Support, Mechanical,
Packaging, and Orderable Information .................................................................................................................................. 1
•
Added TO-92 and TO-126 package information throughout document ................................................................................. 1
•
Deleted 450 °C/W to 275 °C/W. New specification is derived using TI ' s latest methodology. ........................................... 6
•
Changed Temperature Accuracy Conditions from 70°C to 20°C and VDD from 1.9V to 1.8V................................................ 6
•
Deleted Note: The input current is leakage only and is highest at high temperature. It is typically only 0.001 µA. The
1 µA limit is solely based on a testing limitation and does not reflect the actual performance of the part............................. 6
2
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Device Comparison Table (1)
ORDER NUMBER
PACKAGE
(2)
BODY SIZE (NOM)
Mounting Type
LMT85DCK
SOT (AKA
5
2.00 mm x 1.25 mm
Surface Mount
LMT85LP
TO-92 (AKA (2): LP)
3
4.3 mm x 3.5 mm
Through-hole; straight leads
LMT85LPM
TO-92 (AKA (2): LPM)
3
4.3 mm x 3.5 mm
Through-hole; formed leads
5
2.00 mm x 1.25 mm
Surface Mount
LMT85DCK-Q1
(1)
(2)
SOT (AKA
: SC70, DCK)
PIN
(2)
: SC70, DCK)
For all available packages and complete order numbers, see the orderable addendum at the end of the data sheet.
AKA = Also Known As
Comparable Alternative Devices
PART NUMBER
AVERAGE OUTPUT SENSOR GAIN
POWER SUPPLY RANGE
LMT84/LMT84-Q1
–5.5 mV/°C
1.5V to 5.5V
LMT85/LMT85-Q1
–8.2 mV/°C
1.8V to 5.5V
LMT86/LMT86-Q1
–10.9 mV/°C
2.2V to 5.5V
LMT87/LMT87-Q1
–13.6 mV/°C
2.7V to 5.5V
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6 Pin Configuration and Functions
5-Pin SOT/SC70
DCK Package
(Top View)
1
3-Pin TO-92
LPM Package
5
GND
VDD
2
LMT85
GND
3
4
OUT
VDD
3-Pin TO-92
LP Package
VDD
OUT
GND
VDD
OUT
GND
Pin Functions
PIN
LABEL
DCK
NUMBER
DESCRIPTION
LP
NUMBER
LPC
NUMBER
TYPE
GND
5
Ground
VDD
1
Power
EQUIVALENT CIRCUIT
FUNCTION
Power Supply Ground
Positive Supply Voltage
VDD
OUT
Analog
Output
3
See Pin
Diagrams
Outputs a voltage which is inversely
proportional to temperature
See Pin
Diagrams
GND
VDD
4
Power
Positive Supply Voltage
GND
2
Ground
Power Supply Ground, (direct
connection to the back side of the
die)
4
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7 Specifications
7.1 Absolute Maximum Ratings
(1) (2)
MIN
MAX
Unit
Supply Voltage
−0.3
6
V
Voltage at Output Pin
−0.3
(VDD + 0.5)
V
-7
7
mA
Output Current
Input Current at any pin
(3)
-5
Maximum Junction Temperature (TJMAX)
Storage temperature Tstg
(1)
(2)
(3)
-65
5
mA
150
°C
150
°C
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 specific performance limits. For specifications and test conditions, see the Electrical
Characteristics. The specifications apply only for the test conditions listed. Some performance characteristics may degrade when the
device is not operated under the listed test conditions.
Soldering process must comply with Texas Instruments Reflow Temperature Profile specifications. Refer to www.ti.com/packaging..
Reflow temperature profiles are different for lead-free and non-lead-free packages.
When the input voltage (VI) at any pin exceeds power supplies (VI < GND or VI > V), the current at that pin should be limited to 5 mA.
7.2 ESD Ratings - Commercial
VALUE
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins.
Applies for TO-92 package LMT85LP.
VESD
(1)
(2)
(3)
Electrostatic discharge
UNIT
(1)
±2500
Human Bode Mod (HBM), per JESD22-A114, all pins. Applies for SC70
package LMT85DCK.
±2500
Charged device model (CDM), per JEDEC specification JESD22-C101,
all pins. (2) Applies for all parts.
±1000
Machine model ESD stress voltage, per JEDEC specification JESD22A115. (3) Applies for SC70 package LMT85DCK.
±250
V
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
The machine model is a 200pF capacitor discharged directly into each pin.
7.3 ESD Ratings - Automotive
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per JESD22-A114, all
pins. (1) Applies for SC70 package LMT85DCK-Q1.
±2500
Charged-device model (CDM), per JEDEC
specification JESD22-C101, all pins. (2) Applies for
SC70 package LMT85DCK-Q1.
±1000
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.4 Recommended Operating Ratings
MIN
Specified temperature
VDD
Supply voltage
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MAX
TMIN ≤ TA ≤ TMAX
°C
−50 ≤ TA ≤ +150
1.8
UNIT
5.5
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°C
V
5
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7.5 Thermal Information (1)
THERMAL METRIC
(2)
LMT85/
LMT85-Q1
LMT85
DCK
LP
5 PIN
3 PIN
275
167
(3) (4)
RθJA
Junction-to-ambient thermal resistance
RθJC(top)
Junction-to-case (top) thermal resistance
84
90
RθJB
Junction-to-board thermal resistance
56
146
ψJT
Junction-to-top characterization parameter
1.2
35
ψJB
Junction-to-board characterization parameter
55
146
(1)
(2)
(3)
(4)
UNIT
°C/W
For information on self-heating and thermal response time see section Mounting and Thermal Conductivity.
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
The junction to ambient thermal resistance, RθJA, is specified without a heat sink in still air.
Changes in output due to self heating can be computed by multiplying the internal dissipation by the thermal resistance.
7.6 Accuracy Characteristics
These limits do not include DC load regulation. These stated accuracy limits are with reference to the values in Table 1.
PARAMETER
(3)
Temperature accuracy
MIN (1)
TEST CONDITIONS
TYP (2) MAX
UNIT
TA = TJ= 20°C to 150°C; VDD = 1.8 V to 5.5 V
-2.7
±0.4
2.7
°C
TA = TJ= 0°C to 150°C; VDD = 1.9 V to 5.5 V
-2.7
±0.7
2.7
°C
TA = TJ= 0°C to 150°C; VDD = 2.6 V to 5.5 V
±0.3
TA = TJ= –50°C to 0°C; VDD = 2.3 V to 5.5 V
-2.7
°C
±0.7
TA = TJ= –50°C to 0°C; VDD = 2.9 V to 5.5 V
(1)
(2)
(3)
(1)
2.7
±0.25
°C
°C
Limits are specific to TI's AOQL (Average Outgoing Quality Level).
Typicals are at TJ = TA = 25°C and represent most likely parametric norm.
Accuracy is defined as the error between the measured and reference output voltages, tabulated in the Transfer 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.
7.7 Electrical Characteristics
Unless otherwise noted, these specifications apply for VDD = +1.8V to +5.5V. MIN and MAX limits apply for TA = TJ = TMIN to
TMAX, unless otherwise noted; typical values apply for TA = TJ = 25°C.
PARAMETER
Average sensor gain (output
transfer function slope)
Load regulation
Line regulation
IS
CL
6
(1)
-30°C and 90°C used to calculate average sensor gain
Source ≤ 50 μA, (VDD - VOUT) ≥ 200 mV
–1
Sink ≤ 50 μA, VOUT ≥ 200 mV
(2)
MAX
(1)
TA = TJ = -50°C to 150°C, (VDD - VOUT) ≥ 100 mV
mV/°C
–0.22
mV
1
TA = TJ = 25°C
5.4
8.1
μA
5.4
9
μA
1.9
ms
+50
µA
0.7
–50
mV
μV/V
1100
CL= 0 pF to 1100 pF
UNIT
–8.2
200
TA = TJ = 30°C to 150°C, (VDD - VOUT) ≥ 100 mV
(5)
TYP
0.26
Output load capacitance
Output drive
(5)
MIN
(4)
Supply current
Power-on time
(1)
(2)
(3)
(4)
(3)
TEST CONDITIONS
pF
Limits are specific to TI's AOQL (Average Outgoing Quality Level).
Typicals are at TJ = TA = 25°C and represent most likely parametric norm.
Source currents are flowing out of the LMT85/LMT85-Q1. Sink currents are flowing into the LMT85/LMT85-Q1.
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 Output Voltage Shift.
Specified by design and characterization.
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7.8 Typical Characteristics
4
Minimum Operating Temperature (ƒC)
40
TEMPERATURE ERROR (ºC)
3
2
1
0
-1
-2
-3
-4
-50
-25
0
25
50
75
100 125 150
30
20
10
0
±10
±20
±30
±40
±50
1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50
Supply Voltage (V)
TEMPERATURE (ºC)
C002
Figure 1. Temperature Error vs Temperature
Figure 2. Minimum Operating Temperature vs
Supply Voltage
Figure 3. Supply Current vs Temperature
Figure 4. Supply Current vs Supply Voltage
Figure 5. Load Regulation, Sourcing Current
Figure 6. Load Regulation, Sinking Current
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Typical Characteristics (continued)
Figure 7. Change in Vout vs Overhead Voltage
Figure 8. Supply-Noise Gain vs Frequency
Figure 9. Output Voltage vs Supply Voltage
8
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8 Detailed Description
8.1 Overview
The LMT85/LMT85-Q1 is an analog output temperature sensor. The temperature sensing element is comprised
of a simple base emitter junction that is forward biased by a current source. The temperature sensing element is
then buffered by an amplifier and provided to the OUT pin. The amplifier has a simple push-pull output stage
thus providing a low impedance output source.
8.2 Functional Block Diagram
Full-Range Celsius Temperature Sensor (−50°C to 150°C).
VDD
OUT
Thermal Diodes
GND
8.3 Feature Description
8.3.1 LMT85/LMT85-Q1 Transfer Function
The output voltage of the LMT85/LMT85-Q1, across the complete operating temperature range, is shown in
Table 1. This table is the reference from which the LMT85/LMT85-Q1 accuracy specifications (listed in the
Accuracy Characteristics section) are determined. This table can be used, for example, in a host processor lookup table. A file containing this data is available for download at LMT85 product folder under Tools and Software
Models.
Table 1. LMT85/LMT85-Q1 Transfer Table
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
-50
1955
-10
1648
30
1324
70
991
110
651
-49
1949
-9
1639
31
1316
71
983
111
642
-48
1942
-8
1631
32
1308
72
974
112
634
-47
1935
-7
1623
33
1299
73
966
113
625
-46
1928
-6
1615
34
1291
74
957
114
617
-45
1921
-5
1607
35
1283
75
949
115
608
-44
1915
-4
1599
36
1275
76
941
116
599
-43
1908
-3
1591
37
1267
77
932
117
591
-42
1900
-2
1583
38
1258
78
924
118
582
-41
1892
-1
1575
39
1250
79
915
119
573
-40
1885
0
1567
40
1242
80
907
120
565
-39
1877
1
1559
41
1234
81
898
121
556
-38
1869
2
1551
42
1225
82
890
122
547
-37
1861
3
1543
43
1217
83
881
123
539
-36
1853
4
1535
44
1209
84
873
124
530
-35
1845
5
1527
45
1201
85
865
125
521
-34
1838
6
1519
46
1192
86
856
126
513
-33
1830
7
1511
47
1184
87
848
127
504
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Feature Description (continued)
Table 1. LMT85/LMT85-Q1 Transfer Table (continued)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
TEMP
(°C)
VOUT
(mV)
-32
1822
8
1502
48
1176
88
839
128
495
-31
1814
9
1494
49
1167
89
831
129
487
-30
1806
10
1486
50
1159
90
822
130
478
-29
1798
11
1478
51
1151
91
814
131
469
-28
1790
12
1470
52
1143
92
805
132
460
-27
1783
13
1462
53
1134
93
797
133
452
-26
1775
14
1454
54
1126
94
788
134
443
-25
1767
15
1446
55
1118
95
779
135
434
-24
1759
16
1438
56
1109
96
771
136
425
-23
1751
17
1430
57
1101
97
762
137
416
-22
1743
18
1421
58
1093
98
754
138
408
-21
1735
19
1413
59
1084
99
745
139
399
-20
1727
20
1405
60
1076
100
737
140
390
-19
1719
21
1397
61
1067
101
728
141
381
-18
1711
22
1389
62
1059
102
720
142
372
-17
1703
23
1381
63
1051
103
711
143
363
-16
1695
24
1373
64
1042
104
702
144
354
-15
1687
25
1365
65
1034
105
694
145
346
-14
1679
26
1356
66
1025
106
685
146
337
-13
1671
27
1348
67
1017
107
677
147
328
-12
1663
28
1340
68
1008
108
668
148
319
-11
1656
29
1332
69
1000
109
660
149
310
150
301
Although the LMT85/LMT85-Q1 is very linear, its response does have a slight umbrella parabolic shape. This
shape is very accurately reflected in Table 1. The Transfer Table can be calculated by using the parabolic
equation.
mV
mV
ª
º ª
2º
VTEMP mV = 1324.0mV - «8.194
T - 30°C » - «0.00262 2 T - 30°C »
°C
¬
¼ ¬
°C
¼
(1)
The parabolic equation is an approximation of the transfer table and the accuracy of the equation degrades
slightly at the temperature range extremes. Equation 1 can be solved for T resulting in:
T
8 . 194
8 . 194
2
4 u 0 . 00262 u 1324
2 u 0 . 00262
VTEMP mV
30
(2)
For an even less accurate linear transfer function approximation, a line can easily be calculated over the desired
temperature range using values from the Table and a two-point equation:
·
¹
V - V1 =
V2 - V1
T2 - T1
· u (T - T1)
¹
(3)
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 resolve this equation, over a temperature range of 20°C to 50°C, we would proceed
as follows:
1159 mV - 1405 mV·
u (T - 20oC)
50oC - 20oC
¹
·
¹
V - 1405 mV =
o
10
(4)
o
V - 1405 mV = (-8.20 mV / C) u (T - 20 C)
(5)
o
V = (-8.20 mV / C) u T + 1569 mV
(6)
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Using this method of linear approximation, the transfer function can be approximated for one or more
temperature ranges of interest.
8.4 Device Functional Modes
8.4.1 Mounting and Thermal Conductivity
The LMT85/LMT85-Q1 can be applied easily in the same way as other integrated-circuit temperature sensors. It
can be glued or cemented to a surface.
To ensure good thermal conductivity, the backside of the LMT85/LMT85-Q1 die is directly attached to the GND
pin (Pin 2 for the SOT/SC70/DCK package). The temperatures of the lands and traces to the other leads of the
LMT85/LMT85-Q1 will also affect the temperature reading.
Alternatively, the LMT85/LMT85-Q1 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 LMT85/LMT85-Q1 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 condensation can occur. If moisture creates a short circuit from
the output to ground or VDD, the output from the LMT85/LMT85-Q1 will not be correct. Printed-circuit coatings are
often used to ensure that moisture cannot corrode the leads or circuit traces.
The thermal resistance junction to ambient (RθJA or θJA) parameter used to calculate the rise of a device junction
temperature due to its power dissipation. The equation used to calculate the rise in the LMT85/LMT85-Q1 die
temperature is:
TJ = TA + TJA ª¬(VDDIS ) + (VDD - VOUT ) IL º¼
(7)
where TA is the ambient temperature, IS is the supply current, ILis the load current on the output, and VO is the
output voltage. For example, in an application where TA = 30°C, VDD = 5 V, IS = 5.4 μA, VOUT = 1324 mV, and
IL = 2 μA, the junction temperature would be 30.014°C, showing a self-heating error of only 0.014°C. Since the
LMT85/LMT85-Q1's junction temperature is the actual temperature being measured, care should be taken to
minimize the load current that the LMT85/LMT85-Q1 is required to drive. For the thermal resistance of the
LMT85/LMT85Q1 in different packages see sectionThermal Information (1).
8.4.2 Output and Noise Considerations
A push-pull output gives the LMT85/LMT85-Q1 the ability to sink and source significant current. This is beneficial
when, for example, 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. The LMT85/LMT85Q1 are ideal for this and other applications which require strong source or sink current.
The LMT85/LMT85-Q1's supply-noise gain (the ratio of the AC signal on VOUT to the AC signal on VDD) was
measured during bench tests. Its typical attenuation is shown in Figure 8 found in the Typical Characteristics
section. A load capacitor on the output can help to filter noise.
For operation in very noisy environments, some bypass capacitance should be present on the supply within
approximately 5 centimeters of the LMT85/LMT85-Q1.
8.4.3 Capacitive Loads
The LMT85/LMT85-Q1 handles capacitive loading well. In an extremely noisy environment, or when driving a
switched sampling input on an ADC, it may be necessary to add some filtering to minimize noise coupling.
Without any precautions, the LMT85/LMT85-Q1 can drive a capacitive load less than or equal to 1100 pF as
shown in Figure 10. For capacitive loads greater than 1100 pF, a series resistor may be required on the output,
as shown in Figure 11.
(1)
For information on self-heating and thermal response time see section Mounting and Thermal Conductivity.
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Device Functional Modes (continued)
VDD
LMT85
OPTIONAL
BYPASS
CAPACITANCE
OUT
GND
CLOAD ” 1100 pF
Figure 10. LMT85 No Decoupling Required for Capacitive Loads Less Than 1100 pF
VDD
RS
LMT85
OPTIONAL
BYPASS
CAPACITANCE
OUT
GND
CLOAD > 1100 pF
Figure 11. LMT85 with Series Resistor for Capacitive Loading Greater Than 1100 pF
CLOAD
Minimum RS
1.1 nF to 99 nF
3 kΩ
100 nF to 999 nF
1.5 kΩ
1 μF
800 Ω
8.4.4 Output Voltage Shift
The LMT85/LMT85-Q1 are very linear over temperature and supply voltage 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
VOUT. The shift typically occurs when VDD- VOUT = 1 V.
This slight shift (a few millivolts) takes place over a wide change (approximately 200 mV) in VDD or VOUT. Since
the shift takes place over a wide temperature change of 5°C to 20°C, VOUT is always monotonic. The accuracy
specifications in the Accuracy Characteristics table already include this possible shift.
12
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9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
The LMT85/LMT85-Q1 features make it suitable for many general temperature sensing applications. It can
operate down to 1.8V supply with 5.4 uA power consumption making it ideal for battery powered devices.
Package options including through-hole TO-92 package allows the LMT85 to be mounted on-board, off-board, to
a heat sink, or on multiple unique locations in the same application.
9.2 Typical Applications
9.2.1 Connection to an ADC
Simplified Input Circuit of
SAR Analog-to-Digital Converter
Reset
+1.8V to +5.5V
Input
Pin
LMT85
VDD
CBP
RMUX
RSS
Sample
OUT
GND
CFILTER
CMUX
CSAMPLE
Figure 12. Suggested Connection to a Sampling Analog-to-digital Converter Input Stage
9.2.1.1 Design Requirements
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 LMT85/LMT85-Q1 temperature sensor and many op amps. This requirement is easily accommodated by
the addition of a capacitor (CFILTER). This general ADC application is shown as an example only.
9.2.1.2 Detailed Design Procedure
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.
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Typical Applications (continued)
9.2.1.3 Application Curves
Figure 13. Analog Output Transfer Function
9.2.2 Conserving Power Dissipation with Shutdown
VDD
SHUTDOWN
VOUT
LMT85
Any logic
device output
Figure 14. Simple Shutdown Connection of the LMT85
9.2.2.1 Design Requirements
Since the power consumption of the LMT85 is less than 9 µA it can simply be powered directly from any logic
gate output, thus not requiring a specific shutdown pin. The device can even be powered directly from a micro
controller GPIO. In this way it can easily be turned off for cases such as battery powered systems where power
savings is critical.
9.2.2.2 Detailed Design Procedure
Simply connect the VDD pin of the LMT85 directly to the logic shutdown signal from a microcontroller.
9.2.2.3 Application Curves
Time: 500 µsec/div; Top Trace: VDD 1 V/div;
Bottom Trace: OUT 1 V/div
Figure 15. Output Turn-on Response Time without a
Capacitive Load and VDD= 3.3V
14
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Time: 500 µsec/div; Top trace: VDD 2 V/div;
Bottom trace: OUT 1 V/div
Figure 16. Output Turn-on Response Time without a
Capacitive Load and VDD= 5V
Copyright © 2013–2015, Texas Instruments Incorporated
LMT85, LMT85-Q1
www.ti.com
SNIS168C – MARCH 2013 – REVISED OCTOBER 2015
Typical Applications (continued)
Time: 500 µsec/div; Top trace: VDD 1V/div;
Bottom trace: OUT 1 V/div
Figure 17. Output Turn-on Response Time with 1.1 nF
Capacitive Load and VDD= 3.3V
Time: 500 µsec/div; Top trace: VDD 2 V/div;
Bottom trace: OUT 1 V/div
Figure 18. Output Turn-on Response Time with 1.1 nF
Capacitive Load and VDD= 5V
10 Power Supply Recommendations
The LMT85's low supply current and supply range of 1.8V to 5.5V allow the device to easily be powered from
many sources.
Power supply bypassing is optional and is mainly dependent on the noise on the power supply used. In noisy
systems it may be necessary to add bypass capacitors to lower the noise that is coupled to the LMT85's output.
11 Layout
11.1 Layout Guidelines
The LMT85 is extremely simple to layout. If a power supply bypass capacitor is used it should be connected as
shown in the Layout Example.
11.2 Layout Example
VIA to ground plane
VIA to power plane
VDD
GND
GND
OUT
0.01µ F
VDD
Figure 19. SC70 Package Recommended Layout
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Layout Example (continued)
GND
OUT
VDD
Figure 20. TO-92 LP Package Recommended Layout
GND
OUT
VDD
Figure 21. TO-92 LPM Package Recommended Layout
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SNIS168C – MARCH 2013 – REVISED OCTOBER 2015
12 Device and Documentation Support
12.1 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.
Table 2. Related Links
PARTS
PRODUCT FOLDER
SAMPLE & BUY
TECHNICAL
DOCUMENTS
TOOLS &
SOFTWARE
SUPPORT &
COMMUNITY
LMT85
Click here
Click here
Click here
Click here
Click here
LMT85-Q1
Click here
Click here
Click here
Click here
Click here
12.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
12.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
12.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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PACKAGE OPTION ADDENDUM
www.ti.com
13-Aug-2015
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Op Temp (°C)
Device Marking
(4/5)
LMT85DCKR
ACTIVE
SC70
DCK
5
3000
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-50 to 150
BPA
LMT85DCKT
ACTIVE
SC70
DCK
5
250
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-50 to 150
BPA
LMT85LP
ACTIVE
TO-92
LP
3
1800
Green (RoHS
& no Sb/Br)
CU SN
N / A for Pkg Type
-50 to 150
LMT85
LMT85LPM
ACTIVE
TO-92
LP
3
2000
Green (RoHS
& no Sb/Br)
CU SN
N / A for Pkg Type
-50 to 150
LMT85
LMT85QDCKRQ1
ACTIVE
SC70
DCK
5
3000
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-50 to 150
BRA
LMT85QDCKTQ1
ACTIVE
SC70
DCK
5
250
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-50 to 150
BRA
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
13-Aug-2015
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
OTHER QUALIFIED VERSIONS OF LMT85, LMT85-Q1 :
• Catalog: LMT85
• Automotive: LMT85-Q1
NOTE: Qualified Version Definitions:
• Catalog - TI's standard catalog product
• Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
13-Aug-2015
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
LMT85DCKR
SC70
DCK
5
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
3000
178.0
8.4
2.25
2.45
1.2
4.0
8.0
Q3
LMT85DCKT
SC70
DCK
5
250
178.0
8.4
2.25
2.45
1.2
4.0
8.0
Q3
LMT85QDCKRQ1
SC70
DCK
5
3000
178.0
8.4
2.25
2.45
1.2
4.0
8.0
Q3
LMT85QDCKTQ1
SC70
DCK
5
250
178.0
8.4
2.25
2.45
1.2
4.0
8.0
Q3
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
13-Aug-2015
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
LMT85DCKR
SC70
DCK
5
3000
210.0
185.0
35.0
LMT85DCKT
SC70
DCK
5
250
210.0
185.0
35.0
LMT85QDCKRQ1
SC70
DCK
5
3000
210.0
185.0
35.0
LMT85QDCKTQ1
SC70
DCK
5
250
210.0
185.0
35.0
Pack Materials-Page 2
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