LMT70, LMT70A ±0.05°C Precision Analog Temperature Sensor, RTD and Precision NTC Thermistor IC

1 Features

Accuracy:
- ±0.05°C (typ) or ±0.13°C (max) from 20°C to 42°C
- ±0.2°C (max) from -20°C to 90°C
- ±0.23°C (max) from 90°C to 110°C
- ±0.36°C (max) from -55°C to 150°C
Wide Temperature Range: −55°C to 150°C
Matching of Two Adjacent LMT70A on Tape and Reel: 0.1°C (max) at 30°C
Very Linear Analog Temperature Sensor with Output Enable Pin
NTC Output Slope: -5.19 mV/°C
Output On/Off Switch with R_{DS on} < 80 Ω
Wide Power Supply Range: 2.0 V to 5.5 V
Low Power Supply Current: 9.2 µA (typ)12 µA (max)
Ultra Small 0.88 mm by 0.88 mm 4-bump WLCSP (DSBGA) Package

2 Applications

Internet of Things (IoT) Sensor Nodes
Industrial RTD (Class AA) or Precision NTC/PTC Thermistor Replacement
Medical/Fitness Equipment
Medical Thermometer
Human Body temperature monitor
Metering Temperature Compensation

3 Description

The LMT70 is an ultra-small, high-precision, low-power CMOS analog temperature sensor with an output enable pin. Applications for the LMT70 include virtually any type of temperature sensing where cost-effective, high precision and low-power are required, such as Internet of Things (IoT) sensor nodes, medical thermometers, high-precision instrumentation and battery powered devices. The LMT70 is also a great replacement for RTD and precision NTC/PTC thermistors.

Its output enable pin allows multiple LMT70s to share one ADC channel, thus simplifying ADC calibration and reducing the overall system cost for precision temperature sensing. The LMT70 also has a linear and low impedance output allowing seamless interface to an off-the-shelf MCU/ADC. Dissipating less than 36µW, the LMT70 has ultra-low self-heating supporting its high-precision over a wide temperature range.

The LMT70A provides unparalleled temperature matching performance of 0.1°C (max) for two adjacent LMT70A's picked from the same tape and reel. Therefore, the LMT70A is an ideal solution for energy metering applications requiring heat transfer calculations.

Device Information⁽¹⁾

PART NUMBER	PACKAGE	BODY SIZE (NOM)
LMT70	DSBGA - WLCSP (4) YFQ	0.88 mm x 0.88 mm

(1) For all available packages, see the orderable addendum at the end of the data sheet.

4 Wide-Range Precision Active RTD or NTC Replacement (−55°C to 150°C)

4.0.0.1 LMT70 Accuracy vs Temperature

5 Revision History

Changes from * Revision (March 2015) to A Revision

Added typical accuracy specification.Go
Expanded range for ±0.2°C accuracy from "20°C to 90°C" to "-20°C to 90°C".Go
Added 9.2µA (typ). Go
Updated schematicGo
Added -20°C accuracy specification Go
Changed from 20°C to 20°C to 42°C for accuracy specification condition Go
Added 50°C accuracy specification Go
Added typical supply current specification.Go
Changed from 942.547 to 942.552Go
Changed from 943.907 to 943.902Go
Changed from 890.423 to 890.500Go
Changed from 891.934 to 891.857Go
Added -20°C histogram curveGo
Removed erroneous 10°C histogramGo
Changed y axis units from (V) to (mV)Go
Added Output Noise vs Frequency curveGo

6 Device Comparison Table

Order Number	Matching Specification Provided⁽¹⁾
LMT70YFQR, LMT70YFQT	No
LMT70AYFQR, LMT70AYFQT	Yes, 0.1°C at approximately 30°C⁽¹⁾

(1) In order to meet the matching specification of the LMT70A, two units must be picked from adjacent positions from one tape and reel. If PCB rework is required, involving the LMT70A, then the pair of the LMT70A matched units must be replaced. Matching features (which include, without limitation, electrical matching characteristics of adjacent Components as they are delivered in original packaging from TI) are warranted solely to the extent that the purchaser can demonstrate to TI’s satisfaction that the particular Component(s) at issue were adjacent in original packaging as delivered by TI. Customers should be advised that the small size of these Components means they are not individually traceable at the unit level and it may be difficult to establish the original position of the Components once they have been removed from that original packaging as delivered by TI.

7 Pin Configuration and Functions

DSBGA or WLCSP

4 Pins YFQ

(Top View)

Pin Functions

PIN		TYPE	EQUIVALENT CIRCUIT	DESCRIPTION
NAME	NO.	TYPE	EQUIVALENT CIRCUIT	DESCRIPTION
GND	A1	Ground		Ground reference for the device
VDD	A2	Power		Supply voltage
TAO	B1	Analog Output		Temperature analog output pin
T_ON	B2	Digital Input		T_ON pin. Active High input. If T_ON = 0, then the TAO output is open. If T_ON = 1, then TAO pin is connected to the temperature output voltage. Tie this pin to VDD if not used.