LM35Analog temperature sensor

Temperature in. A voltage you can read out.

Manufacturer-referenced

Texas Instruments · LM35DZ

TO-92SNIS159H · December 2017

LM35 produces an analog voltage proportional to Celsius temperature. This page selects the LM35DZ in a three-lead TO-92 package. Its rated range is 0°C to 100°C; other family grades have different limits. Choose LM35DZ in TO-92 or LM35DM in SOIC-8. Both are LM35D grades; the SOIC package has five unused leads and different physical pin numbers.

Real View

LM35DZ package rendered from the same geometry as the interactive 3D model, with silver leads.

Pinout

LM35DZTO-92Bottom view · flat edge below

PCB Footprint

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3D View

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Supply & groundTemperature outputNo connection

LM35DZTO-92Bottom view · flat edge below

Click a lead or use the arrow keys. Bottom view · flat edge below

PIN 1 · Supply & ground

+VS

Power

Function

Positive supply input.

How to connect

Connect to a regulated 4–30 V supply. A 5 V rail suits the Arduino example.

At a glance

Analog temperature sensor

No serial protocol or register setup is needed. Measure VOUT relative to GND.

4–30 VSupply

10 mV/°COutput scale

0–100 °CLM35D range

3 pinsConnections

Operating profile

LM35DZ

At 25°C: 250 mVCalculated from the nominal scale.
Selected grade: LM35DZTO-92 · LM35D commercial grade.
Readout: Analog ADCVoltage measurement, no I2C address.

Operating conditions

Key parameters and their test conditions

Supply: 4–30 VConditions / notes: Recommended operating supply
LM35DZ temperature: 0–100°CConditions / notes: LM35D grade; not the full LM35 family range
Scale: 10 mV/°CConditions / notes: Nominal linear conversion
Accuracy at 25°C: ±1.5°C maximumConditions / notes: LM35D; use the grade-specific table

Package details

Follows the selected physical package

Manufacturer: Texas Instruments
Part number: LM35DZ
Package: TO-92
Connections: 3 pins
Mounting: Through-hole
Lead pitch: See LP package drawing
Package code: LP
Thermal reference: See manufacturer thermal table

Connections by function

Select a pin to open its function, electrical notes and wiring guidance.

Supply & ground2 pins

Temperature output1 pins

LM35 temperature sensor: interactive pinout, TO-92 package, analog transfer equation and an Arduino thermometer example. — Open the image for a closer look. The individual diagrams are also available in their own tabs.

Power and bypass

Connect +VS to a regulated 5 V supply and GND to the common return. Place the illustrated 10 nF supply bypass close to the sensor.

Measure the output

Connect VOUT to a high-impedance ADC or voltmeter. At 25°C, expect about 250 mV. Keep wiring short; use TI’s isolation network for a heavy capacitive load.

Interpret the reading

Multiply volts by 100 to obtain °C. For a 10-bit ADC, use the reference voltage and 1024 quantization levels. The selected LM35D grade is specified from 0 to 100°C; the simple single-supply circuit has limitations near zero.

Temperature (°C) = measured output (V) × 100. ADC reference accuracy also affects the result.

LM35 functional architecture: bias and reference, temperature sensing, trimmed analog gain and low-impedance output buffer. — Color follows the signal path. This is a functional explanation, not a transistor-level die schematic.

LM35DZ TO-92 sensor with numbered silver leads, a 10 nF supply capacitor, colorful wiring and a microcontroller ADC displaying an illustrative temperature. — Physical package orientation and lead numbers are explicit. All matching supply labels and ground symbols refer to the same nets; readings are illustrative.

Pin reference

Select a pin to explore its function and connection.

3 pins

Signal	Type	Function
+VS	Power	Positive supply input.
VOUT	Analog output	Temperature output: 10 mV per °C.
GND	Ground	Supply and measurement reference.
NC	Not connected	SOIC physical lead 2 has no internal connection.
NC	Not connected	SOIC physical lead 3 has no internal connection.
NC	Not connected	SOIC physical lead 5 has no internal connection.
NC	Not connected	SOIC physical lead 6 has no internal connection.
NC	Not connected	SOIC physical lead 7 has no internal connection.

Operating conditions

Reviewed manufacturer specifications

Manufacturer specifications 4 parameters

Parameter	Value	Conditions / notes
Supply	4–30 V	Recommended operating supply
LM35DZ temperature	0–100°C	LM35D grade; not the full LM35 family range
Scale	10 mV/°C	Nominal linear conversion
Accuracy at 25°C	±1.5°C maximum	LM35D; use the grade-specific table

Do not apply another LM35 grade’s accuracy or range to LM35DZ.

Voltage to temperature

Reviewed manufacturer specifications

Manufacturer specifications 4 parameters

Temperature	VOUT	Interpretation
0°C	0 mV	Nominal equation; near-zero single-supply output has limits
25°C	250 mV	Nominal
50°C	500 mV	Nominal
100°C	1.000 V	Nominal

ADC conversion

Reviewed manufacturer specifications

Manufacturer specifications 3 parameters

Parameter	Value	Conditions / notes
Formula	T = ADC × VREF / (2^N − 1) × 100	Endpoint-scaled ideal ADC estimate
10-bit / 5 V	≈0.489°C per count	Calculated resolution; not sensor accuracy
Reference	Use measured VREF	Supply variation creates conversion error

Arduino LCD thermometer

Use the linked example to inspect the sensor output and the firmware’s temperature conversion.

Manufacturer application guide

Temperature monitoring

Measure ambient or surface temperature within the selected grade’s range. Choose mounting and response time for the measurement.

Manufacturer application guide

Take it into ProTech

Find LM35 in the Components Library to place its schematic symbol and connect its pins.

Simulation model available · Open the working exampleOpen ProTech