TMP36 — Low Voltage Precision Centigrade Temperature Sensor

Overview

The TMP36 is a low-voltage, precision centigrade temperature sensor manufactured by Analog Devices. It provides a linear voltage output proportional to Celsius temperature at $10\text{ mV/}^\circ\text{C}$ .

Designed specifically for single-supply 2.7 V to 5.5 V operation (ideal for 3.3V microcontrollers like ESP32 or Raspberry Pi), it incorporates a 500 mV DC offset at $0^\circ\text{C}$ . This offset allows the sensor to measure negative temperatures down to $-40^\circ\text{C}$ without requiring a negative supply voltage rail.

Quick reference


Operating voltage (`VCC`)	2.7 V to 5.5 V DC
Output scale factor	$10.0\text{ mV / }^\circ\text{C}$ ( $100\text{ mV}$ at $-40^\circ\text{C}$ , $500\text{ mV}$ at $0^\circ\text{C}$ , $750\text{ mV}$ at $+25^\circ\text{C}$ )
Temperature range	$-40^\circ\text{C}$ to $+125^\circ\text{C}$
Accuracy	$\pm 1.0\text{ }^\circ\text{C}$ typical at $+25^\circ\text{C}$ ( $\pm 2.0\text{ }^\circ\text{C}$ max over range)
Quiescent current	50 µA typical
Shutdown current	0.5 µA max
Package options	TO-92 (3-pin plastic), SOIC-8, SOT-23

Pinout

Standard TO-92 Plastic Package (Flat side facing you, pins down)

text

        ┌─────────┐
        │  TMP36  │
        └─────────┘
          │  │  │
          1  2  3

Pin	Name	Type	Description
1	`VCC`	Power	Supply voltage (+2.7 V to +5.5 V DC)
2	`VOUT`	Analog Output	Voltage output ( $500\text{ mV}$ offset + $10\text{ mV/}^\circ\text{C}$ )
3	`GND`	Power	Ground (0 V)

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Supply Voltage	$V_{S}$	2.7	3.3 / 5.0	5.5	V	DC
Output Voltage at $0^\circ\text{C}$	$V_{0\text{C}}$	490	500	510	mV	$T_A = 0^\circ\text{C}$
Output Scale Factor	$S$	9.8	10.0	10.2	mV/°C	$+25^\circ\text{C}$
Accuracy	$\Delta T$	-2.0	$\pm 1.0$	+2.0	°C	Full $-40^\circ\text{C} \text{ to } +125^\circ\text{C}$ range
Quiescent Current	$I_{SY}$	—	50	65	µA	$V_{S} = 3.3\text{ V}$
Load Capacitance Drive	$C_{L}$	—	—	1000	pF	Without series resistor

Temperature Conversion Formula

To calculate temperature ( $T$ in °C) from the measured output voltage ( $V_{OUT}$ in Volts):

$T\text{ }(^\circ\text{C}) = \frac{V_{OUT}\text{ (in Volts)} - 0.500\text{ V}}{0.010\text{ V/}^\circ\text{C}} = (V_{OUT}\text{ (in mV)} - 500) \times 0.1$

With a 10-bit ADC ( $1024$ steps) on a $3.3\text{ V}$ microcontroller ( $V_{REF} = 3300\text{ mV}$ ):

$V_{OUT}\text{ (in mV)} = \frac{\text{ADC Reading} \times 3300\text{ mV}}{1024}$

$T\text{ }(^\circ\text{C}) = \frac{V_{OUT}\text{ (in mV)} - 500}{10}$

Wiring

TMP36 Pin	→	Microcontroller (Arduino Uno / ESP32)
1 (`VCC`)		`3.3V` (or `5V`)
2 (`VOUT`)		Analog Input Pin `A0` (or ESP32 ADC)
3 (`GND`)		`GND`

Common mistakes

Mixing up LM35 and TMP36 math: The LM35 outputs $0\text{ mV}$ at $0^\circ\text{C}$ , whereas the TMP36 outputs $500\text{ mV}$ at $0^\circ\text{C}$ . Forgetting to subtract 500 mV yields temperatures $50^\circ\text{C}$ too high!
Connecting pins backwards: Swapping VCC and GND causes the package to heat up rapidly and break.
Noisy ADC readings from long wires: High capacitive loads ( $>1000\text{ pF}$ ) can cause $V_{OUT}$ oscillation. Add a $1\text{ k}\Omega$ series resistor near $V_{OUT}$ or a $0.1\text{ }\mu\text{F}$ bypass capacitor between $V_{CC}$ and $GND$ .

Notes

The TMP36 is pin-compatible with the LM35 but operates at lower supply voltages ( $2.7\text{ V}$ min vs $4.0\text{ V}$ min).