LM75B Digital Temp Sensor

Name: LM75B Digital Temp Sensor
Brand: Texas Instruments
Availability: InStock

LM75B

Texas Instrumentssensor environment

The LM75B is a digital temperature sensor with an I2C interface, providing 9-bit accuracy over a wide temperature range.

Manufacturer datasheet

Buy · DigiKey Buy · Mouser Buy · Amazon

In stock

Specifications

Operating Voltage: 3 V to 5.5 V
Supply Current: 280 μA (typical) (shutdown: 4 μA)
Interface: I2C
Resolution: 9 bits
Range: -55°C to 125°C
Accuracy: ±3°C (−55°C to 125°C) (±2°C −25°C to 100°C)
Temperature Range: -55°C to 125°C
Package: SOIC (8), VSSOP (8)

Pinout

Pin	Name	Functions	Notes
1	SDA	I2C	I2C serial bi-directional data line
2	SCL	I2C	I2C clock input
3	O.S.	GPIO	Open drain output for over-temperature shutdown
4	GND	GND	Ground
5	A2	GPIO	User-set I2C address input (ground for low, +VS for high)
6	A1	GPIO	User-set I2C address input (ground for low, +VS for high)
7	A0	GPIO	User-set I2C address input (ground for low, +VS for high)
8	+VS	POWER	Positive supply voltage input

Interactive pinout

Highlight:

LM75B

Click a pin to copy its name · tap a tag above to spotlight a bus.

Starter code

Community starter examples — minimal, unofficial, and provided to get you wiring fast. Verify against the manufacturer datasheet before relying on them.

Arduino (C++)

arduino

// LM75B I2C temperature sensor — community starter example
// No library needed: read the 11-bit temperature register (0x00).
#include <Wire.h>

const byte ADDR = 0x48;   // A2..A0 -> GND

float readTempC() {
  Wire.beginTransmission(ADDR);
  Wire.write(0x00);
  Wire.endTransmission();
  Wire.requestFrom(ADDR, (byte)2);
  int raw = (Wire.read() << 8) | Wire.read();
  return (raw >> 5) * 0.125;        // 11-bit, 0.125 C/LSB
}

void setup() {
  Serial.begin(115200);
  Wire.begin();
}

void loop() {
  Serial.print(readTempC()); Serial.println(" C");
  delay(1000);
}

MicroPython

python

# LM75B (ESP32) — community starter example
from machine import Pin, I2C
import time

i2c = I2C(0, scl=Pin(22), sda=Pin(21))
ADDR = 0x48

while True:
    d = i2c.readfrom_mem(ADDR, 0x00, 2)
    raw = (d[0] << 8) | d[1]
    print((raw >> 5) * 0.125, "C")
    time.sleep(1)

Wiring

Pin	Arduino Uno R3	ESP32 DevKitC (WROOM-32)	Notes
VCC	+5V	3V3	2.8-5.5 V
GND	GND	GND
SCL	A5/SCL	GPIO22	I2C clock
SDA	A4/SDA	GPIO21	I2C data
A0/A1/A2	-	-	Address select -> 0x48-0x4F
O.S.	-	-	Over-temp interrupt output (optional)

Typical uses

Digital temperature with over-temp alarm
Thermal protection / fan control