LM75BDP

The LM75BDP from NXP Semiconductors is a temperature-to-digital converter using an on-chip bandgap temperature sensor and sigma-delta ADC with 11-bit resolution (0.125°C). The device provides an overtemperature shutdown (OS) output with programmable threshold and hysteresis, making it ideal as a thermal watchdog. The I2C/SMBus compatible interface supports up to 400kHz clock speed, and up to 8 devices can share the same bus via the A0-A2 address select pins. A shutdown mode reduces current consumption to 3.5μA for power-sensitive applications. Pin-for-pin compatible with the industry standard LM75 and LM75A.

The LM75BDP uses a bandgap temperature sensor whose output voltage is proportional to absolute temperature (PTAT). This analog voltage is digitized by an internal sigma-delta ADC to produce an 11-bit two’s complement temperature value. The temperature register is continuously updated at a default rate of one conversion every 100ms. The OS output compares the measured temperature against two programmable thresholds: Tos (overtemperature shutdown) and Thyst (hysteresis). When temperature exceeds Tos, the OS pin activates (active low, open-drain). The OS pin deactivates only when the temperature drops below Thyst, providing a stable thermostat behavior without oscillation.

• PC and server motherboard thermal monitoring and fan control
• Industrial equipment overtemperature alarm and protection
• Battery pack temperature monitoring in EV and UPS
• Hard disk drive thermal protection
• Multi-zone temperature sensing with up to 8 sensors on one bus