NXP Semiconductors LM75ADP,118

Overview

LM75ADP,118 from NXP Semiconductors is a digital temperature sensor and thermal watchdog IC featuring an on-chip bandgap sensor, 11-bit sigma-delta ADC, I²C-bus interface, open-drain OS output, and programmable overtemperature shutdown (80 °C default) and hysteresis (75 °C default). It operates from −55 °C to +125 °C with ±2 °C accuracy (−25 °C to +100 °C) and 0.125 °C resolution, used in system thermal management for PCs, industrial controllers, and embedded electronics.

For engineers reviewing the LM75ADP,118 datasheet, LM75ADP,118 pinout, LM75ADP,118 application, or LM75ADP,118 equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative parts - all grounded in NXP's official LM75A product data sheet Rev. 04 (2007).

Technical Context

The LM75ADP,118 implements a bandgap-based temperature sensing core with 11-bit sigma-delta A/D conversion, delivering 0.125 °C resolution via a 2's complement 11-bit Temp register. Its thermal watchdog logic compares measured temperature against user-programmable Tos and Thyst registers (9-bit, 0.5 °C resolution) to drive the open-drain OS output in either comparator or interrupt mode.

Configuration is managed through an 8-bit Conf register controlling shutdown mode (3.5 µA), OS polarity (active LOW/HIGH), OS operation mode (comparator/interrupt), and fault queue (1–6 consecutive faults). The device supports up to eight units on one I²C bus via three hardware address pins (A2–A0), with default power-up settings: normal mode, OS comparator, Tos = 80 °C, Thyst = 75 °C, OS active LOW.

Key Specifications

Pinout & Package

TSSOP8 package (SOT505-1), 3 mm body width, 0.65 mm pitch, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital temperature sensor applications.

Compared with STLM75DT and MAX31826ATM+, the LM75ADP,118 offers guaranteed I²C compatibility with legacy LM75 designs, lowest system integration effort due to identical register map and default behavior, and optimal balance of resolution, accuracy, and power for cost-sensitive thermal guard applications.

Availability

LM75ADP,118 is available at Aetrix Electronics and suitable for server thermal monitoring, industrial PLC temperature guard, and embedded edge gateway applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LM75ADP,118 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets, with deep expertise in mixed-signal sensor ICs and embedded interfaces.

The LM75A family was designed specifically for reliable, low-cost thermal monitoring in space-constrained embedded systems - emphasizing I²C simplicity, self-contained watchdog operation, and wide industrial temperature tolerance.

FAQ

What is the default power-up configuration of the LM75ADP,118?

At power-up, the LM75ADP,118 initializes in normal operation mode with OS comparator mode enabled, Tos set to 80 °C, Thyst to 75 °C, OS active LOW, fault queue = 1, and pointer register = 0 selecting the Temp register. This allows immediate temperature reading without configuration, making LM75ADP,118 usable as a plug-and-play thermal watchdog.

How does the OS output behave in comparator versus interrupt mode on the LM75ADP,118?

In comparator mode, the OS output activates when temperature exceeds Tos and deactivates only when it falls below Thyst - independent of register reads or shutdown commands. In interrupt mode, OS activates on Tos crossing and remains asserted until any register is read. Both modes are controlled by bit B1 in the LM75ADP,118 Configuration register and retain their state across power cycles.

Can the LM75ADP,118 measure temperature accurately while in shutdown mode?

No - in shutdown mode, the LM75ADP,118 halts analog-to-digital conversion; the Temp register retains its last valid value but no new measurements occur. The I²C interface remains fully functional, allowing register access and configuration changes, but temperature updates require returning to normal mode. Shutdown draws only 3.5 µA, ideal for battery-backed thermal logging where updates are infrequent.

What is the significance of the 11-bit temperature data format in the LM75ADP,118?

The LM75ADP,118 stores temperature as an 11-bit 2's complement value in the Temp register, yielding 0.125 °C resolution over −55 °C to +125 °C. Only the 11 most significant bits of the two-byte read are valid; the five LSBs of the LSByte are zero and must be ignored. This format enables precise thermal drift analysis - a key advantage over legacy 9-bit sensors like the original LM75.

Is the LM75ADP,118 pin-compatible with the original LM75?

Yes - the LM75ADP,118 is a pin-for-pin replacement for the industry-standard LM75 in TSSOP8 package, maintaining identical pinout, I²C address structure, register map, and default power-up behavior. It improves upon the LM75 with enhanced 0.125 °C resolution and guaranteed specification across 2.8–5.5 V supply, making LM75ADP,118 a direct upgrade path without PCB changes.