Texas Instruments LM75AIMM/NOPB

Overview

LM75AIMM/NOPB from Texas Instruments is a digital temperature sensor IC with integrated sigma-delta ADC and I²C interface, delivering 9-bit temperature readings with ±2°C accuracy from –25°C to 100°C and ±3°C over –55°C to 125°C. It operates from 2.7 V to 5.5 V, features programmable overtemperature shutdown (O.S.) with hysteresis and fault queue, and supports up to eight devices on one I²C bus - used in PC thermal monitoring, base station environmental control, and embedded system thermal watchdog applications.

For engineers reviewing the LM75AIMM/NOPB datasheet, LM75AIMM/NOPB pinout, LM75AIMM/NOPB application, or LM75AIMM/NOPB equivalent, key selection considerations include its 9-bit resolution, ±2°C accuracy range, open-drain O.S. output with programmable polarity and fault tolerance, I²C compatibility up to 400 kHz, and VSSOP-8 package footprint for space-constrained thermal sensing nodes.

Technical Context

The LM75AIMM/NOPB implements a silicon bandgap temperature sensor feeding a 9-bit sigma-delta ADC, with decimation filtering to produce stable digital output. Its internal register map includes read-only Temperature and Product ID registers, plus configurable TOS/THYST setpoint and Configuration registers controlling shutdown, comparator/interrupt mode, O.S. polarity, and fault queue depth (1–6 consecutive over-limit events).

It operates in two functional modes: Comparator mode (O.S. toggles between TOS and THYST thresholds) and Interrupt mode (O.S. remains asserted until cleared via I²C read). Power-up defaults include comparator mode, TOS = 80°C, THYST = 75°C, active-low O.S., and pointer register initialized to Temperature register - enabling immediate stand-alone thermostat operation without host intervention.

Key Specifications

Pinout & Package

VSSOP-8 package (3.00 mm × 3.00 mm), thermally enhanced for accurate die temperature measurement; pin-compatible with SOIC-8 variant but smaller footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STLM75CDT6 and MAX31820MUA+, the LM75AIMM/NOPB uniquely balances I²C simplicity, programmable fault resilience, and VSSOP-8 compactness - making it optimal for cost-sensitive, noise-prone embedded thermal watchdogs needing deterministic response without microcontroller overhead.

Availability

LM75AIMM/NOPB is available at Aetrix Electronics and suitable for PC thermal monitoring, telecom base station environmental control, and industrial PLC cabinet temperature supervision requiring stable component supply and long-term production continuity.

Supply support for LM75AIMM/NOPB 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in precision sensing and industrial-grade IC design.

The LM75AIMM/NOPB belongs to TI's precision analog temperature sensor product line, engineered specifically for reliable thermal management in computing, communications, and industrial equipment where robustness, ease of integration, and I²C compatibility are critical.

FAQ

What is the default power-up behavior of the LM75AIMM/NOPB?

At power-up, the LM75AIMM/NOPB initializes to comparator mode with TOS = 80°C, THYST = 75°C, O.S. active low, and pointer register pointing to the Temperature register. This allows immediate stand-alone thermostat operation without I²C configuration - ideal for fail-safe thermal protection in systems where host firmware may not initialize promptly.

Does the LM75AIMM/NOPB require external components for basic operation?

No external components are required for core functionality: the LM75AIMM/NOPB operates as a complete digital temperature sensor with integrated ADC and I²C interface. However, TI recommends a 100 nF bypass capacitor on +VS and 10 kΩ pullup resistors on SCL/SDA lines for noise immunity and reliable bus operation - especially in electrically noisy environments.

How does the fault queue feature improve reliability in the LM75AIMM/NOPB?

The LM75AIMM/NOPB's programmable fault queue (1–6 consecutive over-limit readings) prevents false O.S. assertions caused by transient noise or short thermal spikes. For example, setting D3–D4 = 11 configures six faults before activation - essential in motor drive or switching power supply applications where EMI could otherwise cause unnecessary system shutdowns.

Can the LM75AIMM/NOPB operate without an I²C host controller?

Yes - the LM75AIMM/NOPB supports fully autonomous operation using its default power-up configuration. With A0–A2 grounded or tied to +VS for address setting and O.S. connected to a fan driver or reset circuit, it functions as a hardware thermal watchdog independent of software, making it suitable for safety-critical or boot-time protection scenarios.

What is the maximum I²C bus speed supported by the LM75AIMM/NOPB?

The LM75AIMM/NOPB supports I²C Fast-mode operation up to 400 kHz, as verified in its digital switching characteristics table. This enables rapid polling intervals (e.g., sub-10 ms between reads) for time-sensitive thermal response loops, while maintaining compatibility with standard microcontroller I²C peripherals without custom timing adjustments.