STMicroelectronics STLM75DS2F

Overview

STLM75DS2F from STMicroelectronics is a digital temperature sensor IC with integrated sigma-delta ADC and I²C/SMBus interface, functioning as a thermal watchdog in system-level thermal management. It delivers ±0.5°C typical accuracy from –55°C to +125°C, operates from 2.7 V to 5.5 V, draws 125 µA typical supply current, and features an open-drain OS/INT pin configurable as comparator or interrupt output - deployed in PC motherboard thermal monitoring, power supply modules, and industrial controllers.

For engineers reviewing the STLM75DS2F datasheet, STLM75DS2F pinout, STLM75DS2F application, or STLM75DS2F equivalent, this page provides verified technical context, validated pin functions, confirmed thermal alarm behavior, real-world use cases, and documented alternatives for drop-in replacement or design migration scenarios.

Technical Context

The STLM75DS2F implements a bandgap-based temperature sensing element paired with a 9-bit sigma-delta ADC, producing a 16-bit two's complement digital output where bits 15–7 represent temperature resolution of 0.5°C. Its I²C interface supports up to 400 kHz clock rate and uses three address pins (A0–A2) to configure one of eight slave addresses per bus.

Thermal alert logic operates in two modes: comparator mode (OS latches low until temperature falls below THYS) and interrupt mode (OS requires register read or shutdown to clear). Fault tolerance (FT1/FT0 bits) enables configurable 1–4 consecutive over-limit samples before OS activation, mitigating noise-induced false triggers in electrically noisy environments.

Key Specifications

Pinout & Package

STLM75DS2F is packaged in MSOP8 (TSSOP8), a 3 mm × 3 mm, 0.65 mm pitch, 8-lead thin shrink small outline package suitable for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM75BIMM/NOPB, STLM75DS2F adds fault tolerance and extended accuracy range; versus MAX31820, it retains I²C compatibility and hardware interrupt capability - making it optimal for systems requiring deterministic, low-latency thermal response without host polling.

Availability

STLM75DS2F is available at Aetrix Electronics and suitable for PC motherboard thermal monitoring, industrial power supply modules, and network equipment fan control requiring stable component supply across multi-year production cycles.

Supply support for STLM75DS2F 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, mixed-signal, and power management ICs for industrial, automotive, and consumer markets.

The STLM75 belongs to ST's precision analog sensor product line, engineered specifically for embedded thermal management applications requiring autonomous hardware alerting, I²C interoperability, and robust operation across extended industrial temperature ranges.

FAQ

What is the default state of the OS/INT pin at power-up?

At power-up, the OS/INT pin defaults to active-low comparator mode with polarity bit (POL) = 0. It asserts low when measured temperature exceeds the TOS register value and remains low until temperature drops below THYS. No I²C initialization is required for basic thermostat operation - enabling immediate standalone functionality.

Does STLM75DS2F require external passive components for basic operation?

Yes - external 4.7 kΩ to 10 kΩ pull-up resistors on SDA, SCL, and OS/INT are mandatory due to their open-drain configuration. A 0.1 µF ceramic bypass capacitor on VDD is also recommended for supply noise suppression. No external RC network, trimming resistor, or calibration circuit is needed for specified accuracy.

How does fault tolerance (FT) affect OS/INT assertion timing?

Fault tolerance is controlled by FT1/FT0 bits in the Configuration Register and defines how many consecutive over-limit conversions (1, 2, 4, or 6) must occur before OS/INT activates. This prevents spurious alerts from transient noise or measurement glitches - especially critical in motor drive or switching power supply environments with high dv/dt interference.

Can STLM75DS2F operate reliably at 2.7 V supply voltage?

Yes - STLM75DS2F is fully specified from 2.7 V to 5.5 V. At 2.7 V, conversion time remains ≤150 ms, accuracy holds at ±2°C (–25°C to +100°C), and I²C communication complies with standard-mode timing. The 125 µA typical supply current is maintained, making it suitable for battery-powered or energy-harvesting thermal monitors.