Texas Instruments LM26CIM5-ZHA/NOPB

Overview

LM26CIM5-ZHA/NOPB from Texas Instruments is a factory-preset, ±3°C accurate digital-output thermostat with fixed 120°C overtemperature shutdown trip point, open-drain active-low OS output, and programmable 2°C/10°C hysteresis via HYST pin. It integrates temperature sensor, reference, DAC, and comparator in a 5-pin SOT-23 package and supports microprocessor thermal shutdown and fan control applications.

For engineers reviewing the LM26CIM5-ZHA/NOPB datasheet, LM26CIM5-ZHA/NOPB pinout, LM26CIM5-ZHA/NOPB application, or LM26CIM5-ZHA/NOPB equivalent, key selection criteria include trip point accuracy (±3°C), hysteresis configuration (GND/V+), VTEMP analog output slope (−10.82 mV/°C), supply current (16 µA typical), and open-drain output compatibility with CMOS logic levels.

Technical Context

The LM26CIM5-ZHA/NOPB implements a precision analog temperature sensing path feeding an internal comparator with factory-trimmed reference and DAC, enabling deterministic 120°C trip activation. Its VTEMP pin outputs a nonlinear voltage defined by VO = (−3.479 × 10⁻⁶ × (T − 30)²) + (−1.082 × 10⁻² × (T − 30)) + 1.8015 V, supporting post-assembly verification and system-level temperature monitoring.

Hysteresis is implemented digitally via HYST pin state: GND selects 11°C typical hysteresis (10°C nominal), V+ selects 2°C typical hysteresis. The open-drain OS output requires ≥10 kΩ pullup resistor and sinks up to 1.2 mA while maintaining <0.4 V low-level voltage at 25°C.

Key Specifications

Pinout & Package

LM26CIM5-ZHA/NOPB is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, with thermal pad connected to GND (pin 2) for enhanced thermal coupling to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar thermostat applications.

Compared with LM26CIM5-VHA/NOPB and LM26CIM5-XHA/NOPB, the LM26CIM5-ZHA/NOPB provides the highest factory-set trip point in the LM26 family, making it uniquely suited for high-temperature industrial environments where extended thermal headroom is mandatory before shutdown.

Availability

LM26CIM5-ZHA/NOPB is available at Aetrix Electronics and suitable for microprocessor thermal management, fan control, industrial process control, and electronic system protection requiring stable component supply across long-lifecycle industrial programs.

Supply support for LM26CIM5-ZHA/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 company delivering analog and embedded processing solutions, with leadership in precision analog ICs and industrial-grade temperature sensors.

The LM26 product line delivers factory-programmed thermostats optimized for reliable, zero-calibration thermal protection in space-constrained applications - designed specifically for embedded thermal shutdown where accuracy, low power, and integration are critical.

FAQ

What is the exact trip temperature of LM26CIM5-ZHA/NOPB and how is it programmed?

The LM26CIM5-ZHA/NOPB has a fixed factory-programmed overtemperature trip point of 120°C. This value is laser-trimmed during manufacturing and cannot be adjusted externally. The 'ZHA' suffix in the part number explicitly denotes the 120°C setting per TI's LM26 device comparison table, and the trip point remains stable across the full −55°C to +125°C operating range with ±3°C accuracy.

Does LM26CIM5-ZHA/NOPB support both overtemperature and undertemperature shutdown modes?

No. The LM26CIM5-ZHA/NOPB is configured exclusively for overtemperature shutdown (OS) with active-low open-drain output. Its factory programming fixes the function to OS - not US - and the output type to open-drain. Other variants like LM26CIM5-HHD support undertemperature or push-pull outputs, but LM26CIM5-ZHA/NOPB does not.

How do I configure hysteresis on LM26CIM5-ZHA/NOPB and what are the actual values?

Hysteresis on LM26CIM5-ZHA/NOPB is set by the HYST pin: connect to GND for ~11°C typical hysteresis (10°C nominal), or to V+ for ~2°C typical hysteresis. These values are measured and specified in the Electrical Characteristics table (Section 7.5). No external components are needed - the internal comparator adjusts its threshold dynamically after trip activation.

Can LM26CIM5-ZHA/NOPB be used for precise temperature measurement via the VTEMP pin?

Yes, the VTEMP pin provides a calibrated analog voltage proportional to temperature, defined by VO = (−3.479 × 10⁻⁶ × (T − 30)²) + (−1.082 × 10⁻² × (T − 30)) + 1.8015 V. With a high-impedance ADC, LM26CIM5-ZHA/NOPB supports ±3°C temperature readback accuracy from −30°C to +120°C, enabling system-level diagnostics and calibration verification.

What is the maximum allowable load on the OS output of LM26CIM5-ZHA/NOPB?

The OS output of LM26CIM5-ZHA/NOPB is rated to sink ≥1.2 mA while maintaining ≤0.4 V at 25°C. For reliable operation, use a pullup resistor ≥10 kΩ to the host logic rail. Driving heavier loads increases self-heating, which may shift the effective trip point; the datasheet specifies that 3.2 mA sink causes ~0.32°C junction temperature rise due to 1.28 mW dissipation.