STMicroelectronics LM335Z

Overview

LM335Z from STMicroelectronics is a precision 2-terminal Zener-based temperature sensor calibrated in Kelvin, delivering 10 mV/°K linear output with ±1°C initial accuracy over –40°C to +100°C. It operates from 450 µA to 5 mA, exhibits <0.6 Ω dynamic impedance, and is housed in a TO-92 plastic package for direct mounting in ambient or thermally coupled environments such as HVAC sensor nodes and industrial process monitors.

For engineers reviewing the LM335Z datasheet, LM335Z pinout, LM335Z application, or LM335Z equivalent, key selection criteria include its absolute-temperature linearity, low self-heating error at 1 mA bias, calibration flexibility via single-point slope adjustment, and compatibility with simple op-amp conditioning circuits in analog front-end designs.

Technical Context

The LM335Z functions as a programmable Zener diode whose breakdown voltage tracks absolute temperature at 10 mV/°K - e.g., 2.982 V at 25°C (298.15 K). Its two-terminal architecture eliminates need for excitation current sourcing or reference voltage generation.

It achieves <1°C calibrated error across –40°C to +100°C when adjusted at 25°C, with non-linearity ≤1.5°C and thermal time constant of 80 s in still air. Dynamic impedance remains below 0.6 Ω at 1 mA, enabling stable operation without external buffering in high-impedance measurement paths.

Key Specifications

Pinout & Package

LM335Z uses a TO-92 plastic package (bulk packing), with three leads arranged in bottom-view orientation: Pin 1 = Adjust (ADJ), Pin 2 = Positive Terminal (V+), Pin 3 = Negative Terminal (V–).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision analog temperature sensing applications.

Compared with LM335AZ, the LM335Z trades factory accuracy for lower cost and identical analog interface simplicity; versus TSIC 306-100, it retains full analog design control and avoids digital bus dependencies but requires external signal conditioning.

Availability

LM335Z is available at Aetrix Electronics and suitable for industrial process monitoring, HVAC ambient sensing, differential temperature measurement, and thermocouple cold-junction compensation requiring stable component supply and long-lifecycle support.

Supply support for LM335Z 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, power, and microcontroller solutions for industrial, automotive, and consumer markets.

The LM335Z belongs to ST's precision analog sensor family, engineered specifically for cost-effective, high-stability temperature measurement in commercial and light-industrial equipment where linearity, low power, and ease of calibration are essential.

FAQ

What is the correct bias current for optimal accuracy?

LM335Z achieves best linearity and lowest self-heating error at 1 mA bias current. At this level, dynamic impedance is minimized (0.5–0.6 Ω), and temperature coefficient deviation is <0.3°C over –40°C to +100°C. Operating below 450 µA increases noise susceptibility; above 5 mA risks excessive self-heating beyond datasheet limits.

How do I perform single-point calibration?

Apply a known reference temperature (e.g., 25°C in a stirred oil bath), measure output voltage (e.g., 2.982 V), then adjust the ADJ pin using a 10 kΩ potentiometer in series with a 10 kΩ resistor to scale output to exactly 10 mV/°K. This corrects slope error across the full range without requiring multi-point characterization.

Can LM335Z be used in battery-powered devices?

Yes - LM335Z draws as little as 450 µA, enabling >5-year operation on a standard CR2032 coin cell when sampled intermittently. Its wide current range allows pairing with low-quiescent-current LDOs or resistor-biased supplies, and its 10 mV/°K output yields ~200 mV full-scale swing over 20°C–40°C ambient ranges, compatible with 10-bit ADCs.

Is LM335Z RoHS-compliant and lead-free?

Yes - LM335Z is supplied in STMicroelectronics' ECOPACK®-compliant TO-92 package with lead-free second-level interconnect, meeting JEDEC JESD97 standards. The inner box label and package marking indicate lead-free status, and all maximum soldering ratings are documented per JEDEC J-STD-020.