Analog Devices Inc. LM334S8#TRPBF

Overview

LM334S8#TRPBF from Analog Devices (formerly Linear Technology) is a 3-terminal adjustable current source and linear temperature sensor in an 8-lead SOIC package, operating from 0.8V to 30V with 1µA–10mA set-current range, 0.02%/V regulation, and ±3°C accuracy when configured as a temperature sensor. It serves as a precision bias element in micropower analog stages and remote Kelvin-scaled temperature sensing circuits.

For engineers reviewing the LM334S8#TRPBF datasheet, LM334S8#TRPBF pinout, LM334S8#TRPBF application, or LM334S8#TRPBF equivalent, key selection criteria include its absolute-temperature-proportional output (0.336%/°C), low-voltage operation down to 0.8V, absence of reverse current, and compatibility with standard transistor-style bias networks for shunt references and cold-junction compensation.

Technical Context

The LM334S8#TRPBF implements a two-terminal current source architecture using an internal 67.7mV reference voltage proportional to absolute temperature (°K), enabling direct Kelvin-scale current output (e.g., 298µA at 25°C = 1µA/°K). Its core circuit uses matched transistors Q1/Q2 in a 17:1 ratio to enforce I_V− = I_SET/18, where I_SET = 67.7mV/R_SET.

It operates without external power supply connections beyond V+ and V−, draws no reverse current, and maintains regulation across 0.8V–30V terminal voltage. Thermal self-heating effects are significant above 100µA, requiring layout-aware thermal management-especially critical in high-accuracy temperature sensing where junction temperature rise directly impacts slope fidelity.

Key Specifications

Pinout & Package

LM334S8#TRPBF is housed in an 8-lead plastic SOIC (S8) package with 0.150-inch narrow body, JEDEC MS-012 compliant, and rated for 0°C to +70°C operating temperature.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current source and temperature sensor applications.

Compared with LM334Z#TR, LM334S8#TRPBF offers superior thermal performance and surface-mount compatibility; compared with LT3092IMS8E#PBF, it delivers simpler two-terminal operation and lower minimum voltage at the expense of current range and programmability.

Availability

LM334S8#TRPBF is available at Aetrix Electronics and suitable for remote temperature sensing, precision reference biasing, cold-junction compensation, and micropower analog stage design requiring stable component supply across industrial, test & measurement, and embedded sensor applications.

Supply support for LM334S8#TRPBF 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

Analog Devices acquired Linear Technology in 2017 and continues to manufacture and support its precision analog portfolio, including current sources, references, and sensor interface ICs.

The LM334 series was designed specifically for applications demanding high-accuracy, low-power, two-terminal current regulation and absolute-temperature-proportional sensing-targeting instrumentation, industrial monitoring, and battery-operated measurement systems.

FAQ

What is the minimum operating voltage for LM334S8#TRPBF at 10µA set current?

The LM334S8#TRPBF requires a minimum V+–V− voltage of 0.8V when set current is ≤100µA. At 10µA, this threshold holds true-verified in Electrical Characteristics table on page 3 of the LM134 Series datasheet. Below 0.8V, regulation degrades rapidly and the device may cease current regulation entirely. This makes LM334S8#TRPBF suitable for single-cell battery systems where headroom is constrained.

Can LM334S8#TRPBF be used as a zero-TC current source, and how?

Yes, LM334S8#TRPBF can be configured as a zero-temperature-coefficient current source by adding an external diode and resistor network that cancels its inherent 0.336%/°C slope. The method is documented in Figure TA02 and described on page 7 of the LM134 Series datasheet. This technique leverages the diode's negative TC to offset the LM334S8#TRPBF's positive TC, achieving <0.02%/°C net drift-ideal for stable biasing in precision amplifiers.

What is the maximum safe operating voltage across V+ and V− for LM334S8#TRPBF?

The absolute maximum V+–V− voltage for LM334S8#TRPBF is 30V, as specified in the Absolute Maximum Ratings table on page 2 of the LM134 Series datasheet. Exceeding this risks permanent damage. For reliable long-term operation, design margins should limit continuous operation to ≤25V, especially at elevated ambient temperatures where power dissipation increases junction temperature.

How does LM334S8#TRPBF differ from LM134 and LM234 variants?

LM334S8#TRPBF is rated for 0°C to +70°C operation and packaged in SOIC (S8); LM134 operates from –55°C to +125°C (obsolete), and LM234-3/-6 offer ±3°C or ±6°C temperature accuracy over –25°C to +100°C. All share identical core circuitry and electrical behavior, but LM334S8#TRPBF targets commercial-grade applications where cost, size, and reflow compatibility outweigh extended temperature range.

Is LM334S8#TRPBF pin-compatible with other packages in the LM334 family?

No-LM334S8#TRPBF uses an 8-pin SOIC (S8) footprint with only three functional pins (V+, V−, R) and five NC pins, whereas LM334Z#TR uses a 3-pin TO-92 and LM334H#TR uses a 3-pin TO-46 metal can. Pin mapping differs entirely across packages; PCB layout must be redesigned when switching between S8, Z, or H variants-even though electrical function remains identical.