Analog Devices Inc. LM334Z#TRPBF

Overview

LM334Z#TRPBF from Analog Devices (formerly Linear Technology) is a 3-terminal adjustable current source and linear temperature sensor in TO-92 plastic package, delivering 1µA–10mA set current with 0.02%/V regulation, 0.8V–40V operating voltage range, and ±3°C accuracy when used as a Kelvin-referenced temperature sensor at 100µA–1mA. It serves as a micropower bias network or cold-junction compensator in industrial sensor interfaces.

For engineers reviewing the LM334Z#TRPBF datasheet, LM334Z#TRPBF pinout, LM334Z#TRPBF application, or LM334Z#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 PCB footprints for embedded thermal monitoring and precision current sourcing.

Technical Context

The LM334Z#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 regulation relies on matched transistor pairs (Q1:Q2 = 17:1) to maintain I_SET = 67.7mV/R_SET, independent of supply voltage within specified limits.

Thermal self-heating effects are significant above 100µA - junction temperature rise ≈0.4°C per volt across the device at 1mA - requiring layout-aware heat sinking in DC-critical applications. The 15pF shunt capacitance at the R pin affects AC impedance and may be buffered via FET for high-frequency stability.

Key Specifications

Pinout & Package

Z Package: 3-lead plastic TO-92 (similar to TO-226), through-hole mount, 0.180" lead spacing, 0.016"–0.024" lead diameter (solder dip finish).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM334Z#TRPBF, LM334Z offers identical performance in bulk packaging but lacks tape-and-reel logistics support, while REF200AU trades programmability and temperature linearity for tighter fixed-current tolerance - making LM334Z#TRPBF uniquely suited for dual-role current source/temperature sensor designs requiring field calibration and wide dynamic range.

Availability

LM334Z#TRPBF is available at Aetrix Electronics and suitable for industrial temperature monitoring, shunt reference biasing, and micropower sensor interface applications requiring stable component supply across production lifecycles.

Supply support for LM334Z#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 maintains full product support, documentation, and manufacturing continuity for legacy Linear parts including the LM334 series.

The LM334Z#TRPBF belongs to Linear's precision current source and temperature sensor family, designed specifically for applications demanding Kelvin-proportional current output, micropower operation, and minimal external components in commercial-temperature environments.

FAQ

What is the minimum operating voltage for LM334Z#TRPBF?

The LM334Z#TRPBF has a minimum operating voltage of 0.8V at I_SET ≤ 100µA and 0.9V at 100µA < I_SET ≤ 1mA. This low-voltage capability enables use in energy-harvesting systems and single-cell battery applications. The LM334Z#TRPBF achieves regulation down to this threshold by leveraging its internal 67.7mV temperature-proportional reference and matched transistor architecture.

How does LM334Z#TRPBF function as a temperature sensor?

The LM334Z#TRPBF outputs current directly proportional to absolute temperature (I_SET ∝ T°K), with a nominal slope of 0.336%/°C - e.g., 298µA at 25°C yields 1µA/°K. As a two-wire current-mode sensor, it rejects lead resistance errors, making LM334Z#TRPBF ideal for remote industrial sensing. Calibration requires only one trim point due to inherent linearity.

Can LM334Z#TRPBF be used in reverse-biased configurations?

Yes - the LM334Z#TRPBF tolerates up to 20V reverse voltage (V− to V+) without damage or reverse current flow. This allows safe integration in floating-sensor bridges or bidirectional current paths. However, normal current-source operation requires forward bias (V+ > V−), and the LM334Z#TRPBF draws no reverse current, eliminating leakage concerns in multiplexed systems.

What is the role of the R pin on LM334Z#TRPBF?

The R pin on LM334Z#TRPBF is the reference control node, held internally at 67.7mV above V−. Connecting an external resistor R_SET between R and V− sets I_SET = 67.7mV/R_SET. This pin's 15pF shunt capacitance impacts high-frequency impedance, so FET buffering is recommended for AC-coupled or fast-transient applications involving the LM334Z#TRPBF.

Does LM334Z#TRPBF require external components for basic operation?

No - the LM334Z#TRPBF operates as a true two-terminal current source with only R_SET required to define I_SET. No external power supplies, op-amps, or feedback networks are needed. Its self-contained architecture means LM334Z#TRPBF delivers regulated current with just one resistor, reducing design complexity and board space in biasing and sensing functions.