Texas Instruments LM4040B50IDBZT

Overview

LM4040B50IDBZT from Texas Instruments is a precision micropower shunt voltage reference delivering a fixed 5.0V output with ±0.2% initial accuracy (B grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current - used in high-accuracy analog input modules and data-acquisition front-ends.

For engineers reviewing the LM4040B50IDBZT datasheet, LM4040B50IDBZT pinout, LM4040B50IDBZT application, or LM4040B50IDBZT equivalent, key selection criteria include industrial-temperature-grade (–40°C to 85°C) stability, SOT-23-3 package compatibility, low-noise performance for ADC biasing, and minimal external component requirements in space-constrained designs.

Technical Context

The LM4040B50IDBZT operates as a two-terminal shunt reference, sinking cathode current to maintain a precise 5.0V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves tight initial tolerance without external components, and its low dynamic impedance (≤0.8Ω at 1mA) ensures regulation stability under varying load currents.

It functions within a recommended cathode current range of 45μA–15mA and is characterized over –40°C to +85°C ambient temperature. The device exhibits thermal hysteresis of ≤0.08% and long-term stability of 120ppm after 1000 hours, making it suitable for calibration-critical instrumentation where drift must be minimized.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: compact 2.92mm × 1.30mm footprint with gull-wing leads, optimized for automated assembly and thermal dissipation in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt voltage reference applications.

Compared with REF3050AIDBZR and ADR3450ARJZ-R7, the LM4040B50IDBZT offers true 2-pin simplicity and zero-supply-headroom operation, making it optimal for loop-powered and ultra-low-voltage systems - though with higher tempco than the ADR3450 and shunt-specific layout constraints versus the REF3050's series topology.

Availability

LM4040B50IDBZT is available at Aetrix Electronics and suitable for data-acquisition systems, analog input modules, and field transmitters requiring stable component supply with guaranteed long-term sourcing and TI-authorized traceability.

Supply support for LM4040B50IDBZT 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 leader specializing in analog and embedded processing technologies, with decades of expertise in precision reference design and industrial-grade reliability validation.

The LM4040 family was engineered for cost-sensitive, space-constrained applications demanding high initial accuracy and low drift - particularly in sensor signal chains, portable instrumentation, and programmable logic controller (PLC) analog I/O subsystems.

FAQ

What is the maximum cathode current rating for LM4040B50IDBZT?

The absolute maximum cathode current for LM4040B50IDBZT is 25mA, per TI's Absolute Maximum Ratings. However, the recommended operating range is 45μA to 15mA to ensure specified accuracy, thermal stability, and long-term reliability. Exceeding 15mA may increase self-heating and degrade the 100ppm/°C temperature coefficient performance of the LM4040B50IDBZT.

Does LM4040B50IDBZT require an output capacitor for stability?

No, LM4040B50IDBZT is inherently stable with all capacitive loads and does not require an external output capacitor. Its design eliminates the need for stabilization components, reducing BOM count and PCB area - a key advantage confirmed in TI's datasheet Section 3 and Figure 8-1 typical application circuit for the LM4040B50IDBZT.

What is the thermal hysteresis specification for LM4040B50IDBZT?

The thermal hysteresis of LM4040B50IDBZT is specified at ≤0.08%, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to +125°C. This low hysteresis ensures repeatable reference voltage behavior in applications subject to repeated thermal cycling, such as outdoor energy meters and industrial controllers using the LM4040B50IDBZT.

Can LM4040B50IDBZT be used in automotive applications?

LM4040B50IDBZT is rated for –40°C to +85°C (industrial grade), not the full AEC-Q100 automotive temperature range (–40°C to +125°C). While it may function in under-hood or cabin environments with local thermal management, TI does not qualify or guarantee the LM4040B50IDBZT for automotive safety-critical systems. For such use, consider the LM4040C50Q or LM4040D50Q variants instead.

How does the NC pin (Pin 3) on LM4040B50IDBZT affect EMI performance?

Pin 3 of LM4040B50IDBZT is a no-connect terminal; TI recommends tying it to the anode (Pin 2) in high-EMI environments - such as near transformers or switching power supplies - to reduce noise coupling into the reference node. This practice is documented in the LM4040B50IDBZT datasheet Figure 5-1 and Section 5 Pin Functions, improving immunity without altering electrical functionality.