Texas Instruments LM4040A50IDBZT

Overview

LM4040A50IDBZT from Texas Instruments is a precision micropower shunt voltage reference with 5.0V nominal output, ±0.1% initial accuracy (A 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 systems.

For engineers reviewing the LM4040A50IDBZT datasheet, LM4040A50IDBZT pinout, LM4040A50IDBZT application, or LM4040A50IDBZT equivalent, this page delivers verified specifications, package mapping to SOT-23-3 (DBZ), thermal hysteresis (0.08%), long-term stability (120ppm), and real-world design implications for low-noise, low-current reference circuits.

Technical Context

The LM4040A50IDBZT operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 5.0V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon junction delivers tight initial tolerance and low dynamic impedance (0.8Ω typical at 1mA), enabling stable regulation without external capacitors even under varying load or supply conditions.

Designed for industrial ambient temperatures (–40°C to +85°C), it features fuse-trimmed voltage calibration and achieves 100ppm/°C max temperature coefficient over full range. Thermal hysteresis is specified at 0.08%, and long-term stability is 120ppm after 1000 hours at 25°C - critical for metrology-grade calibration and sensor front-end designs.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92mm × 1.30mm footprint, surface-mount, thermally efficient with RθJA = 206°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040A50IDBZT, REF3050AIDBZR offers lower noise and better tempco but demands external capacitance and higher operating current; ADR3450ARJZ-R7 provides superior long-term stability and noise performance but requires a dedicated supply rail - making LM4040A50IDBZT optimal for simple, low-cost, capacitor-free shunt configurations.

Availability

LM4040A50IDBZT is available at Aetrix Electronics and suitable for analog input modules, data-acquisition systems, and energy infrastructure applications requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for LM4040A50IDBZT 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 high-reliability manufacturing.

The LM4040 series was developed for cost-sensitive, space-constrained applications demanding high accuracy without external components - targeting industrial sensing, test equipment, and portable instrumentation markets.

FAQ

What is the maximum cathode current rating for LM4040A50IDBZT?

The absolute maximum cathode current for LM4040A50IDBZT is 25mA per TI's Absolute Maximum Ratings table. However, the recommended operating range is 45μA to 15mA. Exceeding 15mA may increase self-heating and degrade long-term stability or tempco performance. The device remains functional up to 25mA but should be derated per thermal calculations using RθJA = 206°C/W.

Does LM4040A50IDBZT require an output capacitor?

No, LM4040A50IDBZT is explicitly designed to operate stably with all capacitive loads and does not require an output capacitor. This is confirmed in the datasheet Features section and Simplified Schematic - eliminating BOM cost and PCB area while simplifying layout for space-constrained applications like handheld test gear.

What is the thermal hysteresis specification for LM4040A50IDBZT?

LM4040A50IDBZT has a thermal hysteresis of 0.08%, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to +125°C. This value is consistent across all LM4040 grades and packages, and is critical for applications involving repeated thermal cycling, such as field-deployed calibration standards.

Can LM4040A50IDBZT be used in automotive applications?

LM4040A50IDBZT is qualified for industrial temperature range (–40°C to +85°C), not the full AEC-Q100 automotive grade. While it may function in under-hood environments with local thermal management, TI does not certify it for automotive safety-critical systems. For automotive use, consider LM4040Q series (e.g., LM4040C50Q) rated to +125°C and qualified per AEC-Q100.

How does the 45μA minimum cathode current impact low-power design?

The 45μA typical minimum cathode current of LM4040A50IDBZT enables direct use in ultra-low-power systems such as battery-operated sensors and energy-harvesting nodes. It allows the reference to remain active while consuming less than many microcontrollers' sleep-mode current - preserving system battery life without sacrificing voltage accuracy or noise performance.