Texas Instruments LM4040C50IDBZTG4

Overview

LM4040C50IDBZTG4 from Texas Instruments is a precision micropower shunt voltage reference with 5.0V nominal output, ±0.5% initial accuracy (C 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 field transmitters requiring low-drift, low-noise biasing.

For engineers reviewing the LM4040C50IDBZTG4 datasheet, LM4040C50IDBZTG4 pinout, LM4040C50IDBZTG4 application, or LM4040C50IDBZTG4 equivalent, key selection criteria include guaranteed 5.0V output tolerance over –40°C to 85°C, SOT-23-3 package compatibility, cathode current headroom for sensor excitation, and absence of required output capacitance in space-constrained designs.

Technical Context

The LM4040C50IDBZTG4 operates as a two-terminal shunt reference, sinking cathode current (IZ) to regulate voltage across its terminals. Its Zener-based architecture uses wafer-level fuse/Zener-zap trimming to achieve 0.5% initial accuracy, with dynamic impedance under 0.9Ω at 1mA enabling stable regulation under varying load conditions.

It delivers specified performance across –40°C to +85°C ambient (I-grade), supports capacitive loads without oscillation, and maintains thermal hysteresis of ≤0.08% - critical for repeatable calibration in industrial measurement systems where temperature cycling occurs.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92mm × 1.30mm footprint, surface-mount, thermally efficient for PCBs with moderate power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL4050C50IDBZR and REF3050AIDBZR, the LM4040C50IDBZTG4 offers superior noise performance and true 2-pin simplicity for fixed-voltage shunt regulation, making it optimal for compact, low-power, high-accuracy analog signal chains where supply headroom is limited.

Availability

LM4040C50IDBZTG4 is available at Aetrix Electronics and suitable for analog input modules, field transmitters, and data-acquisition systems requiring stable component supply with guaranteed long-term availability and traceable lot documentation.

Supply support for LM4040C50IDBZTG4 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, embedded processing, and logic ICs, with decades of expertise in precision reference design and manufacturing.

The LM4040 series was developed specifically for high-accuracy, low-power shunt reference applications in industrial sensing, test equipment, and energy metering - emphasizing stability, noise immunity, and ease of integration.

FAQ

What is the maximum cathode current rating for LM4040C50IDBZTG4?

The absolute maximum cathode current for LM4040C50IDBZTG4 is 25mA per TI's Absolute Maximum Ratings table. However, the recommended operating range is 45μA to 15mA - exceeding 15mA risks thermal overload in the SOT-23-3 package unless board-level thermal management is implemented. The LM4040C50IDBZTG4 must remain within its 150°C junction temperature limit during continuous operation.

Does LM4040C50IDBZTG4 require an output capacitor for stability?

No, the LM4040C50IDBZTG4 is explicitly designed to be stable with all capacitive loads and does not require an output capacitor. TI confirms this in the device description and "Stable with all capacitive loads; no output capacitor required" feature bullet. Adding capacitance may even degrade transient response but will not cause oscillation - a key advantage over many older shunt references.

What is the thermal hysteresis specification for LM4040C50IDBZTG4?

The LM4040C50IDBZTG4 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 package variants, and is critical for applications requiring repeatable calibration after environmental temperature excursions, such as portable test instruments and field-deployed sensors.

How does the 100ppm/°C temperature coefficient translate to actual voltage drift over temperature?

With a 100ppm/°C coefficient and 5.0V nominal output, the LM4040C50IDBZTG4 drifts at most 0.5mV/°C. Over its full –40°C to +85°C operating range (ΔT = 125°C), maximum drift is ±62.5mV - but combined with ±25mV (±0.5%) initial tolerance, total output variation remains within ±87.5mV (±1.75%) of 5.0V, meeting industrial-grade accuracy requirements.

Is LM4040C50IDBZTG4 RoHS-compliant and lead-free?

Yes, LM4040C50IDBZTG4 is RoHS-compliant and lead-free. The "G4" suffix in the part number indicates TI's green packaging standard - Pb-free terminations, NiPdAu plating, and compliance with JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1). Full compliance documentation, including substance declarations and test reports, is available through TI's Quality & Environmental page.