Texas Instruments LM4040D41IDBZR

Overview

LM4040D41IDBZR from Texas Instruments is a precision micropower shunt voltage reference with a fixed 4.096V output, D-grade (±1.0% initial tolerance, 150ppm/°C tempco), rated for –40°C to 85°C operation, packaged in SOT-23-3 (DBZ), and designed for high-accuracy analog sensing and data acquisition where low quiescent current (45μA typical) and low noise (35μVRMS) are critical.

For engineers reviewing the LM4040D41IDBZR datasheet, LM4040D41IDBZR pinout, LM4040D41IDBZR application, or LM4040D41IDBZR equivalent, key selection factors include its 4.096V nominal output, D-grade accuracy and temperature coefficient, SOT-23-3 package compatibility, stable operation without output capacitor, and suitability for space-constrained industrial and automotive sensor signal conditioning.

Technical Context

The LM4040D41IDBZR 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 and Zener-zap trimming to achieve specified initial tolerance and temperature coefficient, with dynamic impedance under 1.1Ω at 1mA enabling stable regulation across load and supply variations.

It requires no external capacitor for stability and maintains performance over a wide cathode current range (45μA to 15mA). The device's thermal hysteresis is 0.08%, and long-term stability is 120ppm after 1000 hours - critical for calibration-critical systems where drift must be minimized over time and temperature cycling.

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 TL4050C41IDBZR and REF3040AIDBZR, the LM4040D41IDBZR offers lowest cost and smallest footprint for non-calibrated industrial sensing, trading accuracy for micropower simplicity and capacitor-free operation - ideal when system-level calibration compensates for initial tolerance.

Availability

LM4040D41IDBZR is available at Aetrix Electronics and suitable for industrial sensor transmitters, portable data loggers, automotive cabin sensors, and energy meter analog front-ends requiring stable component supply with guaranteed long-term sourcing.

Supply support for LM4040D41IDBZR 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 company specializing in analog and embedded processing technologies, with leadership in precision analog ICs and broad industrial portfolio coverage.

The LM4040 series is part of TI's precision voltage reference product line, engineered for cost-sensitive, space-constrained applications demanding micropower operation, low noise, and robust thermal performance without external components.

FAQ

What is the nominal output voltage of the LM4040D41IDBZR?

The LM4040D41IDBZR has a nominal output voltage of 4.096V, selected to align precisely with 12-bit analog-to-digital converter full-scale ranges (4096 steps × 1mV/step). This value is trimmed during wafer sort and guaranteed within ±1.0% at 25°C per the D-grade specification. The 4.096V output remains stable across cathode currents from 45μA to 15mA and temperatures from –40°C to 85°C.

Does the LM4040D41IDBZR require an external output capacitor?

No, the LM4040D41IDBZR does not require an external output capacitor. It is inherently stable with all capacitive loads, including zero capacitance, due to its shunt topology and internal design. This eliminates BOM cost, reduces PCB area, and avoids potential instability issues associated with capacitor ESR and ESL - a key advantage over many series references like the REF3040AIDBZR.

What is the minimum cathode current needed for regulation in the LM4040D41IDBZR?

The LM4040D41IDBZR requires a minimum cathode current of 45μA (typical) to maintain regulation. This value is specified at 25°C and increases slightly over temperature (up to 80μA across –40°C to 85°C). Designers must ensure the bias network delivers ≥45μA under worst-case conditions - for example, using a resistor calculated as (VS – 4.096V) / 45μA, where VS is the minimum supply voltage.

How does the temperature coefficient affect accuracy of the LM4040D41IDBZR over its operating range?

The LM4040D41IDBZR has a maximum temperature coefficient of 150ppm/°C. Over its full operating range (–40°C to 85°C, ΔT = 125°C), this contributes up to ±0.1875% additional error (150ppm × 125) beyond the ±1.0% initial tolerance. Combined with initial error, the total voltage deviation remains within ±1.2% - sufficient for industrial sensing where system calibration corrects residual drift.

Is the LM4040D41IDBZR pin-compatible with other LM4040 variants in SOT-23-3?

Yes, the LM4040D41IDBZR is pin-compatible with all LM4040x41I variants in the SOT-23-3 (DBZ) package, including LM4040A41IDBZR, LM4040B41IDBZR, and LM4040C41IDBZR. Pin 1 is Cathode, Pin 2 is Anode, and Pin 3 is NC - identical across grades and output voltages in this package. This allows direct substitution for accuracy upgrades or cost-down without PCB changes.