Texas Instruments LM4040DIM3-2.5

Overview

LM4040DIM3-2.5 from Texas Instruments is a precision micropower shunt voltage reference in SOT-23-3 package, delivering a stable 2.5 V reverse breakdown voltage with ±0.5% initial tolerance (D grade), 100 ppm/°C max temperature coefficient, 65 μA min operating current, and 35 μV_rms wideband noise (10 Hz–10 kHz). It serves as a compact, capacitor-tolerant reference for ADC biasing and sensor excitation in portable instrumentation.

For engineers reviewing the LM4040DIM3-2.5 datasheet, LM4040DIM3-2.5 pinout, LM4040DIM3-2.5 application, or LM4040DIM3-2.5 equivalent, this page delivers verified specifications, validated SOT-23 pin functions, real-world use cases in battery-powered data acquisition and automotive energy management, and two confirmed alternative parts with documented technical and application differences.

Technical Context

The LM4040DIM3-2.5 operates as a two-terminal shunt reference, sinking current through its cathode to maintain a precise 2.5 V across its anode–cathode terminals. Its Zener-zap trimmed bandgap architecture achieves ±0.5% initial accuracy at 25°C and supports operation from −40°C to +85°C (industrial grade).

It requires no output capacitor and remains stable with capacitive loads up to 10 nF. Dynamic impedance is ≤1.1 Ω at 1 mA, enabling low-noise performance in high-resolution analog signal chains where supply rejection and thermal hysteresis (≤0.08%) are critical.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92 mm × 1.30 mm body, surface-mount, JEDEC-compliant footprint with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and MAX6008AEUR+T, the LM4040DIM3-2.5 offers optimal balance of SOT-23 thermal robustness, fixed-pin simplicity, and D-grade cost-performance for industrial data acquisition - avoiding resistor networks while supporting higher continuous current than SC70 alternatives.

Availability

LM4040DIM3-2.5 is available at Aetrix Electronics and suitable for portable instrumentation, automotive cabin sensors, and industrial process transmitters requiring stable component supply with guaranteed long-term continuity.

Supply support for LM4040DIM3-2.5 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 automotive-qualified components.

The LM4040-N product line delivers micropower shunt references optimized for space-constrained, battery-operated, and industrial sensing applications where stability, low noise, and minimal external components are mandatory.

FAQ

What is the maximum operating current for LM4040DIM3-2.5?

The LM4040DIM3-2.5 supports a maximum operating current of 15 mA across its full industrial temperature range (−40°C to +85°C). This rating is defined in Section 6.3 of the TI datasheet (SNOS633K) and reflects the device's ability to dissipate heat in the SOT-23 package without exceeding junction temperature limits. Exceeding 15 mA risks thermal shutdown or long-term reliability degradation. The LM4040DIM3-2.5 must be used within this limit to ensure specified voltage accuracy and stability.

Does LM4040DIM3-2.5 require an output capacitor for stability?

No, the LM4040DIM3-2.5 does not require an output capacitor for stability. Its internal design eliminates the need for external stabilization, and it remains stable even with capacitive loads up to 10 nF at the cathode. This is explicitly stated in the "Features" section and validated in the "Application and Implementation" chapter of the TI datasheet. Adding a capacitor is optional and only recommended for specific noise-filtering purposes-not for stability assurance. The LM4040DIM3-2.5 maintains regulation integrity under all tested capacitive loading conditions.

What is the temperature coefficient specification for LM4040DIM3-2.5?

The LM4040DIM3-2.5 has a maximum average temperature coefficient of 100 ppm/°C over the industrial temperature range (−40°C to +85°C), as confirmed in Section 6.8 of the TI datasheet. This value applies to the D-grade variant and defines the worst-case voltage drift per degree Celsius relative to the 25°C reference point. At ±0.5% initial tolerance, this results in a total overtemperature tolerance of ±19 mV across the full range - a key parameter for high-accuracy sensor signal conditioning where thermal drift must be bounded.

Can LM4040DIM3-2.5 be used in automotive applications?

The LM4040DIM3-2.5 is rated for industrial temperature range (−40°C to +85°C) and is not AEC-Q200 qualified. For automotive applications requiring qualification, TI offers the LM4040-N-Q1 series (e.g., LM4040QAIM3-2.5), which carries AEC-Q200 Grade 3 certification and extended temperature support. Using LM4040DIM3-2.5 in automotive environments may violate functional safety requirements unless fully validated per ISO 26262. Always select the Q1 variant - not LM4040DIM3-2.5 - for production automotive ECUs or cabin modules.

What is the function of Pin 3 (NC) on LM4040DIM3-2.5?

Pin 3 of the LM4040DIM3-2.5 is a no-connect (NC) terminal, internally unconnected and electrically isolated. Per TI's Pin Functions table (Section 5), it must either be left floating or tied to Pin 2 (Anode); it must never be connected to cathode, supply, or any active node. Misconnecting Pin 3 can cause unpredictable behavior or damage. This NC designation is consistent across all SOT-23 variants of the LM4040-N family and is not a placeholder for future functionality - the LM4040DIM3-2.5 operates fully as a two-terminal device using only Pins 1 and 2.