Texas Instruments LM4040B25IDBZTG4

Overview

LM4040B25IDBZTG4 from Texas Instruments is a precision 2.5V shunt voltage reference in SOT-23-3 (DBZ) package, rated for industrial temperature range (–40°C to +85°C), with ±0.2% initial accuracy, 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation down to 45μA cathode current. It serves as a low-power, high-stability reference in analog-to-digital converters and sensor signal conditioning circuits.

For engineers reviewing the LM4040B25IDBZTG4 datasheet, LM4040B25IDBZTG4 pinout, LM4040B25IDBZTG4 application, or LM4040B25IDBZTG4 equivalent, key selection criteria include output tolerance at 25°C, thermal drift over –40°C to +85°C, minimum operating current, dynamic impedance, and compatibility with capacitive loads without external compensation.

Technical Context

The LM4040B25IDBZTG4 operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 2.5V reverse breakdown voltage across its terminals. Its Zener-zap trimmed bandgap architecture delivers tight initial tolerance and low temperature coefficient without requiring external components.

It exhibits low dynamic impedance (0.8Ω typical at 1mA), supports cathode currents from 45μA to 15mA, and remains stable with any capacitive load - eliminating need for output capacitance. Thermal hysteresis is limited to 0.08%, and long-term stability is 120ppm after 1000 hours.

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 LM4040C25IDBZTG4, the LM4040B25IDBZTG4 offers 2.5× tighter initial tolerance at identical package and operating current; compared with REF3025AIDBZR, it eliminates output capacitor requirements and supports lower minimum current, simplifying layout at the expense of slightly higher tempco.

Availability

LM4040B25IDBZTG4 is available at Aetrix Electronics and suitable for industrial data acquisition, field transmitter design, and energy infrastructure monitoring requiring stable component supply with guaranteed long-term sourcing.

Supply support for LM4040B25IDBZTG4 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM4040 series was designed specifically for precision, low-power shunt reference applications in space-constrained and thermally demanding environments - emphasizing micropower operation, wide current range, and robust capacitive-load stability.

FAQ

What is the maximum cathode current rating for LM4040B25IDBZTG4?

The absolute maximum cathode current for LM4040B25IDBZTG4 is 25mA, per TI's Absolute Maximum Ratings. However, the recommended operating range is 45μA to 15mA. Operating above 15mA increases self-heating and may degrade long-term stability and accuracy, especially in high ambient temperatures or poor PCB thermal dissipation.

Does LM4040B25IDBZTG4 require an output capacitor for stability?

No, LM4040B25IDBZTG4 is inherently stable with all capacitive loads and does not require an output capacitor. This is confirmed in the device description and "Features" section of the datasheet. Adding capacitance does not harm performance but provides no stability benefit - simplifying layout and reducing component count in compact designs.

What is the thermal hysteresis specification for LM4040B25IDBZTG4?

The thermal hysteresis of LM4040B25IDBZTG4 is 0.08%, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to +125°C. This value applies across all grades and packages, and directly impacts repeatability in systems subject to repeated thermal cycling, such as outdoor energy meters or automotive ECUs.

Can LM4040B25IDBZTG4 be used in automotive applications?

LM4040B25IDBZTG4 is qualified for the industrial temperature range (–40°C to +85°C), not the full automotive AEC-Q100 Grade 1 (–40°C to +125°C) range. While it may function in some under-hood or cabin applications, TI does not certify it for automotive use. For automotive battery monitors or ADAS sensors, LM4040B25IDBZTG4 should be validated per system-level requirements and derated accordingly.

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

For LM4040B25IDBZTG4, a 100ppm/°C coefficient means the output voltage changes by up to 0.25mV/°C (100 × 10⁻⁶ × 2.5V). Over the full –40°C to +85°C range (ΔT = 125°C), worst-case drift is ±15.6mV - but the datasheet specifies total overtemperature tolerance of ±0.85% (±21.25mV) including initial error, making the 100ppm/°C value a key contributor to that bound.