Texas Instruments LM4040B25IDBZR

Overview

LM4040B25IDBZR from Texas Instruments is a precision 2.5V shunt voltage reference in SOT-23-3 (DBZ) package, delivering ±0.2% initial accuracy, 100ppm/°C temperature coefficient, 35μVRMS wideband noise, 45μA minimum cathode current, and stable operation across –40°C to 85°C - used for high-accuracy ADC/DAC biasing and sensor signal conditioning in industrial data-acquisition modules.

For engineers reviewing the LM4040B25IDBZR datasheet, LM4040B25IDBZR pinout, LM4040B25IDBZR application, or LM4040B25IDBZR equivalent, key selection criteria include guaranteed 2.5V output tolerance over temperature, low-noise performance at microamp-level operating current, compatibility with all capacitive loads without external compensation, and qualification for extended industrial ambient conditions.

Technical Context

The LM4040B25IDBZR operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 2.5V reverse breakdown voltage (VZ) across its terminals. Its Zener-zap trimmed bandgap architecture ensures tight initial tolerance and low thermal drift without requiring external components.

It exhibits 0.3Ω typical dynamic impedance (ZZ) at 1mA, supports cathode current from 45μA to 15mA, and maintains stable regulation even with unlimited capacitive loading - eliminating need for output bypass capacitors in space-constrained portable or field-transmitter designs.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92mm × 1.30mm footprint, surface-mount, thermally enhanced plastic case rated for 206°C/W junction-to-ambient resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C25IDBZR, the LM4040B25IDBZR provides 0.3% tighter initial tolerance at identical price and package; versus REF3025AIDBZR, it offers shunt simplicity and micropower operation but trades off ultimate temperature stability.

Availability

LM4040B25IDBZR is available at Aetrix Electronics and suitable for industrial data-acquisition systems, field transmitters, and energy infrastructure monitoring requiring stable component supply with guaranteed long-term availability and traceable lot history.

Supply support for LM4040B25IDBZR 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 family was engineered for cost-sensitive, space-constrained applications demanding high accuracy without external components - targeting industrial automation, test equipment, and portable instrumentation markets.

FAQ

What is the maximum cathode current rating for LM4040B25IDBZR?

The LM4040B25IDBZR has an absolute maximum cathode current (IZ) rating of 25mA per its datasheet Absolute Maximum Ratings table. However, the recommended operating condition specifies a maximum of 15mA to ensure thermal stability and long-term reliability within the SOT-23-3 package's 206°C/W thermal resistance limit. Exceeding 15mA risks junction temperature rise beyond 150°C under typical PCB conditions, potentially degrading long-term voltage stability. Always verify power dissipation (P = VZ × IZ) against ambient temperature and layout.

Does LM4040B25IDBZR require an output capacitor for stability?

No, the LM4040B25IDBZR is explicitly designed to be stable with all capacitive loads and does not require an output capacitor. Its internal architecture provides unconditional stability regardless of load capacitance value or ESR, eliminating the need for external compensation components. This simplifies layout, reduces BOM count, and improves reliability in applications such as portable sensors or densely routed PCBs where capacitor placement is constrained.

What is the thermal hysteresis specification for LM4040B25IDBZR?

The LM4040B25IDBZR 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 low hysteresis ensures repeatable 2.5V output behavior during repeated thermal excursions - critical for field-deployed equipment subject to diurnal temperature swings or intermittent high-load operation. The value is consistent across all LM4040 grades and package variants.

Can LM4040B25IDBZR operate at –40°C to 125°C?

No - the LM4040B25IDBZR is rated for operation from –40°C to +85°C (industrial temperature range). For extended temperature operation up to 125°C, TI offers the LM4040B25QDBZR variant (Q-grade), which shares identical electrical specifications but is characterized and qualified across –40°C to 125°C. Using the I-grade part outside its specified range may result in parametric degradation or failure, particularly in temperature coefficient and long-term stability.

How does the LM4040B25IDBZR compare to the A-grade version LM4040A25IDBZR?

The LM4040B25IDBZR offers ±0.2% initial accuracy versus ±0.1% for the LM4040A25IDBZR, with identical 100ppm/°C temperature coefficient, 35μVRMS noise, and 45μA minimum cathode current. The B-grade provides 2× the initial tolerance margin at lower cost while maintaining full compatibility in pinout, package, and application circuitry - making it ideal for applications where 0.2% absolute accuracy meets system requirements without premium pricing.