Texas Instruments LM4040B20IDBZT

Overview

LM4040B20IDBZT from Texas Instruments is a precision micropower shunt voltage reference with 2.048V nominal output, ±0.2% initial accuracy (B grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current. It serves as a compact, low-noise voltage基准 in high-resolution ADC/DAC biasing and sensor signal conditioning circuits.

For engineers reviewing the LM4040B20IDBZT datasheet, LM4040B20IDBZT pinout, LM4040B20IDBZT application, or LM4040B20IDBZT equivalent, key selection criteria include guaranteed 2.048V output tolerance over –40°C to 85°C, no-output-capacitor stability, SC-70 package footprint, and compatibility with low-current portable systems requiring <100μA quiescent operation.

Technical Context

The LM4040B20IDBZT operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 2.048V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves B-grade accuracy without external components, and its low dynamic impedance (≤0.8Ω at 1mA) ensures minimal load regulation error under varying current conditions.

It functions within a fixed industrial temperature range (–40°C to +85°C), exhibits thermal hysteresis of only 0.08%, and maintains long-term stability of 120ppm after 1000 hours-enabling reliable performance in field transmitters and energy infrastructure monitoring where calibration drift must be minimized.

Key Specifications

Pinout & Package

LM4040B20IDBZT is packaged in a 3-pin SOT-23 (DBZ) case measuring 2.92mm × 1.30mm. The device uses a two-terminal shunt topology with an optional third terminal for EMI mitigation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431ACDBVR and REF3020AIDBZR, LM4040B20IDBZT offers true two-terminal simplicity and lowest noise in its class, making it optimal for space-constrained, ultra-low-power shunt reference roles where fixed 2.048V and minimal external components are mandatory.

Availability

LM4040B20IDBZT is available at Aetrix Electronics and suitable for data-acquisition systems, energy infrastructure monitoring, and field transmitter designs requiring stable component supply with guaranteed long-term availability and TI's full product lifecycle support.

Supply support for LM4040B20IDBZT 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 specifically for cost-sensitive, space-constrained applications demanding micropower operation, low noise, and robust thermal performance-targeting industrial automation, test equipment, and portable instrumentation markets.

FAQ

What is the maximum cathode current rating for LM4040B20IDBZT?

The LM4040B20IDBZT has an absolute maximum continuous cathode current of 25mA per its Absolute Maximum Ratings table. However, the recommended operating condition specifies a maximum of 15mA to ensure thermal stability and long-term reliability within the rated junction temperature limit of 150°C. Operating above 15mA requires careful thermal design and derating.

Does LM4040B20IDBZT require an output capacitor for stability?

No, LM4040B20IDBZT is inherently stable with all capacitive loads and does not require an output capacitor. Its design eliminates the need for external bypassing-unlike many series references-making it ideal for space-constrained PCB layouts where minimizing passive components is critical.

What is the purpose of Pin 3 (NC) on LM4040B20IDBZT?

Pin 3 on LM4040B20IDBZT is a no-connect terminal. It may be left floating in standard applications. Texas Instruments recommends connecting it to the anode (Pin 2) only in high-EMI environments-such as near transformers or switching regulators-to reduce noise coupling into the reference node.

How does the temperature coefficient of LM4040B20IDBZT affect system accuracy over –40°C to +85°C?

With a maximum temperature coefficient of 100ppm/°C, LM4040B20IDBZT contributes ≤±6.5mV total drift over its full industrial temperature range (ΔT = 125°C). This translates to ±0.32% of full-scale 2.048V output, which remains within the overall ±0.2% initial tolerance band when combined with thermal hysteresis and long-term drift specifications.

Can LM4040B20IDBZT replace LM4040A20IDBZT in an existing design?

Yes, LM4040B20IDBZT is a direct functional replacement for LM4040A20IDBZT in most applications, with identical pinout, package, and electrical behavior-except for relaxed initial accuracy (±0.2% vs. ±0.1%). System-level validation is recommended if the design relies on sub-2mV absolute voltage tolerance at 25°C.