Texas Instruments LM4040C20IDBZTG4

Overview

LM4040C20IDBZTG4 from Texas Instruments is a precision micropower shunt voltage reference with 2.048V nominal output, ±0.5% initial accuracy (C grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current. It serves as a compact, low-drift reference in analog-to-digital converters and sensor signal conditioning circuits.

For engineers reviewing the LM4040C20IDBZTG4 datasheet, LM4040C20IDBZTG4 pinout, LM4040C20IDBZTG4 application, or LM4040C20IDBZTG4 equivalent, key selection criteria include its SOT-23-3 package, industrial temperature range (–40°C to +85°C), no-output-capacitor requirement, and compatibility with high-impedance sensing nodes in portable instrumentation.

Technical Context

The LM4040C20IDBZTG4 operates as a two-terminal shunt reference, sinking cathode current to maintain a precise 2.048V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves ±0.5% initial tolerance and 100ppm/°C thermal drift over –40°C to +85°C.

It delivers 35μVRMS noise (10Hz–10kHz) at 100μA bias, exhibits ≤0.9Ω dynamic impedance at 1mA, and remains stable with any capacitive load - eliminating need for external output capacitance. Minimum operating current is 45μA typical, supporting ultra-low-power applications.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92mm × 1.30mm footprint, surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C20IDBZTG4, LM4040C20IDCKR offers identical performance in a smaller footprint but requires different land pattern and stencil design, while REF3020AIDBZR provides tighter initial accuracy and superior supply rejection at the cost of added external components and inability to operate as a true two-terminal device.

Availability

LM4040C20IDBZTG4 is available at Aetrix Electronics and suitable for data-acquisition systems, analog input modules, and energy infrastructure applications requiring stable component supply, long-lifecycle support, and traceable industrial-grade sourcing.

Supply support for LM4040C20IDBZTG4 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM4040 series was designed as a family of precision micropower shunt references targeting portable instrumentation, sensor interfaces, and industrial data converters where size, power, and stability are critical.

FAQ

What is the operating temperature range for LM4040C20IDBZTG4?

The LM4040C20IDBZTG4 is specified for industrial temperature operation from –40°C to +85°C. This range is validated per TI's characterization data for the "I" suffix variant and supports deployment in factory automation, outdoor metering, and industrial control environments where ambient extremes are expected. The C-grade tolerance and 100ppm/°C coefficient apply across this full range.

Does LM4040C20IDBZTG4 require an output capacitor?

No, LM4040C20IDBZTG4 does not require an output capacitor. Its internal design ensures stability with all capacitive loads - including 0μF - making it ideal for space-constrained or ultra-low-power applications where minimizing external components is essential. This behavior is explicitly guaranteed in the datasheet and verified across process corners and temperature.

What is the minimum cathode current needed for LM4040C20IDBZTG4 to regulate?

The LM4040C20IDBZTG4 requires a minimum cathode current of 45μA (typical) at 25°C to maintain regulation. At full temperature range (–40°C to +85°C), the maximum required minimum current is 80μA. This low threshold enables use with high-value bias resistors - for example, a 24V supply with a 511kΩ resistor delivers ~47μA, sufficient for stable operation.

How does the noise performance of LM4040C20IDBZTG4 impact precision ADC designs?

LM4040C20IDBZTG4 delivers 35μVRMS wideband noise (10Hz–10kHz), which directly contributes to the reference noise term in ADC effective number of bits (ENOB). For a 2.048V reference used with a 24-bit delta-sigma ADC, this noise supports ≥16-bit ENOB in well-designed front-ends and is significantly lower than many competing shunt references, preserving dynamic range in high-resolution measurements.

Is LM4040C20IDBZTG4 pin-compatible with other LM4040 variants in SOT-23-3?

Yes, LM4040C20IDBZTG4 is pin-compatible with all LM4040x20I variants in the DBZ (SOT-23-3) package, including LM4040A20IDBZTG4, LM4040B20IDBZTG4, and LM4040D20IDBZTG4. Pin 1 is Cathode, Pin 2 is Anode, and Pin 3 is NC across all grades - allowing direct substitution when accuracy or temperature coefficient requirements change within the same package.