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Texas Instruments LM4040C30QDBZR — Analog & Data Acquisition

LM4040C30QDBZR Shunt Voltage Reference, 3 V ±0.5%, SOT-23-3

MPNLM4040C30QDBZR
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Texas Instruments LM4040C30QDBZR, precision micropower shunt voltage reference, fixed 3 V output, ±0.5% tolerance, 35 µVrms noise, 100 ppm/°C drift, -40°C to 125°C, SOT-23-3 package, Tape & Reel.

$1.3100Ref. price · indicative, final on quote
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

LM4040C30QDBZR specifications
ParameterValue
Output typeFixed
MountingSurface Mount
Reference typeShunt
Voltage - output (Min (Fixed))3V
Output current15 mA
Current - cathode82 µA
Operating temperature-40°C~125°C(TA)
PackageTape & Reel (TR); Cut Tape (CT)
Tolerance±0.5%
CaseTO-236-3, SC-59, SOT-23-3
Noise - 10Hz to 10kHz35µVrms
Temperature coefficient100ppm/°C

Product details

3 V shunt reference for precision bias and ADC rails

The shunt topology means it behaves like a two-terminal Zener: you set the cathode current with a single series resistor from the supply rail. The 82 µA minimum cathode current allows it to run from a high-impedance bias, and the 15 mA maximum output current gives headroom for driving a single ADC reference input or a comparator threshold divider.

Wideband noise is specified at 35 µVrms over the 10 Hz to 10 kHz band. For a 3 V reference feeding a 12-bit ADC with a 3 V full-scale range, that noise floor contributes roughly 0.5 LSB of uncertainty — acceptable for most industrial measurements but worth derating if you are pushing 14-bit resolution without averaging. Temperature drift is rated at 100 ppm/°C. That matters if your system calibrates at room temperature and then sees a 60°C rise inside the enclosure — the drift budget eats into the ADC's usable code range.

Frequently asked questions

What is the tolerance of LM4040C30QDBZR?

Initial tolerance is ±0.5% at 25°C. That is a mid-grade precision tier — tight enough for 8- to 10-bit ADC references without external trimming, but not the ±0.1% grade needed for 12-bit-plus systems.

What package does LM4040C30QDBZR come in?

It is supplied in a SOT-23-3 surface-mount package (also listed as TO-236-3 / SC-59). The shipping medium is Tape & Reel or Cut Tape.

Can LM4040C30QDBZR replace LM4040A30?

Both are 3 V shunt references in the same LM4040 family. The 'C' grade denotes ±0.5% tolerance, while the 'A' grade is ±0.1%. They are pin-compatible in the same SOT-23-3 footprint, so a direct replacement is possible if the tighter tolerance of the 'A' grade is not required for your application.