Texas Instruments LM4051AIM3-1.2/NOPB

Overview

LM4051AIM3-1.2/NOPB from Texas Instruments is a precision micropower shunt voltage reference in SOT-23-3 package, delivering a fixed 1.225 V reverse breakdown voltage with ±0.1% initial tolerance (A grade), 50 ppm/°C max temperature coefficient, and 20 μV_rms noise (10 Hz–10 kHz). It operates from 60 μA to 12 mA and supports industrial (−40°C to +85°C) and extended (−40°C to +125°C) temperature ranges - ideal for high-accuracy analog sensing and low-power data acquisition.

For engineers reviewing the LM4051AIM3-1.2/NOPB datasheet, LM4051AIM3-1.2/NOPB pinout, LM4051AIM3-1.2/NOPB application, or LM4051AIM3-1.2/NOPB equivalent, key selection criteria include guaranteed 1.225 V output stability under capacitive loads, no external capacitor requirement, thermal hysteresis ≤0.36 mV/V, long-term drift of 120 ppm over 1000 hours, and compatibility with space-constrained PCB layouts using the 3.00 mm × 1.30 mm SOT-23 footprint.

Technical Context

The LM4051AIM3-1.2/NOPB implements a curvature-corrected bandgap shunt reference architecture, functioning as a precision Zener diode with internal feedback. Its regulation relies on shunting excess current to ground via the cathode terminal while maintaining stable voltage across anode-to-cathode terminals.

It operates in closed-loop mode only (fixed-output variant), requiring an external series resistor (R_S) to set operating current. The device achieves stability without output capacitance and tolerates arbitrary capacitive loading - enabled by internal compensation and low dynamic impedance (0.5 Ω at 120 Hz).

Key Specifications

Pinout & Package

LM4051AIM3-1.2/NOPB uses the DBZ (SOT-23-3) package: 3.00 mm × 1.30 mm body, 1.1 mm height, gull-wing leads. Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = NC (must float or connect to Pin 2 per TI specification).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and REF3012AIDBZR, the LM4051AIM3-1.2/NOPB uniquely combines 1.225 V fixed output, micropower operation down to 60 μA, zero-output-capacitor stability, and SOT-23-3 footprint - making it optimal for space- and power-constrained shunt reference designs where sub-1.3 V precision is mandatory.

Availability

LM4051AIM3-1.2/NOPB is available at Aetrix Electronics and suitable for portable data loggers, medical vital sign monitors, industrial process transmitters, and automotive battery management ICs requiring stable component supply across production lifecycles.

Supply support for LM4051AIM3-1.2/NOPB 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, specializing in analog, embedded processing, and digital signal processing technologies.

The LM4051-N product line delivers precision micropower shunt references for space-constrained, low-power, high-accuracy applications including portable instrumentation, medical devices, and industrial sensing - emphasizing stability without external capacitance and robust thermal performance.

FAQ

What is the exact output voltage and tolerance of LM4051AIM3-1.2/NOPB at 25°C?

The LM4051AIM3-1.2/NOPB delivers a nominal reverse breakdown voltage of 1.225 V with ±0.1% initial tolerance (A grade) at 25°C, corresponding to ±1.2 mV absolute deviation. This value is production-tested and guaranteed per TI's SNOS491D datasheet Section 6.5, and applies specifically to the LM4051AIM3-1.2/NOPB variant in SOT-23-3 packaging.

Does LM4051AIM3-1.2/NOPB require an external output capacitor for stability?

No, the LM4051AIM3-1.2/NOPB does not require an external output capacitor for stability. Its internal design ensures unconditional stability with any capacitive load, including direct connection to ADC input capacitors or op-amp feedback networks. This is confirmed in the "Features" and "Description" sections of the official TI datasheet (SNOS491D), and distinguishes LM4051AIM3-1.2/NOPB from most other shunt references.

What is the minimum operating current for LM4051AIM3-1.2/NOPB across temperature?

The LM4051AIM3-1.2/NOPB requires a minimum operating current of 60 μA over the industrial temperature range (−40°C to +85°C) and 70 μA over the extended range (−40°C to +125°C), as specified in Section 6.5 of the TI SNOS491D datasheet. This current must flow through the cathode to maintain regulation; values are grade- and temperature-dependent.

How is pin 3 used on LM4051AIM3-1.2/NOPB in the SOT-23-3 package?

Pin 3 of the LM4051AIM3-1.2/NOPB is labeled NC (No Connect) and must either be left floating or connected to pin 2 (Cathode), per TI's Pin Functions table in Section 5 of SNOS491D. It is internally tied to the die attach and not functional as a signal terminal - incorrect routing (e.g., grounding or leaving unconnected in high-noise environments) may affect thermal hysteresis or long-term stability.

What is the thermal hysteresis specification for LM4051AIM3-1.2/NOPB?

The LM4051AIM3-1.2/NOPB exhibits a thermal hysteresis of 0.36 mV/V, defined as the voltage shift measured at +25°C after cycling between −40°C and +125°C. This parameter reflects mechanical stress-induced drift in the SOT-23 package and is critical for applications requiring repeatable calibration after thermal exposure - documented in Section 6.5 of the TI SNOS491D datasheet.