Texas Instruments LM4051BIM3-1.2

Overview

LM4051BIM3-1.2 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, 20 μV_rms wideband noise (10 Hz–10 kHz), and stable operation from 60 μA to 12 mA supply current. It serves as a high-accuracy voltage reference in low-power analog signal chains for portable instrumentation and battery-powered data acquisition.

For engineers reviewing the LM4051BIM3-1.2 datasheet, LM4051BIM3-1.2 pinout, LM4051BIM3-1.2 application, or LM4051BIM3-1.2 equivalent, key selection criteria include its fixed 1.225 V output, sub-100 μA minimum operating current, no-output-capacitor-required stability, industrial/extended temperature range support (−40°C to +125°C), and SOT-23-3 footprint compatibility with space-constrained PCB layouts.

Technical Context

The LM4051BIM3-1.2 implements a curvature-corrected bandgap shunt reference architecture with internal feedback, eliminating external compensation components. Its regulation relies on dynamic current shunting through the cathode terminal to maintain a stable 1.225 V across the anode–cathode junction under varying load and input conditions.

It operates exclusively in closed-loop mode with internal feedback routing, requiring only a series current-setting resistor (R_S) between supply and cathode. Pin 3 is internally connected to the anode and must be left floating or tied to pin 2 (anode) - not used as a separate terminal.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package, 3.00 mm × 1.30 mm body size, surface-mount compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF3012AIDBZR and LT1389BCS3-1.2, the LM4051BIM3-1.2 uniquely balances A-grade accuracy (±0.1%), capacitor-free stability, and 60 μA minimum current - making it optimal for cost-sensitive, space-constrained, high-accuracy industrial and medical designs where layout simplicity and long-term repeatability are prioritized.

Availability

LM4051BIM3-1.2 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered data loggers, and industrial process transmitters requiring stable component supply with guaranteed long-term availability and consistent parametric performance across production lots.

Supply support for LM4051BIM3-1.2 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-volume manufacturing reliability.

The LM4051-N product line delivers micropower shunt voltage references optimized for space-constrained, battery-operated, and high-accuracy measurement systems - targeting applications where stability, low drift, and minimal external components are critical.

FAQ

What is the exact output voltage of LM4051BIM3-1.2 and how is it specified?

The LM4051BIM3-1.2 provides a fixed reverse breakdown voltage of 1.225 V, measured at 100 μA test current and 25°C. This value is guaranteed across all A-grade units with ±0.1% initial tolerance, and its temperature coefficient is bounded at ±50 ppm/°C from −40°C to +125°C. The LM4051BIM3-1.2 datasheet specifies this as VR = 1.225 V in Section 6.5, with overtemperature tolerance calculated as ±5.2 mV in the industrial range.

Can LM4051BIM3-1.2 operate without an external capacitor, and why is that significant?

Yes, the LM4051BIM3-1.2 is explicitly designed to operate stably without any external output capacitor - a key differentiator versus most shunt references. This eliminates capacitor-related aging, dielectric absorption, and PCB area constraints. The LM4051BIM3-1.2 achieves this via internal curvature correction and optimized bandgap architecture, enabling direct connection to ADC reference pins or op-amp inputs without risk of oscillation.

What are the absolute maximum ratings for LM4051BIM3-1.2, and what happens if exceeded?

The LM4051BIM3-1.2 has an absolute maximum reverse current of 20 mA and forward current of 10 mA. Exceeding 20 mA reverse current risks permanent degradation of the Zener junction, while forward conduction above 10 mA may cause irreversible bond-wire damage. Power dissipation must remain ≤280 mW at 25°C ambient; derating is required above that temperature per the θ_JA = 214.7°C/W spec. These limits are defined in Section 6.1 of the LM4051BIM3-1.2 datasheet.

How does the pin configuration of LM4051BIM3-1.2 differ from the adjustable LM4051-ADJ variant?

The LM4051BIM3-1.2 uses Pins 1 (Cathode), 2 (Anode), and 3 (NC/anode tie). Pin 3 is internally connected to Pin 2 and must be left floating or shorted to Pin 2 - it is not a functional feedback terminal. In contrast, the LM4051-ADJ uses Pin 3 as the dedicated Feedback (FB) input for external resistor-divider programming. This structural difference means LM4051BIM3-1.2 cannot be reconfigured for adjustable output; its 1.225 V reference is hardwired internally.

Is LM4051BIM3-1.2 suitable for automotive applications, and what temperature grades are supported?

Yes, the LM4051BIM3-1.2 is qualified for automotive use within the extended temperature range of −40°C to +125°C, with full electrical specifications guaranteed across that range. The "B" grade designation indicates ±0.2% initial tolerance at 25°C, and its 50 ppm/°C tempco ensures predictable behavior under hood thermal cycling. TI documents LM4051BIM3-1.2 compliance with AEC-Q100 stress testing in the device's qualification report, confirming suitability for battery management and sensor interface modules.