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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Reference

Texas Instruments LM4051CEM3X-1.2/NOPB

Name: LM4051CEM3X-1.2/NOPB
Brand: Texas Instruments
SKU: LM4051CEM3X-1.2/NOPB
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM4051CEM3X-1.2/NOPB

Manufacturer:: Texas Instruments

Category:: Voltage Reference

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: LM4051CEM3X-1.2/NOPB.pdf

Description:: IC VREF SHUNT 0.5% SOT23-3

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Product details

Overview

LM4051CEM3X-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 ±0.5% initial tolerance (C-grade), 50 ppm/°C max temperature coefficient, 20 μV_rms noise (10 Hz–10 kHz), and stable operation from 60 μA to 12 mA supply current. It enables high-accuracy voltage regulation in space-constrained battery-powered instrumentation.

For engineers reviewing the LM4051CEM3X-1.2/NOPB datasheet, LM4051CEM3X-1.2/NOPB pinout, LM4051CEM3X-1.2/NOPB application, or LM4051CEM3X-1.2/NOPB equivalent, key selection considerations include its C-grade accuracy, SOT-23 thermal performance (R_θJA = 214.7 °C/W), no-output-capacitor requirement, capacitive-load tolerance, and −40°C to +125°C extended temperature range.

Technical Context

The LM4051CEM3X-1.2/NOPB functions as a curvature-corrected bandgap shunt reference, operating in reverse breakdown mode with internal zener-zap and fuse trimming for voltage accuracy. Its cathode-anode configuration requires only an external series resistor (R_S) to set operating current, eliminating need for output stabilization capacitors.

It maintains regulation across 60 μA–12 mA cathode current, exhibits 0.5 Ω dynamic impedance at 120 Hz, and achieves thermal hysteresis of ≤0.36 mV/V over −40°C to +125°C cycling-critical for precision data acquisition where long-term voltage stability is required.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 1.225 V reverse breakdown voltage-sets precise reference point for ADCs, DACs, and comparators without external feedback.
Initial Tolerance	±0.5% at 25°C (C-grade)-defines worst-case deviation before temperature drift; suitable for cost-sensitive industrial sensing.
Tempco	50 ppm/°C max (−40°C to +125°C)-limits total voltage drift to ±6.5 mV over full extended range, enabling stable calibration in automotive ECUs.
Noise (10 Hz–10 kHz)	20 μV_rms-low enough to avoid degrading 16-bit+ ADC effective resolution in portable medical devices.
Operating Current Range	60 μA to 12 mA-supports ultra-low-power sleep modes (<100 μA) while sustaining regulation under transient load steps.
Dynamic Impedance	0.5 Ω at 120 Hz-ensures minimal output voltage perturbation during fast load transients in energy metering front-ends.
Thermal Hysteresis	0.36 mV/V-quantifies reversible voltage shift after thermal cycling; critical for repeatable measurements in field-deployed test equipment.

Pinout & Package

SOT-23-3 (DBZ) package: 3.00 mm × 1.30 mm footprint, surface-mount, thermally optimized for PCB heat dissipation (R_θJB = 41.3 °C/W).

Pin/Terminal	Circuit Role	Design Meaning
Anode (Pin 2)	Reference ground node	Common return path for cathode current; must be connected to system ground or low-impedance reference plane.
Cathode (Pin 1)	Shunt current input / regulated output	Accepts input current via R_S; delivers stable 1.225 V relative to Anode; sinks up to 12 mA.
NC (Pin 3)	No-connect terminal	Must be left floating or tied to Pin 2 (Anode); not internally bonded-incorrect connection causes measurement error.

Key Features

Feature	Design Value
No output capacitor required	Enables direct integration into compact PCB layouts without stability-compromising bypass components-reduces BOM count by one passive.
Tolerates capacitive loads	Maintains phase margin >45° with ≥1 μF output capacitance, allowing use with ceramic decoupling caps on noisy power rails.
Reverse breakdown voltage option	Fixed 1.225 V output eliminates external resistor network-simplifies design for single-voltage references in sensor signal chains.
Extended temperature range	Rated for −40°C to +125°C operation-validates use in under-hood automotive modules and industrial motor drives without derating.
Low quiescent current	60 μA minimum operating current enables microamp-level system sleep states-extends battery life in wireless IoT nodes.

Applications

Portable Instrumentation	Data Acquisition Systems
Use Scenario: Handheld multimeter with 24-bit sigma-delta ADC requiring stable reference under varying battery voltage (2.8–4.2 V) and ambient temperature (−10°C to +50°C). IC Role / Device Role / Timing Role: Shunt voltage reference providing 1.225 V基准 for ADC internal gain stage and offset calibration. Use Value: ±0.5% initial tolerance and 50 ppm/°C tempco ensure <0.01% full-scale error drift over operating range-meets Class I accuracy standards.	Use Scenario: 16-channel industrial DAQ module sampling thermocouples and RTDs at 1 kSPS, powered from isolated 5 V rail. IC Role / Device Role / Timing Role: Precision reference for multiplexed analog front-end, shared across channel-specific PGA and anti-alias filters. Use Value: 20 μV_rms broadband noise prevents degradation of ENOB below 15.2 bits; 0.5 Ω dynamic impedance minimizes crosstalk between channels during switching.
Energy Management	Medical Monitoring
Use Scenario: Smart electricity meter with metrology ASIC measuring active/reactive power in residential grid interface. IC Role / Device Role / Timing Role: Reference for metrology ADC and voltage scaling circuitry in Class 0.5 revenue-grade metering. Use Value: Thermal hysteresis ≤0.36 mV/V ensures repeatable calibration after seasonal temperature cycling-maintains ANSI C12.20 compliance over 10-year field life.	Use Scenario: Portable ECG monitor with dry-electrode front-end, operating from coin-cell battery for ≥72 hours per charge. IC Role / Device Role / Timing Role: Low-power reference for analog signal conditioning and lead-off detection circuitry. Use Value: 60 μA minimum operating current allows continuous reference bias during deep-sleep MCU states-enables rapid wake-up without reference settling delay.

Portable Instrumentation

Data Acquisition Systems

Use Scenario: Handheld multimeter with 24-bit sigma-delta ADC requiring stable reference under varying battery voltage (2.8–4.2 V) and ambient temperature (−10°C to +50°C).

IC Role / Device Role / Timing Role: Shunt voltage reference providing 1.225 V基准 for ADC internal gain stage and offset calibration.

Use Value: ±0.5% initial tolerance and 50 ppm/°C tempco ensure <0.01% full-scale error drift over operating range-meets Class I accuracy standards.

Use Scenario: 16-channel industrial DAQ module sampling thermocouples and RTDs at 1 kSPS, powered from isolated 5 V rail.

IC Role / Device Role / Timing Role: Precision reference for multiplexed analog front-end, shared across channel-specific PGA and anti-alias filters.

Use Value: 20 μV_rms broadband noise prevents degradation of ENOB below 15.2 bits; 0.5 Ω dynamic impedance minimizes crosstalk between channels during switching.

Energy Management

Medical Monitoring

Use Scenario: Smart electricity meter with metrology ASIC measuring active/reactive power in residential grid interface.

IC Role / Device Role / Timing Role: Reference for metrology ADC and voltage scaling circuitry in Class 0.5 revenue-grade metering.

Use Value: Thermal hysteresis ≤0.36 mV/V ensures repeatable calibration after seasonal temperature cycling-maintains ANSI C12.20 compliance over 10-year field life.

Use Scenario: Portable ECG monitor with dry-electrode front-end, operating from coin-cell battery for ≥72 hours per charge.

IC Role / Device Role / Timing Role: Low-power reference for analog signal conditioning and lead-off detection circuitry.

Use Value: 60 μA minimum operating current allows continuous reference bias during deep-sleep MCU states-enables rapid wake-up without reference settling delay.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL431CDBZR	2.495 V adjustable reference; higher 100 μA min current; 2% initial tolerance; SO-8 package	Requires external resistors for 1.225 V setting; unsuitable for ultra-low-power designs due to higher quiescent current	Select TL431CDBZR only when 2.5 V reference is acceptable and board space permits SO-8 footprint.
REF3012AIDBZR	1.2 V series reference; 0.2% initial tolerance (A-grade); 50 ppm/°C tempco; 50 μA typical quiescent current	Series topology requires dedicated supply rail; cannot sink current like shunt device-unsuitable for current-source or clamping topologies	Choose REF3012AIDBZR for low-noise series-regulated supplies where load current exceeds 1 mA and sinking capability is unnecessary.

Compared with TL431CDBZR and REF3012AIDBZR, the LM4051CEM3X-1.2/NOPB uniquely combines fixed 1.225 V output, sub-100 μA operation, SOT-23 size, and true shunt functionality-making it optimal for space- and power-constrained clamping, current-sensing, and precision biasing circuits where sinking capability is essential.

Availability

LM4051CEM3X-1.2/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, industrial data acquisition, and energy management systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM4051CEM3X-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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in precision analog ICs and reference design support.

The LM4051-N product line delivers micropower shunt voltage references optimized for space-constrained, battery-operated, and high-accuracy measurement systems-including portable test equipment, industrial sensors, and automotive subsystems.

FAQ

What is the guaranteed temperature coefficient specification for LM4051CEM3X-1.2/NOPB over its full operating range?

The LM4051CEM3X-1.2/NOPB has a maximum temperature coefficient of 50 ppm/°C across the extended temperature range of −40°C to +125°C. This value is guaranteed for all grades (A/B/C) and defines the worst-case voltage drift per degree Celsius, resulting in a total overtemperature tolerance of ±0.825% for the C-grade device. The specification is validated using Statistical Quality Control methods and applies to both industrial and extended temperature conditions.

Can LM4051CEM3X-1.2/NOPB operate stably without an output capacitor, and what is the evidence?

Yes, the LM4051CEM3X-1.2/NOPB is explicitly designed to operate stably without any output capacitor. The datasheet confirms this in multiple sections: the "Features" list states "No Output Capacitor Required", the "Description" notes its "advanced design eliminates the need for an external stabilizing capacitor", and the "Detailed Description" section affirms stable operation "without the need of an external capacitor connected between the '+' pin and the '−' pin". This behavior is enabled by internal compensation and verified across all load and current conditions.

What is the function of Pin 3 (NC) on LM4051CEM3X-1.2/NOPB, and how must it be handled in layout?

Pin 3 of the LM4051CEM3X-1.2/NOPB is a no-connect (NC) terminal with no internal bond wire. Per the official datasheet Pin Functions table and DBZ package diagrams, it "must be left floating or connected to pin 2" (Anode). In PCB layout, it should either remain unconnected or be shorted directly to Pin 2 using a low-inductance trace-never tied to cathode, supply, or signal nets, as improper connection introduces measurement uncertainty and violates TI's recommended usage.

How does the minimum operating current of LM4051CEM3X-1.2/NOPB vary with temperature, and what is its value at −40°C?

The minimum operating current for LM4051CEM3X-1.2/NOPB increases with decreasing temperature. At −40°C (minimum rated temperature), the C-grade device requires 65 μA to maintain regulation-5 μA higher than its 60 μA value at 25°C. This is specified in Section 6.5 "LM4051-1.2 Electrical Characteristics" under IR_MIN for the "Industrial Temp. Range" row, and reflects increased junction resistance at cold temperatures. Designers must size R_S to guarantee ≥65 μA under worst-case cold-start conditions.

Is LM4051CEM3X-1.2/NOPB suitable for use in automotive under-hood applications, and which qualification supports this?

Yes, the LM4051CEM3X-1.2/NOPB is qualified for automotive under-hood use via its extended temperature rating of −40°C to +125°C and guaranteed 50 ppm/°C tempco across that full range. While not AEC-Q200 certified as a standalone component, its electrical specifications-including thermal hysteresis (0.36 mV/V), long-term stability (120 ppm), and robust ESD ratings (±2000 V HBM)-align with requirements for engine control, transmission, and body electronics. System-level validation per ISO/TS 16949 remains the responsibility of the end customer.

LM4051CEM3X-1.2/NOPB Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Package/Case:: TO-236-3, SC-59, SOT-23-3

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Discontinued at Digi-Key

Reference Type:: Shunt

Output Type:: Fixed

Voltage - Output (Min/Fixed):: 1.225V

Voltage - Output (Max):: -

Current - Output:: 12 mA

Tolerance:: ±0.5%

Temperature Coefficient:: 50ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: 20µVrms

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 65 µA

Operating Temperature:: -40°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

LM4051CEM3X-1.2/NOPB FAQ

1.How can I place an order for LM4051CEM3X-1.2/NOPB through Aetrix?

Please submit a Request for Quotation (RFQ) for LM4051CEM3X-1.2/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LM4051CEM3X-1.2/NOPB reliable?

The price and inventory of LM4051CEM3X-1.2/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4051CEM3X-1.2/NOPB is usually 5 days.

3.What payment methods are accepted for LM4051CEM3X-1.2/NOPB?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4051CEM3X-1.2/NOPB transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM4051CEM3X-1.2/NOPB?

LM4051CEM3X-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM4051CEM3X-1.2/NOPB order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LM4051CEM3X-1.2/NOPB?

For technical support, including LM4051CEM3X-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4051CEM3X-1.2/NOPB requirements.

6.How does Aetrix verify that LM4051CEM3X-1.2/NOPB is sourced from the original manufacturer or authorized distributors?

All LM4051CEM3X-1.2/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM4051CEM3X-1.2/NOPB meets industry standards.

7.What is the process for return or replacement of LM4051CEM3X-1.2/NOPB?

All LM4051CEM3X-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM4051CEM3X-1.2/NOPB, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LM4051CEM3X-1.2/NOPB part is unused and in its original packaging.

Return procedure for LM4051CEM3X-1.2/NOPB:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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