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

Texas Instruments LM4040C50QDBZTG4

Name: LM4040C50QDBZTG4
Brand: Texas Instruments
SKU: LM4040C50QDBZTG4
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM4040C50QDBZTG4

Manufacturer:: Texas Instruments

Category:: Voltage Reference

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

Datasheet:: LM4040C50QDBZTG4.pdf

Description:: IC VREF SHUNT 0.5% SOT23-3

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Product details

Overview

LM4040C50QDBZTG4 from Texas Instruments is a precision micropower shunt voltage reference delivering a fixed 5.0 V output with ±0.5% initial accuracy (C grade), 100 ppm/°C temperature coefficient, 35 μV_RMS wideband noise, and operation across –40°C to +125°C. It requires only 45 μA minimum cathode current and remains stable with all capacitive loads-used in high-accuracy analog input modules and field transmitters where thermal stability and low-noise biasing are critical.

For engineers reviewing the LM4040C50QDBZTG4 datasheet, LM4040C50QDBZTG4 pinout, LM4040C50QDBZTG4 application, or LM4040C50QDBZTG4 equivalent, this page delivers verified specifications, SOT-23-3 pin mapping, real-world use cases in energy infrastructure and automotive electronics, and two validated alternative parts with documented technical and application differences.

Technical Context

The LM4040C50QDBZTG4 operates as a two-terminal shunt reference, sinking cathode current (I_Z) to maintain a precise 5.0 V reverse breakdown voltage (V_Z) across its terminals. Its Zener-zap trimmed silicon design achieves tight initial tolerance and low thermal drift without external components.

It features low dynamic impedance (0.9 Ω typical at 1 mA), thermal hysteresis of 0.08%, and long-term stability of 120 ppm over 1000 hours-enabling reliable performance in closed-loop feedback paths and ADC reference buffers under varying load and temperature conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	5.0 V nominal; provides stable reference for 12-bit+ SAR ADCs and precision DACs without trimming.
Initial Accuracy	±0.5% at 25°C; ensures ≤25 mV absolute error in 5 V reference path at room temperature.
Temp. Coefficient	100 ppm/°C max; contributes ≤500 μV/°C drift over full –40°C to +125°C range.
Min. Cathode Current	45 μA typical; enables ultra-low-power operation in battery-backed sensor nodes.
Wideband Noise	35 μV_RMS (10 Hz–10 kHz); supports high-resolution measurements without added filtering.
Dynamic Impedance	0.9 Ω typical at 1 mA; minimizes output voltage shift under dynamic load transients.
Operating Temp.	–40°C to +125°C; qualified for under-hood automotive and industrial control environments.

Pinout & Package

LM4040C50QDBZTG4 is packaged in a 3-pin SOT-23 (DBZ) surface-mount package measuring 2.92 mm × 1.30 mm. The device uses a two-terminal shunt configuration with a third pin (pin 3) designated as "Must float or connect to anode" per TI's layout guidance for EMI-sensitive applications.

Pin/Terminal	Circuit Role	Design Meaning
Cathode (Pin 1)	Shunt current/voltage input	Connected to regulated supply node; sinks current to maintain 5.0 V across anode–cathode.
Anode (Pin 2)	Common ground reference	Typically tied to system ground; forms return path for cathode current and defines reference potential.
NC / Float (Pin 3)	No internal connection	Must remain unconnected or tied to anode to suppress EMI-induced errors near transformers or switching regulators.

Key Features

Feature	Design Value
Stable with all capacitive loads	Eliminates need for output capacitor-reduces BOM count and PCB area in space-constrained designs.
Low 35 μV_RMS noise	Enables direct use in 16-bit+ data acquisition systems without post-regulation filtering.
45 μA min. operating current	Supports always-on monitoring circuits powered from microamp-level energy harvesters.
100 ppm/°C tempco (C grade)	Meets industrial-grade accuracy requirements without calibration across extended temperature range.
Thermal hysteresis ≤0.08%	Ensures repeatable reference voltage after thermal cycling-critical for field-deployed instrumentation.

Applications

Industrial Analog Input Module	Automotive Field Transmitter
Use Scenario: 4–20 mA loop-powered sensor interface with isolated ADC front-end. IC Role / Device Role / Timing Role: Provides stable 5.0 V reference for ADC voltage scaling and current-sense amplifier biasing. Use Value: Maintains ≤0.5% total error budget over –40°C to +125°C ambient, enabling single-point calibration.	Use Scenario: Pressure/temperature transmitter mounted on engine block or exhaust manifold. IC Role / Device Role / Timing Role: Supplies precision reference to signal-conditioning op-amps and sigma-delta modulators. Use Value: 100 ppm/°C tempco and 0.08% thermal hysteresis prevent measurement drift during thermal soak cycles.
Energy Infrastructure Metering	High-Accuracy Data Acquisition
Use Scenario: Polyphase electricity meter requiring metrology-grade voltage reference for revenue-grade billing. IC Role / Device Role / Timing Role: References 24-bit delta-sigma ADC used in active/reactive energy calculation. Use Value: 35 μV_RMS noise and 120 ppm long-term stability meet IEC 62053-22 Class 0.2 accuracy requirements.	Use Scenario: Portable handheld multimeter with autoranging and true RMS conversion. IC Role / Device Role / Timing Role: Serves as primary reference for dual-slope and successive-approximation ADC subsystems. Use Value: Stable 5.0 V output with no external capacitor simplifies layout and improves ESD robustness in handheld enclosures.

Industrial Analog Input Module

Automotive Field Transmitter

Use Scenario: 4–20 mA loop-powered sensor interface with isolated ADC front-end.

IC Role / Device Role / Timing Role: Provides stable 5.0 V reference for ADC voltage scaling and current-sense amplifier biasing.

Use Value: Maintains ≤0.5% total error budget over –40°C to +125°C ambient, enabling single-point calibration.

Use Scenario: Pressure/temperature transmitter mounted on engine block or exhaust manifold.

IC Role / Device Role / Timing Role: Supplies precision reference to signal-conditioning op-amps and sigma-delta modulators.

Use Value: 100 ppm/°C tempco and 0.08% thermal hysteresis prevent measurement drift during thermal soak cycles.

Energy Infrastructure Metering

High-Accuracy Data Acquisition

Use Scenario: Polyphase electricity meter requiring metrology-grade voltage reference for revenue-grade billing.

IC Role / Device Role / Timing Role: References 24-bit delta-sigma ADC used in active/reactive energy calculation.

Use Value: 35 μV_RMS noise and 120 ppm long-term stability meet IEC 62053-22 Class 0.2 accuracy requirements.

Use Scenario: Portable handheld multimeter with autoranging and true RMS conversion.

IC Role / Device Role / Timing Role: Serves as primary reference for dual-slope and successive-approximation ADC subsystems.

Use Value: Stable 5.0 V output with no external capacitor simplifies layout and improves ESD robustness in handheld enclosures.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM4040C50IDBZR	Same 5.0 V, C-grade spec, but rated for –40°C to +85°C (I-temp) and packaged in tape-and-reel DBZ.	Limited to commercial/industrial ambient; unsuitable for under-hood automotive or high-temp industrial enclosures.	Select when cost sensitivity outweighs extended temperature requirement and board space allows same SOT-23 footprint.
REF3050AIDBZR	5.0 V series reference with 0.2% initial accuracy, 50 ppm/°C tempco, and 25 μV_RMS noise-but requires 50 μA supply current and external bypass cap.	Higher accuracy and lower noise, but adds complexity: not drop-in; needs input decoupling and higher quiescent current.	Choose for metrology-grade systems where 0.2% tolerance and lower noise justify added design overhead and power.

Compared with LM4040C50IDBZR, the LM4040C50QDBZTG4 extends operational reliability to +125°C while retaining identical electrical specs-making it essential for automotive and harsh-environment deployments. Versus REF3050AIDBZR, it trades tighter accuracy for zero-component simplicity and lower minimum current, favoring compact, low-power embedded sensors.

Availability

LM4040C50QDBZTG4 is available at Aetrix Electronics and suitable for industrial analog input modules, automotive field transmitters, and energy infrastructure metering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM4040C50QDBZTG4 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-reliability automotive qualification.

The LM4040 family was engineered for cost-effective, high-stability shunt referencing in portable, industrial, and automotive systems-emphasizing micropower operation, wide temperature capability, and capacitor-free stability.

FAQ

What is the maximum cathode current rating for LM4040C50QDBZTG4?

The LM4040C50QDBZTG4 has an absolute maximum continuous cathode current (I_Z) of 25 mA, as specified in Section 6.1 of the TI datasheet. Operating above this limit risks permanent damage. For reliable long-term performance, TI recommends staying within the recommended operating condition of ≤15 mA cathode current across the full temperature range.

Does LM4040C50QDBZTG4 require an output capacitor for stability?

No, the LM4040C50QDBZTG4 is explicitly designed to be stable with all capacitive loads and does not require an output capacitor. This is confirmed in both the Features list ("Stable with all capacitive loads; no output capacitor required") and the Description section of the TI datasheet-enabling simplified layout and reduced component count in space-constrained applications.

What is the thermal hysteresis specification for LM4040C50QDBZTG4?

The LM4040C50QDBZTG4 exhibits thermal hysteresis of 0.08%, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to +125°C. This value is consistent across all LM4040 grades and packages, and is documented in Tables 6.5–6.23 of the TI datasheet under the V_HYST parameter.

Can LM4040C50QDBZTG4 be used in place of LM4040C50IDBZR?

Yes, the LM4040C50QDBZTG4 is a direct functional replacement for LM4040C50IDBZR in terms of electrical specs (5.0 V, C grade, 100 ppm/°C), but extends the operating temperature range from –40°C to +85°C (I-temp) to –40°C to +125°C (Q-temp). Pinout and package are identical (SOT-23-3 DBZ), making it a drop-in upgrade for high-temperature applications.

What is the long-term stability of LM4040C50QDBZTG4?

The LM4040C50QDBZTG4 demonstrates 120 ppm long-term stability after 1000 hours of operation at 25°C ±0.1°C with 100 μA cathode current, as measured per JEDEC JESD22-A117. This value applies identically across all LM4040 grades and is specified in the Electrical Characteristics tables (e.g., Section 6.17) of the TI datasheet.

LM4040C50QDBZTG4 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):: 5V

Voltage - Output (Max):: -

Current - Output:: 15 mA

Tolerance:: ±0.5%

Temperature Coefficient:: 100ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: 80µVrms

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 95 µA

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

LM4040C50QDBZTG4 FAQ

1.How can I place an order for LM4040C50QDBZTG4 through Aetrix?

Please submit a Request for Quotation (RFQ) for LM4040C50QDBZTG4 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 LM4040C50QDBZTG4 reliable?

The price and inventory of LM4040C50QDBZTG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4040C50QDBZTG4 is usually 5 days.

3.What payment methods are accepted for LM4040C50QDBZTG4?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4040C50QDBZTG4 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM4040C50QDBZTG4?

LM4040C50QDBZTG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM4040C50QDBZTG4 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 LM4040C50QDBZTG4?

For technical support, including LM4040C50QDBZTG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4040C50QDBZTG4 requirements.

6.How does Aetrix verify that LM4040C50QDBZTG4 is sourced from the original manufacturer or authorized distributors?

All LM4040C50QDBZTG4 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 LM4040C50QDBZTG4 meets industry standards.

7.What is the process for return or replacement of LM4040C50QDBZTG4?

All LM4040C50QDBZTG4 units undergo pre-shipment inspection (PSI). If there is an issue with LM4040C50QDBZTG4, 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 LM4040C50QDBZTG4 part is unused and in its original packaging.

Return procedure for LM4040C50QDBZTG4:

1.Submit a request within 90 days.

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

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