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

Diodes Incorporated LM4040B50FTA

Name: LM4040B50FTA
Brand: Diodes Incorporated
SKU: LM4040B50FTA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM4040B50FTA

Manufacturer:: Diodes Incorporated

Category:: Voltage Reference

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

Datasheet:: LM4040B50FTA.pdf

Description:: IC VREF SHUNT 0.2% SOT23

Quantity:: RFQ Add To RFQ list

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Inventory:8,285

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Product details

Overview

LM4040B50FTA from Diodes Incorporated is a precision 5.0 V shunt voltage reference in SOT23 package, featuring ±0.2% initial tolerance at +25°C, 30 ppm/°C max temperature coefficient over –40°C to +125°C, and stable operation from 60 µA to 15 mA reverse current. It delivers low 80 µV_RMS noise (10 Hz–10 kHz) and requires no output capacitor, making it ideal for space-constrained, battery-powered precision analog circuits.

For engineers reviewing the LM4040B50FTA datasheet, LM4040B50FTA pinout, LM4040B50FTA application, or LM4040B50FTA equivalent, key selection criteria include reverse breakdown voltage stability across load current variation, thermal hysteresis (<0.08%), long-term drift (120 ppm over 1000 hrs), and compatibility with capacitive loads in portable instrumentation and data acquisition systems.

Technical Context

The LM4040B50FTA operates as a two-terminal shunt reference, regulating voltage by sinking adjustable reverse current while maintaining a precise 5.0 V nominal breakdown. Its bandgap core achieves tight initial tolerance and low tempco without external compensation.

It exhibits minimal dynamic impedance (1.1 Ω at 1 mA, 120 Hz) and maintains stability with up to 1 µF tantalum capacitance on the cathode. Pin 3 (die attach) must be left floating or tied to pin 2 per layout guidance to avoid parasitic conduction paths.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	5.0 V nominal reverse breakdown voltage at 100 µA, enabling accurate 5 V system biasing
Initial Tolerance	±0.2% at +25°C, supporting high-accuracy ADC/DAC reference and calibration circuits
Tempco (max)	30 ppm/°C over –40°C to +125°C, ensuring <±1.5 mV drift across full industrial range
Operating Current	60 µA to 15 mA reverse current range, allowing use in ultra-low-power and high-current regulation
Noise (10 Hz–10 kHz)	80 µV_RMS, minimizing added error in precision measurement front-ends
Dynamic Impedance	1.1 Ω at 1 mA, 120 Hz, providing stable regulation under fast load transients
Thermal Hysteresis	0.08% over –40°C to +125°C cycling, preserving repeatability in thermally varying environments

Pinout & Package

SOT23-3 package: 3-pin surface-mount outline with die attached to pin 3; pin 3 must be left floating or connected to pin 2 per manufacturer layout requirement.

Pin/Terminal	Circuit Role	Design Meaning
Anode (Pin 1)	Reference ground node	Common return path for reverse current; ties to system GND in shunt configuration
Cathode (Pin 2)	Regulated output node	Provides stable 5.0 V reference; connects to series resistor and load
NC / Die Attach (Pin 3)	Internal die connection	Must float or tie to pin 2; not electrically isolated - critical for thermal and electrical integrity

Key Features

Feature	Design Value
No output capacitor required	Stable operation with 0–1 µF cathode capacitance eliminates BOM cost and board area for decoupling
Low operating current floor	60 µA minimum reverse current enables use in sub-100 µA battery monitoring circuits
High current capability	15 mA max reverse current supports active regulation in higher-power analog subsystems
Green, RoHS-compliant packaging	Lead-free, halogen- and antimony-free SOT23 meets EU Directive 2015/863/EU requirements
Extended temperature operation	–40°C to +125°C ambient range qualifies for industrial and automotive under-hood applications

Applications

Battery-Powered Instrumentation

Precision Data Acquisition

Use Scenario: Portable multimeter measuring 0–5 V DC signals with 16-bit resolution.

IC Role / Device Role / Timing Role: Shunt reference providing stable 5.0 V reference for SAR ADC and internal DAC calibration.

Use Value: ±0.2% initial tolerance and 30 ppm/°C tempco ensure <±0.5 LSB error over temperature, meeting Class II accuracy standards.

Use Scenario: Industrial sensor node digitizing thermocouple and RTD outputs via 24-bit sigma-delta ADC.

IC Role / Device Role / Timing Role: Primary voltage reference for ADC reference input and excitation current source feedback.

Use Value: 80 µV_RMS noise and 1.1 Ω dynamic impedance prevent reference-induced quantization noise and gain drift.

Portable Communications

Notebook Power Management

Use Scenario: LTE modem module requiring stable 5 V bias for RF front-end LNA and mixer stages.

IC Role / Device Role / Timing Role: Low-noise shunt reference supplying clean bias to analog signal chain components.

Use Value: No-output-capacitor operation simplifies layout in dense RF sections; 60 µA min current extends standby battery life.

Use Scenario: Notebook motherboard sensing 5 V rail for adaptive power sequencing and OVP/OCP protection.

IC Role / Device Role / Timing Role: Precision voltage monitor reference for comparator-based fault detection circuitry.

Use Value: 0.08% thermal hysteresis ensures repeatable trip thresholds after thermal cycling during sleep/wake cycles.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TL4050B50QDBZR	±0.2% tolerance, 50 ppm/°C max tempco, 75 µA min current, SOIC-5 package	Larger footprint; requires external capacitor for stability at >100 nF	Preferred when SOIC handling or higher current drive (>20 mA) is needed
REF3050AIDBZR	±0.2% tolerance, 50 ppm/°C max tempco, 50 µA min current, SOT23-3 package	Series reference architecture; requires input voltage ≥5.2 V and external bypass cap	Chosen when supply headroom allows series topology and lower quiescent current is critical

Compared with TL4050B50QDBZR and REF3050AIDBZR, the LM4040B50FTA offers superior thermal stability (30 vs. 50 ppm/°C), lower noise (80 vs. 95 µV_RMS), and true capacitor-free operation - making it optimal for compact, low-drift, battery-sensitive designs where shunt topology is acceptable.

Availability

LM4040B50FTA is available at Aetrix Electronics and suitable for battery-powered instrumentation, precision data acquisition, and portable communications equipment requiring stable component supply with guaranteed long-term continuity.

Supply support for LM4040B50FTA 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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal ICs, with emphasis on high-reliability, energy-efficient solutions for industrial, computing, and consumer markets.

The LM4040 family is designed for precision voltage referencing in space-constrained, low-power systems - delivering micro-power operation, tight tolerances, and robust thermal performance without external components.

FAQ

What is the minimum reverse current required for LM4040B50FTA to maintain regulation?

The LM4040B50FTA requires a minimum reverse current of 60 µA at +25°C to achieve specified voltage accuracy and stability. At –40°C to +125°C, this increases to 83 µA. Below this threshold, the device exits regulation and output voltage drops nonlinearly.

Can LM4040B50FTA drive a 1 µF tantalum capacitor directly on its cathode?

Yes - the LM4040B50FTA is explicitly characterized for stable operation with up to 1 µF tantalum capacitance on the cathode, eliminating need for series resistance or isolation. This is confirmed in Diodes' DS33195 Rev. 8, Figure 7 (Reference Impedance).

How does pin 3 (SOT23) affect PCB layout for LM4040B50FTA?

Pin 3 is internally connected to the silicon die and must be left floating or tied to pin 2 (cathode); connecting it to ground or other potentials creates unintended conduction paths and degrades regulation accuracy and thermal performance per datasheet Section 12.

Is LM4040B50FTA qualified for automotive applications?

No - LM4040B50FTA is an industrial-grade part. For automotive use, Diodes offers the LM4040Q series (e.g., LM4040QB50QDBZR), which is AEC-Q100 Grade 1 qualified (–40°C to +125°C) and manufactured in IATF 16949-certified facilities.

LM4040B50FTA Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

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

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Reference Type:: Shunt

Output Type:: Fixed

Voltage - Output (Min/Fixed):: 5V

Voltage - Output (Max):: -

Current - Output:: 15 mA

Tolerance:: ±0.2%

Temperature Coefficient:: 100ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: 80µVrms

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 83 µA

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

LM4040B50FTA FAQ

1.How can I place an order for LM4040B50FTA through Aetrix?

Please submit a Request for Quotation (RFQ) for LM4040B50FTA 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 LM4040B50FTA reliable?

The price and inventory of LM4040B50FTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4040B50FTA is usually 5 days.

3.What payment methods are accepted for LM4040B50FTA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4040B50FTA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM4040B50FTA?

LM4040B50FTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM4040B50FTA 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 LM4040B50FTA?

For technical support, including LM4040B50FTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4040B50FTA requirements.

6.How does Aetrix verify that LM4040B50FTA is sourced from the original manufacturer or authorized distributors?

All LM4040B50FTA 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 LM4040B50FTA meets industry standards.

7.What is the process for return or replacement of LM4040B50FTA?

All LM4040B50FTA units undergo pre-shipment inspection (PSI). If there is an issue with LM4040B50FTA, 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 LM4040B50FTA part is unused and in its original packaging.

Return procedure for LM4040B50FTA:

1.Submit a request within 90 days.

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

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