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

Diodes Incorporated LM4040B33FTA

Name: LM4040B33FTA
Brand: Diodes Incorporated
SKU: LM4040B33FTA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM4040B33FTA

Manufacturer:: Diodes Incorporated

Category:: Voltage Reference

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

Datasheet:: LM4040B33FTA.pdf

Description:: IC VREF SHUNT 0.2% SOT23

Quantity:: RFQ Add To RFQ list

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Inventory:3,238

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Product details

Overview

LM4040B33FTA from Diodes Incorporated is a precision 3.3V shunt voltage reference in SOT23 package, rated for ±0.2% initial tolerance at +25°C, 20ppm/°C max temperature coefficient over –40°C to +125°C, and stable operation from 60µA to 15mA reverse current - used as a compact, low-noise reference in portable power monitoring circuits.

For engineers reviewing the LM4040B33FTA datasheet, LM4040B33FTA pinout, LM4040B33FTA application, or LM4040B33FTA equivalent, key selection criteria include reverse breakdown voltage accuracy, thermal stability across industrial temperature range, capacitive load immunity, and SOT23 footprint compatibility with space-constrained PCB layouts.

Technical Context

The LM4040B33FTA operates as a two-terminal bandgap-based shunt reference, requiring only an external series resistor to regulate output voltage. Its internal architecture delivers stable 3.3V reverse breakdown with minimal dependence on operating current across 60µA–15mA.

It maintains <0.08% thermal hysteresis over –40°C to +125°C and exhibits 35µVRMS noise (10Hz–10kHz) at 100µA bias. No output capacitor is required due to inherent stability with capacitive loads up to 1µF tantalum.

Key Specifications

Parameter	Value and Actual Design Meaning
Reference Voltage	3.3V nominal reverse breakdown voltage at 100µA, enabling precise 3.3V rail monitoring or ADC reference scaling.
Initial Tolerance	±0.2% at +25°C (B-grade), ensuring ≤±6.6mV absolute error in factory-calibrated systems without trimming.
Temp Coefficient	±20ppm/°C typical (–40°C to +125°C), limiting drift to ≤±66ppm over full range - critical for battery-powered instrumentation.
Operating Current	60µA to 15mA reverse bias range, supporting ultra-low-power sleep modes and high-accuracy active regulation in same device.
Noise (10Hz–10kHz)	35µVRMS at 100µA, minimizing voltage reference contribution to system noise floor in precision data acquisition.
Dynamic Impedance	0.4Ω at 1mA/120Hz, ensuring minimal output perturbation during transient load changes in feedback loops.
Long-Term Stability	120ppm after 1000 hours, guaranteeing predictable aging behavior in field-deployed industrial sensors.

Pinout & Package

SOT23-3 package with die attached to pin 3; pin 3 must be left floating or connected to pin 2 per layout guidelines. Pin 2 must be left floating or connected to pin 1. No SC70-5 variant is active - only SOT23 is in full production.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Anode)	Current sink terminal	Connected to system ground; defines reference return path and sets cathode-to-ground voltage.
Pin 2 (Cathode)	Output/reference terminal	Provides regulated 3.3V relative to pin 1; connects to feedback node or ADC reference input.
Pin 3 (NC / Die Attach)	Internal die connection	Must float or tie to pin 2; electrically coupled to die substrate - improper handling causes calibration shift.

Key Features

Feature	Design Value
No external capacitor required	Stable with up to 1µF tantalum load capacitance - eliminates BOM cost and board area for decoupling caps.
Micro-power operation	60µA minimum operating current enables use in coin-cell-powered devices with multi-year battery life.
Wide temperature range	–40°C to +125°C operation supports deployment in automotive engine compartments and industrial PLCs.
Low noise performance	35µVRMS (10Hz–10kHz) ensures minimal quantization error when used as ADC reference in 16-bit+ systems.
Green packaging	Lead-free, halogen-free, antimony-free SOT23 meets RoHS 3 and automotive environmental compliance standards.

Applications

Battery-Powered Equipment

Precision Power Supplies

Use Scenario: Monitoring Li-ion cell voltage in wireless sensor nodes with 10-year battery target.

IC Role / Device Role / Timing Role: Shunt reference providing stable 3.3V reference for ADC measurement of battery voltage under varying load and temperature.

Use Value: ±0.2% tolerance and 20ppm/°C TC ensure <±10mV total error across –20°C to +60°C ambient, enabling accurate state-of-charge estimation.

Use Scenario: Feedback reference in isolated DC-DC converter for medical diagnostic equipment.

IC Role / Device Role / Timing Role: Precision voltage reference in secondary-side optocoupler feedback loop to regulate 3.3V output rail.

Use Value: Low dynamic impedance (0.4Ω) minimizes regulation error during load transients, maintaining <±0.5% output stability.

Portable Instrumentation

Data Acquisition Systems

Use Scenario: Handheld multimeter with 4½-digit resolution requiring stable internal reference.

IC Role / Device Role / Timing Role: Primary reference source for dual-slope ADC and auto-zero circuitry.

Use Value: 35µVRMS noise and <0.08% thermal hysteresis prevent drift-induced offset errors during repeated measurements across temperature cycles.

Use Scenario: Modular DAQ module for industrial process control with 16-bit SAR ADC.

IC Role / Device Role / Timing Role: External reference for ADC to replace internal bandgap and improve INL/DNL performance.

Use Value: 120ppm long-term stability ensures calibration validity over 12 months, reducing field recalibration frequency.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLV431ACDBVR	2.5V adjustable reference (1.24V–6V), ±0.5% tolerance, higher 300µA min current, 0.3Ω Z_OUT	Requires external resistors for 3.3V setting; less suitable for ultra-low-power designs due to higher I_MIN	Choose when programmability or tighter Z_OUT at >1mA is prioritized over micro-power operation.
MAX6033AESA+	3.3V fixed, ±0.1% tolerance, 10ppm/°C TC, but SOT23-5 package with enable pin and higher 65µA I_MIN	Includes shutdown mode; incompatible pinout with LM4040B33FTA's 3-pin SOT23 layout	Choose when sub-0.1% accuracy and lower TC are mandatory, and board redesign for 5-pin package is acceptable.

Compared with TLV431ACDBVR and MAX6033AESA+, the LM4040B33FTA offers superior micro-power capability (60µA I_MIN) and true 3-pin SOT23 drop-in compatibility, making it optimal for legacy-replacement and space-constrained designs where fixed 3.3V and minimal bill-of-materials are critical.

Availability

LM4040B33FTA is available at Aetrix Electronics and suitable for battery-powered equipment, precision power supplies, and portable instrumentation requiring stable component supply with guaranteed long-term sourcing.

Supply support for LM4040B33FTA 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 solutions, with emphasis on reliability, efficiency, and green manufacturing.

The LM4040 series belongs to Diodes' precision analog portfolio, designed specifically for high-accuracy, low-power voltage referencing in portable, industrial, and automotive-qualified systems.

FAQ

What is the minimum operating current for LM4040B33FTA at –40°C?

The minimum operating current is 70µA at –40°C to +125°C per Electrical Characteristics table. Below this, the device may not maintain specified 3.3V breakdown voltage or temperature coefficient, risking reference inaccuracy in cold-temperature deployments such as outdoor IoT sensors.

Can LM4040B33FTA drive a 100pF capacitive load without oscillation?

Yes - the LM4040B33FTA is explicitly characterized for stability with capacitive loads up to 1µF tantalum, so 100pF presents no risk of oscillation. This eliminates need for series resistance or isolation buffers in most PCB routing scenarios.

Is pin 3 of the SOT23 package electrically connected internally?

Yes - pin 3 is bonded to the silicon die substrate and forms part of the thermal path. Per datasheet guidance, it must be left floating or tied to pin 2 (cathode); connecting it to ground or other potentials violates internal biasing and degrades voltage accuracy.

How does long-term stability impact calibration intervals in test equipment?

With 120ppm drift after 1000 hours, LM4040B33FTA contributes ≤0.012% reference error over one year of continuous operation - enabling annual calibration cycles in benchtop DMMs and reducing maintenance overhead versus references with >500ppm/year drift.

LM4040B33FTA 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):: 3.3V

Voltage - Output (Max):: -

Current - Output:: 15 mA

Tolerance:: ±0.2%

Temperature Coefficient:: 100ppm/°C

Noise - 0.1Hz to 10Hz:: -

Noise - 10Hz to 10kHz:: 35µVrms

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 70 µA

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

LM4040B33FTA FAQ

1.How can I place an order for LM4040B33FTA through Aetrix?

Please submit a Request for Quotation (RFQ) for LM4040B33FTA 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 LM4040B33FTA reliable?

The price and inventory of LM4040B33FTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4040B33FTA is usually 5 days.

3.What payment methods are accepted for LM4040B33FTA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4040B33FTA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM4040B33FTA?

LM4040B33FTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM4040B33FTA 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 LM4040B33FTA?

For technical support, including LM4040B33FTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4040B33FTA requirements.

6.How does Aetrix verify that LM4040B33FTA is sourced from the original manufacturer or authorized distributors?

All LM4040B33FTA 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 LM4040B33FTA meets industry standards.

7.What is the process for return or replacement of LM4040B33FTA?

All LM4040B33FTA units undergo pre-shipment inspection (PSI). If there is an issue with LM4040B33FTA, 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 LM4040B33FTA part is unused and in its original packaging.

Return procedure for LM4040B33FTA:

1.Submit a request within 90 days.

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

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