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

STMicroelectronics LM4040CELT-2.5

Name: LM4040CELT-2.5
Brand: STMicroelectronics
SKU: LM4040CELT-2.5
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM4040CELT-2.5

Manufacturer:: STMicroelectronics

Category:: Voltage Reference

Package:: SC-70, SOT-323

Datasheet:: LM4040CELT-2.5.pdf

Description:: IC VREF SHUNT 2.5V SC70

Quantity:: RFQ Add To RFQ list

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Inventory:1,279

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Product details

Overview

LM4040CELT-2.5 from STMicroelectronics is a precision micropower shunt voltage reference delivering a stable 2.5 V output with ±0.5% initial accuracy at 25 °C, 70 ppm/°C max temperature coefficient, and ultra-low 10 µA operating current. It operates across -40 to +125 °C and is optimized for space-constrained, battery-powered data acquisition systems requiring high DC stability.

For engineers reviewing the LM4040CELT-2.5 datasheet, LM4040CELT-2.5 pinout, LM4040CELT-2.5 application, or LM4040CELT-2.5 equivalent, key selection criteria include its 2.5 V fixed reference voltage, SOT23-3L package footprint, low-frequency noise (10 µV_p-p), and compatibility with capacitive loads up to 1 µF without instability.

Technical Context

The LM4040CELT-2.5 functions as a two-terminal shunt reference, regulating voltage by sinking adjustable current through its cathode-anode path. Its bandgap-based core achieves ±0.5% tolerance at 25 °C and maintains 70 ppm/°C tempco over full industrial range, with dynamic impedance under 0.3 Ω across 10 µA–10 mA.

It exhibits very low 10 µV_p-p low-frequency noise (0.1–10 Hz) and remains stable with capacitive loads up to 1 µF-enabling direct use in ADC reference buffers and portable sensor signal chains without external compensation.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	2.5 V ±0.5% at 25 °C - ensures accurate 12-bit+ ADC reference without calibration.
Operating Current	10 µA typical - enables multi-year operation in coin-cell–powered IoT sensors.
Tempco	≤70 ppm/°C - limits drift to ±0.875 mV over -40 to +125 °C ambient.
Low-Freq Noise	10 µV_p-p (0.1–10 Hz) - preserves resolution in precision instrumentation front-ends.
Dynamic Impedance	0.15–0.3 Ω - minimizes load-induced voltage shift in varying-current applications.
Capacitive Load Stability	Stable up to 1 µF - allows direct decoupling without series resistance or isolation.
Max Junction Temp	+150 °C - supports operation in sealed industrial enclosures with limited airflow.

Pinout & Package

LM4040CELT-2.5 uses the SOT23-3L surface-mount package (2.9 mm × 2.6 mm × 1.1 mm), optimized for high-density PCB layouts. The device has three terminals: Cathode (pin 1), Anode (pin 3), and NC (pin 2), where NC must remain unconnected or tied to anode per datasheet guidance.

Pin/Terminal	Circuit Role	Design Meaning
Cathode (Pin 1)	Reference output node	Sinks regulated current; connects to ADC REF+ or op-amp inverting input.
Anode (Pin 3)	Ground reference terminal	Must be connected to system ground; defines 2.5 V potential relative to this node.
NC (Pin 2)	No-connect terminal	Internally unused; leave floating or tie to anode-no electrical function.

Key Features

Feature	Design Value
Fixed 2.5 V output	Eliminates external resistor divider, reducing BOM count and layout area in compact designs.
±0.5% initial accuracy	Supports uncalibrated 12-bit SAR ADCs without trimming, lowering production test time.
10 µA min operating current	Enables use with high-value bias resistors (>1 MΩ), extending battery life in wake-on-event systems.
Stable with 1 µF capacitive load	Permits local ceramic decoupling at point-of-load, improving PSRR in noisy power domains.
Industrial temperature range	Validated operation from -40 to +125 °C enables deployment in automotive cabin modules and motor control enclosures.

Applications

Portable Medical Sensors

Data Acquisition Modules

Use Scenario: Wearable ECG patch measuring microvolt-level biopotentials with 3.3 V MCU and 16-bit sigma-delta ADC.

IC Role / Device Role / Timing Role: Shunt reference providing stable 2.5 V reference for ADC and analog front-end gain stages.

Use Value: 10 µV_p-p low-frequency noise prevents baseline wander; 10 µA quiescent current extends CR2032 battery life beyond 18 months.

Use Scenario: Industrial 4–20 mA loop-powered transmitter with HART modulation and local sensor interface.

IC Role / Device Role / Timing Role: Precision voltage reference for DAC output scaling and sensor excitation circuitry.

Use Value: ±0.5% accuracy and 70 ppm/°C tempco ensure <0.1% total error across ambient temperature swings in field installations.

Smart Metering ICs

Automotive Cabin Control Units

Use Scenario: Electricity meter SoC performing metrology-grade voltage/current sampling using dual 24-bit ADCs.

IC Role / Device Role / Timing Role: Primary reference source for both ADCs and internal LDO feedback networks.

Use Value: Dynamic impedance <0.3 Ω prevents cross-talk between ADC channels during simultaneous sampling events.

Use Scenario: HVAC control module in vehicle dashboard with thermistor, humidity, and CO₂ sensing.

IC Role / Device Role / Timing Role: Stable reference for ratiometric sensor conditioning and microcontroller ADC calibration.

Use Value: Operation up to +125 °C ambient and stability with 1 µF ceramic cap enable direct placement near heat-generating power regulators.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLVH431ACDBVR	Adjustable (2.5–36 V) vs. fixed 2.5 V; higher 80 µA I_Q; ±0.5% accuracy only at 25 °C.	Requires external resistor network; less suitable for ultra-low-power or space-constrained designs.	Choose when programmability or higher voltage output is required; avoid if minimizing component count is critical.
MAX6008AEUR+T	Fixed 2.5 V, SOT23-3, but ±0.2% accuracy and 15 µA I_Q; no guaranteed 1 µF capacitive load stability.	Better initial accuracy but higher current draw and narrower stability margin limits use in high-noise environments.	Prefer for highest-accuracy applications where 5 µA extra current is acceptable and load capacitance is <100 nF.

Compared with TLVH431ACDBVR and MAX6008AEUR+T, LM4040CELT-2.5 uniquely balances ultra-low 10 µA operation, guaranteed 1 µF capacitive stability, and SOT23-3L footprint-making it optimal for battery-powered, space-limited, and noise-sensitive measurement systems.

Availability

LM4040CELT-2.5 is available at Aetrix Electronics and suitable for portable medical sensors, industrial data acquisition modules, smart metering ICs, and automotive cabin control units requiring stable component supply and long-term lifecycle support.

Supply support for LM4040CELT-2.5 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The LM4040 series belongs to ST's precision analog portfolio, engineered specifically for high-accuracy, low-power shunt reference applications in harsh thermal environments and miniaturized systems.

FAQ

What is the minimum operating current for LM4040CELT-2.5 at 25 °C?

The minimum operating current (I_kmin) is 10 µA at 25 °C for the 2.5 V version, as specified in Table 3 of DS13886 Rev 4. Below this current, regulation is not guaranteed; design must ensure bias network delivers ≥10 µA across all temperature and load conditions.

Can LM4040CELT-2.5 drive a 1 µF ceramic capacitor directly?

Yes-Figure 11 (Stability plane vs. C_OUT) in DS13886 Rev 4 confirms stable operation with up to 1 µF capacitive load at operating currents from 10 µA to 15 mA. No series resistor or isolation is required, simplifying layout for ADC reference bypassing.

Is pin 2 (NC) on the SOT23-3L package electrically connected internally?

No-pin 2 is a true no-connect terminal with no internal bond wire or silicon connection. Per Figure 1 and datasheet note, it must be left unconnected or tied to the anode (pin 3); floating NC does not affect performance or reliability.

How does the 70 ppm/°C temperature coefficient translate to voltage drift over temperature?

Over the full -40 to +125 °C range (165 °C span), maximum drift is 70 ppm/°C × 165 °C × 2.5 V = ±28.875 mV. This yields a worst-case output range of 2.471125 V to 2.528875 V, meeting requirements for 12-bit accuracy (±1.22 mV LSB at 2.5 V).

LM4040CELT-2.5 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: SC-70, SOT-323

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Reference Type:: Shunt

Output Type:: Fixed

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: -

Current - Output:: 15 mA

Tolerance:: ±0.5%

Temperature Coefficient:: 70ppm/°C

Noise - 0.1Hz to 10Hz:: 10µVp-p

Noise - 10Hz to 10kHz:: 95µVrms

Voltage - Input:: -

Current - Supply:: -

Current - Cathode:: 12 mA

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-323-3

LM4040CELT-2.5 FAQ

1.How can I place an order for LM4040CELT-2.5 through Aetrix?

Please submit a Request for Quotation (RFQ) for LM4040CELT-2.5 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 LM4040CELT-2.5 reliable?

The price and inventory of LM4040CELT-2.5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4040CELT-2.5 is usually 5 days.

3.What payment methods are accepted for LM4040CELT-2.5?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4040CELT-2.5 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM4040CELT-2.5?

LM4040CELT-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM4040CELT-2.5 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 LM4040CELT-2.5?

For technical support, including LM4040CELT-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4040CELT-2.5 requirements.

6.How does Aetrix verify that LM4040CELT-2.5 is sourced from the original manufacturer or authorized distributors?

All LM4040CELT-2.5 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 LM4040CELT-2.5 meets industry standards.

7.What is the process for return or replacement of LM4040CELT-2.5?

All LM4040CELT-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM4040CELT-2.5, 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 LM4040CELT-2.5 part is unused and in its original packaging.

Return procedure for LM4040CELT-2.5:

1.Submit a request within 90 days.

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

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