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Texas Instruments LM4128BMFX-2.5
- Part No.:
- LM4128BMFX-2.5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM4128BMFX-2.5.pdf
- Description:
- IC VREF SERIES 0.2% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,329
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Product details
Overview
LM4128BMFX-2.5 from National Semiconductor is a precision micropower series voltage reference in SOT-23-5 package, delivering 2.5 V output with ±0.2% initial accuracy, 75 ppm/°C temperature coefficient, and 60 µA quiescent current. It features an enable pin for 3 µA shutdown mode, supports up to 20 mA load current, and operates across −40°C to +125°C - ideal for battery-powered instrumentation and portable data acquisition systems.
For engineers reviewing the LM4128BMFX-2.5 datasheet, LM4128BMFX-2.5 pinout, LM4128BMFX-2.5 application, or LM4128BMFX-2.5 equivalent, key selection considerations include dropout voltage (≤400 mV at 10 mA), line regulation (50 ppm/V), load regulation (25–120 ppm/mA), output noise (275 µVPP, 0.1–10 Hz), and thermal hysteresis (75 ppm).
Technical Context
The LM4128BMFX-2.5 uses a band-gap–derived reference core optimized for low-power, high-stability operation in space-constrained designs. Its series architecture eliminates need for external stabilization capacitors while maintaining stability with capacitive loads up to 10 µF.
It integrates an enable input (EN) that controls internal biasing to achieve 3 µA shutdown current, and accepts input voltages from (VREF + 400 mV) to 5.5 V. The device exhibits indefinite short-circuit protection (75 mA limit) and achieves typical turn-on time of 33.2 µs into 1 µF load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.5 V nominal; enables precise ADC/DAC biasing and sensor excitation at standard reference level. |
| Initial Accuracy | ±0.2% at 25°C (B grade); ensures ≤5 mV absolute error without calibration in production systems. |
| Tempco | 75 ppm/°C max; limits drift to ≤23.4 µV/°C over −40°C to +125°C operating range. |
| Quiescent Current | 60 µA typical; supports multi-year battery life in always-on portable monitoring devices. |
| Dropout Voltage | 400 mV max at 10 mA load; allows operation from 2.9 V supply in 3.3 V rail-constrained systems. |
| Shutdown Current | 3 µA typical with EN = 0 V; reduces standby power by >95% versus active mode. |
| Output Noise | 275 µVPP (0.1–10 Hz); meets 16-bit ADC reference noise floor requirements (e.g., <0.5 LSB for 2.5 V full-scale). |
Pinout & Package
SOT-23-5 package (NS MF05A), surface-mount, 1.6 mm × 2.9 mm footprint with 0.95 mm height - optimized for high-density PCB layouts in portable electronics.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | N/C | No-connect pin; must remain unconnected and floating per datasheet specification. |
| 2 | GND | Analog ground reference; requires low-impedance connection to system AGND plane. |
| 3 | EN | Active-high enable input; pulls up internally (~2 µA); drives high (>65% VIN) to activate reference output. |
| 4 | VIN | Input supply pin; accepts 2.9 V to 5.5 V; must be bypassed with ≥0.1 µF ceramic capacitor (X5R/X7R). |
| 5 | VREF | Precision 2.5 V output; capable of sourcing up to 20 mA; stable with up to 10 µF capacitive load. |
Key Features
| Feature | Design Value |
|---|---|
| Enable-controlled shutdown | Reduces supply current from 60 µA to 3 µA - critical for duty-cycled sensor nodes and IoT edge devices. |
| Capacitor-free stability | Eliminates mandatory output capacitor; simplifies layout and reduces BOM count in space-limited applications. |
| Low ESR ceramic compatibility | Stable with X5R/X7R MLCCs; avoids instability risks associated with tantalum or aluminum electrolytics. |
| Indefinite short-circuit protection | Self-limits output current to 75 mA during fault; prevents thermal runaway and enables robust field deployment. |
| Wide temperature operation | Specified from −40°C to +125°C junction; supports automotive under-hood and industrial control environments. |
Applications
| Portable Data Acquisition | Automotive Sensor Conditioning |
|---|---|
Use Scenario: Handheld multimeter or battery-powered environmental logger sampling analog sensors at 1–10 kSPS. IC Role / Device Role / Timing Role: Precision 2.5 V reference for 16-bit SAR ADC front-end, ensuring consistent full-scale definition across temperature and battery discharge. Use Value: ±0.2% initial accuracy and 75 ppm/°C tempco maintain <0.008% total error over −20°C to +70°C ambient - enabling single-point calibration. |
Use Scenario: Engine coolant temperature or exhaust gas oxygen sensor signal conditioning module in Tier-1 automotive subsystem. IC Role / Device Role / Timing Role: Stable excitation source for ratiometric bridge sensors and reference for analog front-end amplifiers. Use Value: AEC-Q100 Grade 1 qualification (BQ variant available) and −40°C to +125°C operation ensure reliability in harsh under-hood environments. |
| Medical Vital Sign Monitor | Industrial Process Controller |
Use Scenario: Portable ECG or pulse oximeter requiring low-noise, low-power analog signal chain for FDA-cleared Class II devices. IC Role / Device Role / Timing Role: Low-noise (275 µVPP) 2.5 V reference for precision instrumentation amplifier gain-setting and ADC reference. Use Value: 60 µA quiescent current extends single-charge battery life beyond 72 hours; shutdown mode further extends standby duration. |
Use Scenario: DIN-rail mounted PLC analog I/O module converting 4–20 mA loop signals with 0.1% system accuracy requirement. IC Role / Device Role / Timing Role: Primary voltage reference for 24-bit ΣΔ ADC and DAC feedback path in isolated analog output stage. Use Value: Load regulation (25 ppm/mA) and line regulation (50 ppm/V) minimize gain error across varying loop supply and load conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| REF3025AIDBZR | 2.5 V, ±0.2% initial accuracy, 50 ppm/°C, 50 µA IQ, SOT-23-3 (no EN pin) | No enable function; fixed output only; smaller 3-pin footprint but lacks shutdown control | Select when board space is tighter and shutdown is managed externally or unnecessary. |
| ADR3425ARTZ-R7 | 2.5 V, ±0.1% initial accuracy, 10 ppm/°C, 120 µA IQ, SOT-23-5 (with EN) | Higher precision and lower tempco, but 2× higher supply current and higher cost | Select when ultra-low drift (<10 ppm/°C) is required for metrology-grade systems, accepting higher power budget. |
Compared with REF3025AIDBZR, LM4128BMFX-2.5 adds enable control and better load regulation; compared with ADR3425ARTZ-R7, it trades tempco and accuracy for 50% lower quiescent current and lower unit cost - making it optimal for mid-precision, battery-sensitive applications.
Availability
LM4128BMFX-2.5 is available at Aetrix Electronics and suitable for portable instrumentation, automotive sensor modules, and industrial process controllers requiring stable component supply with guaranteed long-term availability.
Supply support for LM4128BMFX-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
National Semiconductor was a U.S.-based analog semiconductor company acquired by Texas Instruments in 2011; its precision reference portfolio remains widely deployed in industrial and automotive systems.
The LM4128 family was designed for micropower, high-accuracy voltage referencing in space-constrained, battery-operated equipment - emphasizing low dropout, enable control, and robust capacitive-load stability.
FAQ
What is the maximum input voltage for LM4128BMFX-2.5?
The LM4128BMFX-2.5 supports a maximum input voltage of 5.5 V. Operation above this level risks permanent damage per Absolute Maximum Ratings. For reliable performance, VIN must also exceed VREF + 400 mV (i.e., ≥2.9 V) at 10 mA load, as specified in the Operating Ratings section of the datasheet.
Does LM4128BMFX-2.5 require an external output capacitor?
No, LM4128BMFX-2.5 is stable without an external output capacitor and is certified for use with capacitive loads up to 10 µF. An output capacitor is optional and recommended only to improve load transient response - especially when switching between light and heavy loads - but not required for basic regulation stability.
What is the shutdown current of LM4128BMFX-2.5?
The shutdown current of LM4128BMFX-2.5 is 3 µA typical (max 7 µA) when the EN pin is driven low (≤35% of VIN). This ultra-low standby current enables extended battery life in intermittently active systems such as wireless sensor nodes and portable diagnostic tools.
Can LM4128BMFX-2.5 drive a 20 mA load continuously?
Yes, LM4128BMFX-2.5 is rated for continuous 20 mA output current. However, power dissipation must be verified: at 20 mA and 400 mV dropout, power loss is 8 mW - well within the 350 mW absolute maximum rating at 25°C ambient. Thermal design should ensure junction temperature stays ≤125°C under worst-case conditions.
Is LM4128BMFX-2.5 qualified for automotive applications?
The LM4128BMFX-2.5 is not AEC-Q100 qualified; however, the pin-compatible LM4128BQ1MFX-2.5 (BQ grade) is AEC-Q100 Grade 1 qualified and manufactured on an Automotive Grade Flow. For automotive use, specify the Q-suffix variant to ensure compliance with automotive reliability and process requirements.
LM4128BMFX-2.5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Series
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±0.2%
- Temperature Coefficient:
- 75ppm/°C
- Noise - 0.1Hz to 10Hz:
- 275µVp-p
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- 2.9V ~ 5.5V
- Current - Supply:
- 100µA
- Current - Cathode:
- -
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM4128BMFX-2.5 FAQ
1.How can I place an order for LM4128BMFX-2.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4128BMFX-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 LM4128BMFX-2.5 reliable?
The price and inventory of LM4128BMFX-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 LM4128BMFX-2.5 is usually 5 days.
3.What payment methods are accepted for LM4128BMFX-2.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4128BMFX-2.5 transactions.
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4.How is shipping managed for LM4128BMFX-2.5?
LM4128BMFX-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4128BMFX-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 LM4128BMFX-2.5?
For technical support, including LM4128BMFX-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4128BMFX-2.5 requirements.
6.How does Aetrix verify that LM4128BMFX-2.5 is sourced from the original manufacturer or authorized distributors?
All LM4128BMFX-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 LM4128BMFX-2.5 meets industry standards.
7.What is the process for return or replacement of LM4128BMFX-2.5?
All LM4128BMFX-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM4128BMFX-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 LM4128BMFX-2.5 part is unused and in its original packaging.
Return procedure for LM4128BMFX-2.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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