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Texas Instruments LM4128AMF-2.5
- Part No.:
- LM4128AMF-2.5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM4128AMF-2.5.pdf
- Description:
- IC VREF SERIES 0.1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,072
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Product details
Overview
LM4128AMF-2.5 from National Semiconductor is a precision micropower series voltage reference in SOT-23-5 package, delivering 2.5 V output with ±0.1% initial accuracy, 75 ppm/°C temperature coefficient, and 60 µA quiescent current. It features an enable pin for 3 µA shutdown mode and supports up to 20 mA load current - ideal for high-accuracy ADC/DAC biasing in portable instrumentation.
For engineers reviewing the LM4128AMF-2.5 datasheet, LM4128AMF-2.5 pinout, LM4128AMF-2.5 application, or LM4128AMF-2.5 equivalent, key selection considerations include dropout voltage (175–400 mV), 0.1 Hz–10 Hz output noise (275 µVPP), line regulation (50 ppm/V), load regulation (25–120 ppm/mA), and thermal hysteresis (75 ppm) over −40°C to +125°C.
Technical Context
The LM4128AMF-2.5 uses a band-gap-derived reference core with internal enable control logic and low-dropout series architecture. Its design eliminates need for external stabilization capacitors while maintaining stability with capacitive loads up to 10 µF.
It operates across VIN = VREF + 400 mV to 5.5 V at 10 mA, delivers 2.5 V with guaranteed performance over −40°C to +125°C junction temperature, and integrates indefinite short-circuit protection limiting output current to 75 mA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.5 V nominal, ±0.1% initial accuracy at 25°C - ensures ≤±2.5 mV absolute error before calibration |
| Tempco | 75 ppm/°C max (A grade) - limits drift to ≤±23.4 µV/°C over full range |
| Quiescent Current | 60 µA typical - enables multi-year battery life in always-on sensor nodes |
| Dropout Voltage | 175–400 mV at 10 mA load - allows operation from 2.675 V supply in low-voltage systems |
| Shutdown Current | 3–7 µA with EN = 0 V - reduces standby power by >95% vs active mode |
| Output Noise | 275 µVPP (0.1–10 Hz) - supports 16-bit+ resolution in precision data acquisition |
| Line Regulation | 50 ppm/V - maintains <±125 µV output shift per volt input variation |
| Load Regulation | 25–120 ppm/mA - introduces ≤±300 µV error across full 20 mA load range |
Pinout & Package
SOT-23-5 package (NS package number MF05A), surface-mount, 1.6 mm × 2.9 mm footprint, rated for −40°C to +125°C junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | N/C | No-connect terminal - must remain unconnected and floating |
| 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 to activate reference output |
| 4 | VIN | Input supply rail - must exceed VREF + 400 mV (≥2.9 V) for regulation |
| 5 | VREF | Precision 2.5 V output - supplies stable bias to ADCs, DACs, or comparators |
Key Features
| Feature | Design Value |
|---|---|
| Enable-controlled shutdown | Reduces supply current to ≤7 µA - enables duty-cycled operation in energy-constrained IoT sensors |
| Capacitor-free stability | Operates without mandatory output capacitor - simplifies layout and reduces BOM count in space-constrained designs |
| Low-noise 2.5 V reference | 275 µVPP (0.1–10 Hz) - meets noise floor requirements for 16-bit SAR and delta-sigma converters |
| Indefinite short-circuit protection | Limits output current to 75 mA - prevents damage during test fixture miswiring or PCB assembly faults |
| Wide capacitive load tolerance | Stable with up to 10 µF ceramic output capacitance - improves transient response in dynamic load applications |
Applications
| Portable Data Loggers | Industrial Sensor Transmitters |
|---|---|
Use Scenario: Battery-powered environmental monitoring node sampling temperature, humidity, and pressure at 1 Hz with 16-bit ADC. IC Role / Device Role / Timing Role: Provides stable 2.5 V reference for ADC conversion and sensor excitation circuitry. Use Value: ±0.1% initial accuracy and 75 ppm/°C tempco ensure <±0.02% full-scale error over field temperature range without recalibration. |
Use Scenario: 4–20 mA loop-powered transmitter with HART interface in hazardous area instrumentation. IC Role / Device Role / Timing Role: Supplies precision reference for DAC-based current loop control and analog front-end signal conditioning. Use Value: 60 µA quiescent current and 3 µA shutdown mode allow microcontroller sleep states without compromising reference stability on wake-up. |
| Medical Patient Monitors | Automotive Battery Management Units |
Use Scenario: Portable ECG device acquiring biopotential signals with 24-bit delta-sigma ADC. IC Role / Device Role / Timing Role: Delivers ultra-low-noise 2.5 V reference for ADC reference input and op-amp biasing. Use Value: 275 µVPP (0.1–10 Hz) noise floor directly supports ≥110 dB SNR in clinical-grade signal chains. |
Use Scenario: Automotive BMS cell voltage measurement IC requiring high-accuracy voltage reference across −40°C to +125°C. IC Role / Device Role / Timing Role: Serves as primary reference for 12-bit SAR ADC measuring Li-ion cell voltages. Use Value: AEC-Q100 Grade 1 qualification (via LM4128AQ variants) and guaranteed 75 ppm/°C tempco ensure compliance with ASIL-B functional safety requirements. |
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, 100 ppm/°C tempco, 50 µA IQ, SOT-23-3 (no EN pin) | Lacks enable pin and has higher tempco - suitable only where shutdown not required and wider drift acceptable | Select when board space is critical and 3-pin simplicity outweighs need for low-power shutdown |
| ADR3425ARJZ-R7 | 2.5 V, ±0.1% initial accuracy, 10 ppm/°C max tempco, 120 µA IQ, SOT-23-5 (with EN) | Lower tempco but 2× higher supply current - better for wide-temp industrial control, worse for battery life | Prefer when long-term stability and extreme tempco performance dominate over quiescent power budget |
Compared with REF3025AIDBZR, LM4128AMF-2.5 adds enable control and tighter tempco at lower IQ; compared with ADR3425ARJZ-R7, it trades 10× lower quiescent current for higher tempco - making LM4128AMF-2.5 optimal for portable, battery-limited systems needing moderate drift control.
Availability
LM4128AMF-2.5 is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor transmitters, and medical data acquisition systems requiring stable component supply with consistent parametric performance across production lots.
Supply support for LM4128AMF-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 analog portfolio remains widely deployed in industrial and automotive systems.
The LM4128 series was designed specifically for micropower, space-constrained applications demanding high initial accuracy and low temperature drift - targeting portable test equipment, battery-powered sensors, and automotive subsystems.
FAQ
What is the minimum input voltage required for stable operation of the LM4128AMF-2.5?
The LM4128AMF-2.5 requires VIN ≥ VREF + 400 mV, i.e., ≥2.9 V, to maintain regulation at 10 mA load. At lighter loads, dropout decreases - e.g., 175 mV at 10 mA - but 2.9 V remains the guaranteed minimum for full-spec operation across temperature and process variation. Below this, output voltage drops nonlinearly.
Does the LM4128AMF-2.5 require an external output capacitor to remain stable?
No - the LM4128AMF-2.5 is internally compensated and stable without any output capacitor. An optional ceramic capacitor (up to 10 µF) may be added to improve load transient response, but it is not required for stability. Input capacitor CIN (≥0.1 µF) is mandatory for proper operation.
How does the enable pin (EN) function on the LM4128AMF-2.5?
The EN pin on the LM4128AMF-2.5 is active-high with internal ~2 µA pull-up. Driving EN ≥65% of VIN activates the reference; pulling EN ≤35% of VIN places LM4128AMF-2.5 in shutdown mode, reducing supply current to 3–7 µA. EN must never exceed VIN, and floating EN defaults to enabled via internal pull-up.
What is the output noise performance of the LM4128AMF-2.5, and how is it measured?
The LM4128AMF-2.5 delivers 275 µVPP output noise over 0.1 Hz to 10 Hz bandwidth - a key metric for high-resolution ADC applications. This value is measured under standard conditions (VIN = 5 V, ILOAD = 0 A, TJ = 25°C) using low-noise instrumentation and confirmed across production lots per National Semiconductor's characterization methodology.
Is the LM4128AMF-2.5 qualified for automotive applications?
The base LM4128AMF-2.5 is not AEC-Q100 qualified; however, the pin-compatible LM4128AQ1MF2.5 variant is AEC-Q100 Grade 1 qualified and manufactured on an automotive-grade flow. For automotive BMS or body control modules requiring qualification, LM4128AQ1MF2.5 - not LM4128AMF-2.5 - must be specified.
LM4128AMF-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:
- ±0.1%
- 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
LM4128AMF-2.5 FAQ
1.How can I place an order for LM4128AMF-2.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4128AMF-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 LM4128AMF-2.5 reliable?
The price and inventory of LM4128AMF-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 LM4128AMF-2.5 is usually 5 days.
3.What payment methods are accepted for LM4128AMF-2.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4128AMF-2.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4128AMF-2.5?
LM4128AMF-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4128AMF-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 LM4128AMF-2.5?
For technical support, including LM4128AMF-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4128AMF-2.5 requirements.
6.How does Aetrix verify that LM4128AMF-2.5 is sourced from the original manufacturer or authorized distributors?
All LM4128AMF-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 LM4128AMF-2.5 meets industry standards.
7.What is the process for return or replacement of LM4128AMF-2.5?
All LM4128AMF-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM4128AMF-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 LM4128AMF-2.5 part is unused and in its original packaging.
Return procedure for LM4128AMF-2.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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