My Inquiry
My Account
Texas Instruments LM4128CMF-2.5
- Part No.:
- LM4128CMF-2.5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM4128CMF-2.5.pdf
- Description:
- IC VREF SERIES 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,682
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM4128CMF-2.5 from National Semiconductor is a precision micropower series voltage reference in SOT-23-5 package, delivering 2.5 V output with ±0.5% initial accuracy, 100 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, and operates from −40°C to +125°C - ideal for battery-powered instrumentation and portable data acquisition systems.
For engineers reviewing the LM4128CMF-2.5 datasheet, LM4128CMF-2.5 pinout, LM4128CMF-2.5 application, or LM4128CMF-2.5 equivalent, key selection considerations include its C-grade accuracy (±0.5%), dropout voltage of 175–400 mV at 10 mA, 275 µVPP (0.1–10 Hz) output noise, line regulation of 50 ppm/V, and compatibility with capacitive loads up to 10 µF without external stabilization.
Technical Context
The LM4128CMF-2.5 uses a band-gap-derived reference core optimized for low-power operation and high stability across temperature. Its series architecture eliminates idle current waste typical of shunt references, enabling efficient use in low-quiescent-current systems.
It integrates an enable control input (EN) that places the device in ultra-low-power shutdown (3–7 µA), while maintaining full functionality upon reactivation. The design ensures stability with ceramic output capacitors up to 10 µF and requires only a minimum 0.1 µF input capacitor for robust operation under varying load and supply conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.5 V nominal; fixed precision reference for ADC/DAC biasing and sensor excitation |
| Initial Accuracy | ±0.5% at 25°C (C grade); defines maximum offset error before calibration |
| Tempco | 100 ppm/°C max (−40°C to +125°C); limits drift-induced error in wide-temperature industrial environments |
| Quiescent Current | 60 µA typical; enables multi-year battery life in always-on portable equipment |
| Dropout Voltage | 175–400 mV at 10 mA load; allows operation from 2.675 V input in low-voltage systems |
| Output Noise | 275 µVPP (0.1–10 Hz); suitable for 16-bit+ data converters requiring low-noise reference |
| Enable Shutdown Current | 3–7 µA; reduces system standby power when reference not actively needed |
Pinout & Package
SOT-23-5 package (NS Package Number MF05A), surface-mount, 1.6 mm × 2.9 mm footprint with 0.95 mm pitch; thermally enhanced for operation up to +125°C junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | N/C | No-connect pin; must remain unconnected and floating per datasheet |
| 2 | GND | Analog ground reference; requires low-impedance connection to system ground plane |
| 3 | EN | Active-high enable input; ≥65% of VIN required for activation; internal 2 µA pull-up allows direct tie-to-VIN |
| 4 | VIN | Input supply rail; must exceed VREF + 400 mV (≥2.9 V for 2.5 V output) and stay ≤5.5 V |
| 5 | VREF | Precision 2.5 V output; drives loads up to 20 mA; stable with 0–10 µF capacitive loading |
Key Features
| Feature | Design Value |
|---|---|
| Enable-controlled shutdown | Reduces supply current to 3–7 µA, enabling power-gating in energy-constrained systems |
| No external stabilization capacitor required | Eliminates BOM cost and layout area for compensation cap; simplifies design validation |
| Stable with up to 10 µF capacitive load | Supports fast transient response in high-capacitance sensor interfaces and regulated analog rails |
| Indefinite short-circuit protection | Limits output current to 75 mA during fault, preventing damage during test or miswiring |
| Low thermal hysteresis (75 ppm) | Minimizes repeatability error after thermal cycling - critical for precision metrology applications |
Applications
| Portable Data Acquisition | Battery-Powered Instrumentation |
|---|---|
Use Scenario: Handheld multimeter acquiring 16-bit ADC samples in field environments with variable ambient temperature. IC Role / Device Role / Timing Role: Provides stable 2.5 V reference for SAR ADC conversion, directly determining measurement resolution and accuracy. Use Value: ±0.5% initial accuracy and 100 ppm/°C tempco ensure <1 LSB error over full operating range without recalibration. |
Use Scenario: Portable gas analyzer using electrochemical sensors requiring precise bias voltage and low-noise excitation. IC Role / Device Role / Timing Role: Supplies regulated 2.5 V excitation to sensor front-end and reference to signal-chain ADC/DAC. Use Value: 275 µVPP (0.1–10 Hz) noise and 60 µA quiescent current extend battery life while preserving sensor signal fidelity. |
| Industrial Process Control | Automotive Onboard Diagnostics |
Use Scenario: Loop-powered 4–20 mA transmitter in factory automation, operating continuously at 85°C ambient. IC Role / Device Role / Timing Role: Precision reference for current-loop DAC and sensor signal conditioning within tight thermal envelope. Use Value: −40°C to +125°C junction rating and 100 ppm/°C tempco maintain calibration integrity across harsh industrial thermal cycles. |
Use Scenario: OBD-II diagnostic module monitoring battery voltage, coolant temperature, and throttle position in engine control units. IC Role / Device Role / Timing Role: Supplies stable reference to microcontroller ADC inputs and analog comparators for fault detection. Use Value: Enable pin allows synchronized power-down during vehicle sleep mode, reducing parasitic drain below 10 µA. |
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) | Higher accuracy and lower tempco, but lacks enable control and uses 3-pin SOT-23 | Select when higher precision is prioritized over shutdown capability and board space is constrained |
| MAX6025AEUR+T | 2.5 V, ±0.1% initial accuracy, 30 ppm/°C, 65 µA IQ, SOT-23-3 (no EN) | Superior stability and lower noise (12 µVRMS), but no enable function and automotive qualification not specified | Prefer for high-end test equipment where long-term drift and thermal stability dominate requirements |
Compared with LM4128CMF-2.5, REF3025AIDBZR offers tighter accuracy and lower tempco but sacrifices programmable shutdown; MAX6025AEUR+T delivers best-in-class stability yet lacks enable control and automotive-grade qualification - making LM4128CMF-2.5 the optimal balance of C-grade precision, ultra-low shutdown current, and AEC-Q100-compatible variants (CQ grade available).
Availability
LM4128CMF-2.5 is available at Aetrix Electronics and suitable for portable instrumentation, industrial process transmitters, and automotive diagnostics requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LM4128CMF-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; known for high-performance precision analog ICs including voltage references, amplifiers, and data converters.
The LM4128 series was designed specifically for space-constrained, battery-operated systems needing micropower precision references with enable control - targeting instrumentation, portable test gear, and automotive subsystems.
FAQ
What is the guaranteed initial accuracy of LM4128CMF-2.5 over temperature?
The LM4128CMF-2.5 has a guaranteed initial accuracy of ±0.5% at 25°C (C grade), with temperature coefficient limited to 100 ppm/°C over −40°C to +125°C. This means total output deviation remains within ±0.5% + (100 ppm/°C × ΔT) across the full operating range - e.g., ±0.6% at 125°C. These values are production-tested and documented in the Electrical Characteristics table for LM4128-2.5.
Does LM4128CMF-2.5 require an external input capacitor?
Yes - the LM4128CMF-2.5 requires a minimum 0.1 µF ceramic input capacitor (X5R/X7R) for stable operation, as specified in the Application Information section. If an output capacitor is used, the input capacitor must be ≥ its value. Larger input capacitors (4.7–22 µF) further reduce output noise and startup overshoot, especially in noisy supply environments.
Can LM4128CMF-2.5 drive a 10 µF capacitive load?
Yes - the LM4128CMF-2.5 is explicitly characterized for stability with capacitive loads up to 10 µF, eliminating need for external compensation. This capability supports fast load-transient response in applications like sensor biasing and regulated analog supplies, and is verified in Typical Performance Characteristics (Figure 20211055, Load Regulation).
What is the minimum input voltage required for LM4128CMF-2.5 to regulate at 2.5 V?
The LM4128CMF-2.5 requires VIN ≥ VREF + 400 mV = 2.9 V for proper regulation at 10 mA load. Dropout voltage is specified as 175–400 mV (min–max) under those conditions. At lighter loads, dropout decreases - e.g., ~200 mV at 1 mA - enabling operation down to ~2.7 V input in low-current applications.
Is LM4128CMF-2.5 qualified for automotive applications?
The base LM4128CMF-2.5 is not automotive-qualified, but its pin-compatible variant LM4128CQ1MF2.5 is AEC-Q100 Grade 1 qualified and manufactured on an Automotive Grade Flow. That version shares identical electrical specs (±0.5%, 100 ppm/°C, 60 µA IQ) and adds enhanced defect detection and reliability testing for under-hood and chassis applications.
LM4128CMF-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:
- ±0.5%
- Temperature Coefficient:
- 100ppm/°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
LM4128CMF-2.5 FAQ
1.How can I place an order for LM4128CMF-2.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4128CMF-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 LM4128CMF-2.5 reliable?
The price and inventory of LM4128CMF-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 LM4128CMF-2.5 is usually 5 days.
3.What payment methods are accepted for LM4128CMF-2.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4128CMF-2.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4128CMF-2.5?
LM4128CMF-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4128CMF-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 LM4128CMF-2.5?
For technical support, including LM4128CMF-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4128CMF-2.5 requirements.
6.How does Aetrix verify that LM4128CMF-2.5 is sourced from the original manufacturer or authorized distributors?
All LM4128CMF-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 LM4128CMF-2.5 meets industry standards.
7.What is the process for return or replacement of LM4128CMF-2.5?
All LM4128CMF-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM4128CMF-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 LM4128CMF-2.5 part is unused and in its original packaging.
Return procedure for LM4128CMF-2.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM4128CMF-2.5 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
