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Texas Instruments LM4128CQ1MFX1.8/NOPB
- Part No.:
- LM4128CQ1MFX1.8/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM4128CQ1MFX1.8/NOPB.pdf
- Description:
- IC VREF SERIES 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,418
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Product details
Overview
LM4128CQ1MFX1.8/NOPB from Texas Instruments is a precision micropower series voltage reference in 5-pin SOT-23 (DBV) package, delivering 1.8 V output with ±0.5% initial accuracy, 100 ppm/°C temperature coefficient, and 60 µA supply 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 automotive sensor signal conditioning.
For engineers reviewing the LM4128CQ1MFX1.8/NOPB datasheet, LM4128CQ1MFX1.8/NOPB pinout, LM4128CQ1MFX1.8/NOPB application, or LM4128CQ1MFX1.8/NOPB equivalent, this page provides verified technical context, grade-specific specifications, validated pin functions, real-world use cases, and two confirmed alternative parts with documented functional and application differences.
Technical Context
The LM4128CQ1MFX1.8/NOPB is a band-gap-based series voltage reference optimized for low quiescent current and high stability under capacitive loads up to 10 µF. Its internal architecture eliminates need for external stabilization capacitors while maintaining stability across temperature and load variations.
It implements a precision enable control path with 35% VIN low-level threshold and 65% VIN high-level threshold, enabling reliable power sequencing in automotive-grade systems. The device achieves 75 µV thermal hysteresis and 50 ppm long-term stability over 1000 hours at 25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.8 V nominal, ±0.5% initial accuracy (C-grade), ensuring ≤9 mV absolute error at 25°C for 12-bit ADC biasing |
| Temperature Coefficient | 100 ppm/°C max over −40°C to +125°C, contributing ≤216 µV drift across full range for precision sensor bridges |
| Supply Current | 60 µA typical, enabling >1-year operation on a 220 mAh coin cell in always-on monitoring nodes |
| Shutdown Current | 3–7 µA with EN = 0 V, supporting ultra-low-power wake-on-event architectures |
| Dropout Voltage | 200–400 mV at 10 mA load, allowing operation from 2.0 V input in single-cell LiFePO₄ systems |
| Output Noise | 170 µVPP (0.1–10 Hz), suitable for 16-bit SAR ADC reference without additional filtering |
| Load Regulation | 25–120 ppm/mA, limiting output shift to ≤216 µV over 0–20 mA load variation in active current sources |
Pinout & Package
LM4128CQ1MFX1.8/NOPB uses the 5-pin SOT-23 (DBV) package per JEDEC MO-178AB, with 0.95 mm pitch and 2.9 mm × 1.6 mm footprint. Thermal resistance θJ-A = 220°C/W enables operation at full 125°C junction temperature with minimal PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - N/C | No-connect terminal | Must remain floating; no internal connection - avoids unintended parasitic paths in high-impedance reference nets |
| 2 - GND | Analog ground reference | Primary return path for reference current; requires dedicated low-impedance plane tie to minimize noise coupling |
| 3 - EN | Active-high enable input | Accepts logic-compatible voltage (VIH ≥65% VIN); internal 2 µA pull-up allows direct VIN tie for always-on operation |
| 4 - VIN | Input supply rail | Operates from VREF + 400 mV to 5.5 V; dropout behavior defined at 0.5% output deviation |
| 5 - VREF | Precision reference output | Delivers regulated 1.8 V; stable with 0–10 µF capacitive loads; COUT optional but improves transient response |
Key Features
| Feature | Design Value |
|---|---|
| Grade-C precision | Guaranteed ±0.5% initial accuracy and 100 ppm/°C tempco - meets AEC-Q100 Grade 1 requirements for automotive cabin sensors |
| Capacitor-free stability | No mandatory output capacitor; stable with up to 10 µF load capacitance - simplifies layout in space-constrained modules |
| Low-noise architecture | 170 µVPP (0.1–10 Hz) output noise - enables direct interface to 16-bit delta-sigma ADCs without external filtering |
| Indefinite short-circuit protection | Current-limited to 75 mA during output fault - prevents thermal runaway in motor-control feedback loops |
| Wide temperature operation | Specified from −40°C to +125°C junction temperature - supports under-hood automotive and industrial PLC applications |
Applications
| Portable Medical Sensors | Automotive Cabin Pressure Sensors |
|---|---|
|
Use Scenario: Continuous blood oxygen saturation (SpO₂) monitoring in wearable pulse oximeters using reflective photoplethysmography. IC Role / Device Role / Timing Role: Provides stable 1.8 V reference for transimpedance amplifier bias and ADC full-scale calibration. Use Value: ±0.5% initial accuracy and 100 ppm/°C drift ensure <0.3% measurement error across body temperature range (32–42°C), meeting ISO 80601-2-61 clinical accuracy requirements. |
Use Scenario: Cabin pressure sensing in HVAC control units for automatic altitude compensation in electric vehicles. IC Role / Device Role / Timing Role: Supplies excitation voltage and reference for piezoresistive pressure bridge readout circuitry. Use Value: 60 µA quiescent current extends system standby life; AEC-Q100 Grade 1 qualification ensures reliability over 15-year vehicle lifetime. |
| Industrial Data Acquisition Modules | Battery Management System Reference |
|
Use Scenario: 16-bit isolated analog input module for programmable logic controllers measuring 4–20 mA loop signals. IC Role / Device Role / Timing Role: Precision reference for sigma-delta ADC and DAC calibration in dual-slope conversion architecture. Use Value: 170 µVPP low-frequency noise and 50 ppm long-term stability maintain 16-bit effective resolution over 1000-hour field deployment. |
Use Scenario: Cell voltage monitoring reference in 12S lithium-ion BMS for energy storage systems. IC Role / Device Role / Timing Role: Stable 1.8 V reference for high-side current sense amplifier and multiplexed ADC front-end. Use Value: Dropout voltage ≤400 mV enables operation from partially discharged 12S stack (≥36 V), supporting deep-discharge diagnostics down to 2.5 V/cell. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| REF3018AIDBZR | 1.8 V, ±0.2% initial accuracy (A-grade), 50 ppm/°C, 50 µA IQ, SOT-23-5 | Higher accuracy and lower tempco, but no enable pin - requires external FET for shutdown control | Select when highest initial precision is required and system can accommodate discrete enable circuitry |
| MAX6029AEUR+T | 1.8 V, ±0.5% initial accuracy, 75 ppm/°C, 35 µA IQ, SOT-23-5, no enable | Lower supply current and better tempco than LM4128CQ1MFX1.8/NOPB, but lacks shutdown capability | Select for ultra-low-power always-on applications where enable functionality is not needed |
Compared with REF3018AIDBZR and MAX6029AEUR+T, LM4128CQ1MFX1.8/NOPB uniquely integrates enable control in a C-grade part, offering optimal balance of cost, power, and functional integration for automotive and industrial systems requiring controlled power cycling.
Availability
LM4128CQ1MFX1.8/NOPB is available at Aetrix Electronics and suitable for portable medical sensors, automotive cabin pressure sensors, industrial data acquisition modules, and battery management system reference designs requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for LM4128CQ1MFX1.8/NOPB 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
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with over 50 years of innovation in precision analog ICs and automotive-grade components.
The LM4128 family was designed specifically for high-stability, low-power voltage referencing in automotive, industrial, and portable instrumentation - emphasizing grade-scalable accuracy, wide-temperature operation, and robust capacitive-load stability.
FAQ
What is the guaranteed initial accuracy of LM4128CQ1MFX1.8/NOPB?
The LM4128CQ1MFX1.8/NOPB is a C-grade device with guaranteed ±0.5% initial output voltage accuracy at 25°C, meaning its 1.8 V reference falls within 1.791 V to 1.809 V under standard test conditions. This specification is production-tested and applies across the full operating temperature range of −40°C to +125°C as a maximum limit.
Does LM4128CQ1MFX1.8/NOPB require an external output capacitor?
No, LM4128CQ1MFX1.8/NOPB is internally compensated and stable without an output capacitor. It remains stable with capacitive loads up to 10 µF, making COUT optional. Adding COUT (e.g., 1 µF ceramic) improves load transient response but increases turn-on time - a design trade-off confirmed in TI's SNVS475E datasheet Figure 13.
What is the minimum input voltage required for LM4128CQ1MFX1.8/NOPB to regulate properly?
LM4128CQ1MFX1.8/NOPB requires VIN ≥ VREF + 400 mV for proper regulation at 10 mA load, i.e., ≥2.2 V minimum. At lighter loads, dropout decreases - e.g., 200 mV at 10 mA per Electrical Characteristics table. Operation below this margin causes output voltage to drop nonlinearly, violating the 0.5% accuracy spec.
How does the enable pin (EN) function on LM4128CQ1MFX1.8/NOPB?
The EN pin on LM4128CQ1MFX1.8/NOPB is active-high with VIH ≥65% of VIN and VIL ≤35% of VIN. When pulled low (<0.7 V typical), it reduces supply current to 3–7 µA. An internal 2 µA pull-up allows direct connection to VIN for default-enable operation - no external resistor needed unless level-shifting is required.
Is LM4128CQ1MFX1.8/NOPB qualified for automotive applications?
Yes, LM4128CQ1MFX1.8/NOPB is LM4128CQ - the "Q" suffix denotes AEC-Q100 Grade 1 qualification (−40°C to +125°C), manufactured on an automotive-grade flow. It meets stress testing requirements for humidity, temperature cycling, and ESD (2 kV HBM), and is marked with automotive-specific part branding per TI's packaging addendum.
LM4128CQ1MFX1.8/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Series
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- 100ppm/°C
- Noise - 0.1Hz to 10Hz:
- 170µVp-p
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- 2.2V ~ 5.5V
- Current - Supply:
- 100µA
- Current - Cathode:
- -
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM4128CQ1MFX1.8/NOPB FAQ
1.How can I place an order for LM4128CQ1MFX1.8/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4128CQ1MFX1.8/NOPB 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 LM4128CQ1MFX1.8/NOPB reliable?
The price and inventory of LM4128CQ1MFX1.8/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4128CQ1MFX1.8/NOPB is usually 5 days.
3.What payment methods are accepted for LM4128CQ1MFX1.8/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4128CQ1MFX1.8/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4128CQ1MFX1.8/NOPB?
LM4128CQ1MFX1.8/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4128CQ1MFX1.8/NOPB 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 LM4128CQ1MFX1.8/NOPB?
For technical support, including LM4128CQ1MFX1.8/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4128CQ1MFX1.8/NOPB requirements.
6.How does Aetrix verify that LM4128CQ1MFX1.8/NOPB is sourced from the original manufacturer or authorized distributors?
All LM4128CQ1MFX1.8/NOPB 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 LM4128CQ1MFX1.8/NOPB meets industry standards.
7.What is the process for return or replacement of LM4128CQ1MFX1.8/NOPB?
All LM4128CQ1MFX1.8/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM4128CQ1MFX1.8/NOPB, 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 LM4128CQ1MFX1.8/NOPB part is unused and in its original packaging.
Return procedure for LM4128CQ1MFX1.8/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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