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Texas Instruments LM4128BMFX-1.8
- Part No.:
- LM4128BMFX-1.8
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM4128BMFX-1.8.pdf
- Description:
- IC VREF SERIES 0.2% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,468
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Product details
Overview
LM4128BMFX-1.8 from National Semiconductor is a precision micropower series voltage reference in SOT-23-5 package, delivering 1.8 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, and operates across −40°C to +125°C - ideal for battery-powered instrumentation and portable data acquisition systems.
For engineers reviewing the LM4128BMFX-1.8 datasheet, LM4128BMFX-1.8 pinout, LM4128BMFX-1.8 application, or LM4128BMFX-1.8 equivalent, key selection criteria include dropout voltage (400 mV at 10 mA), line regulation (30 ppm/V), load regulation (25–120 ppm/mA), noise performance (170 µVPP, 0.1–10 Hz), and AEC-Q100-comparable B-grade stability for industrial embedded designs.
Technical Context
The LM4128BMFX-1.8 uses an internal band-gap-derived reference core with active output buffering, enabling stable operation without external compensation. Its series architecture eliminates idle current waste typical of shunt references, while the enable-controlled bias network reduces supply current to 3 µA in shutdown.
Designed for capacitive-load resilience, it maintains stability with ceramic output capacitors up to 10 µF and requires only a minimum 0.1 µF input capacitor. The 400 mV dropout voltage allows operation from low-headroom supplies such as single-cell Li-ion or regulated 2.2 V rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.8 V nominal; ±0.2% initial tolerance at 25°C ensures ≤±3.6 mV absolute error in precision ADC biasing |
| Temperature Coefficient | 75 ppm/°C max; contributes ≤±13.5 ppm over −40°C to +85°C ambient, critical for uncalibrated sensor front-ends |
| Quiescent Current | 60 µA typical; enables >1-year runtime on 200 mAh coin cell in always-on monitoring nodes |
| Dropout Voltage | 400 mV at 10 mA load; permits use with 2.2 V LDOs or single LiFePO₄ cells (2.5–3.65 V) |
| Enable Shutdown Current | 3 µA max; reduces system standby power by >95% vs active mode in duty-cycled sensors |
| Output Noise | 170 µVPP (0.1–10 Hz); supports 16-bit SAR ADCs without additional filtering in portable test gear |
| Line Regulation | 30 ppm/V; limits output drift to ≤54 ppm over 1.8 V ±0.1 V input variation in noisy DC-DC outputs |
Pinout & Package
SOT-23-5 package (NS package number MF05A), surface-mount, 1.6 mm × 2.9 mm footprint, 1.1 mm height, with exposed pad not connected internally.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | N/C | No-connect pin; must remain floating - no PCB trace or thermal pad connection |
| 2 | GND | Analog ground reference; requires low-impedance connection to clean 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 (i.e., ≥2.2 V) for regulation at full load |
| 5 | VREF | Precision 1.8 V output; capable of sourcing up to 20 mA; stable with 0–10 µF ceramic capacitive loads |
Key Features
| Feature | Design Value |
|---|---|
| Capacitor-free stability | Operates without mandatory output capacitor; eliminates risk of instability from ESR mismatch in ceramic caps |
| Micropower shutdown | 3 µA supply current in EN = low state enables ultra-low-power wake-on-event architectures |
| Low thermal hysteresis | 75 ppm over −40°C to +125°C cycling minimizes calibration drift in field-deployed equipment |
| High load drive | 20 mA output current supports direct driving of ADC reference inputs, op-amp bias networks, and DAC buffers |
| Robust short-circuit protection | Indefinite 75 mA current limit prevents damage during board-level testing or fault conditions |
Applications
| Portable Data Loggers | Industrial Sensor Transmitters |
|---|---|
Use Scenario: Battery-powered environmental monitors logging temperature, humidity, and pressure at 10-second intervals for 2+ years. IC Role / Device Role / Timing Role: Precision 1.8 V reference for 16-bit sigma-delta ADC and microcontroller VREF input. Use Value: 60 µA quiescent current and 3 µA shutdown extend battery life; 75 ppm/°C tempco maintains <±0.01% reading accuracy across outdoor temperature swings. |
Use Scenario: 4–20 mA loop-powered pressure transmitter operating in oil-field cabinets (−40°C to +85°C). IC Role / Device Role / Timing Role: Stable excitation source for bridge sensors and reference for analog signal conditioning. Use Value: 400 mV dropout enables regulation from 3.3 V loop-supply rail; −40°C to +125°C junction rating ensures reliability under cabinet heating. |
| Medical Wearables | Automotive Body Control Modules |
Use Scenario: ECG patch with ultra-low-power MCU, analog front-end, and Bluetooth LE radio. IC Role / Device Role / Timing Role: Low-noise 1.8 V reference for biopotential amplifier gain-setting and ADC conversion. Use Value: 170 µVPP (0.1–10 Hz) noise avoids signal degradation in sub-mV cardiac waveforms; SOT-23-5 saves PCB area in compact flex assemblies. |
Use Scenario: Door module controlling window lift, mirror fold, and interior lighting using CAN communication. IC Role / Device Role / Timing Role: Accuracy-critical reference for LIN bus transceiver bias and microcontroller ADC used in potentiometer feedback. Use Value: B-grade ±0.2% initial accuracy meets automotive functional safety requirements for non-safety-critical sensing; qualified per AEC-Q100 Grade 1 via LM4128BQ variants. |
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, 50 ppm/°C, 50 µA IQ, SOT-23-3 (no enable) | No enable pin; fixed operation only; lower tempco but higher cost | Select when shutdown control is unnecessary and tighter temperature drift is prioritized over micropower flexibility |
| MAX6029AEUR+T | 1.8 V, ±0.2% initial accuracy, 75 ppm/°C, 65 µA IQ, SOT-23-5 (enable pin) | Higher quiescent current; guaranteed 100 µA max IQ over temp; same pinout but different enable threshold (VIH = 1.4 V min) | Select when compatibility with 1.8 V logic-level enable signals is required and 5 µA IQ overhead is acceptable |
Compared with REF3018AIDBZR and MAX6029AEUR+T, the LM4128BMFX-1.8 uniquely balances 3 µA shutdown, 60 µA active IQ, and SOT-23-5 pin compatibility - making it optimal for space-constrained, intermittently powered systems where both ultra-low standby and moderate active consumption matter.
Availability
LM4128BMFX-1.8 is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor transmitters, battery-powered data loggers, and automotive body electronics requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for LM4128BMFX-1.8 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 series was designed specifically for micropower, high-accuracy voltage referencing in space- and energy-constrained applications - emphasizing low dropout, capacitor-free stability, and wide-temperature operation without trimming.
FAQ
What is the maximum input voltage for LM4128BMFX-1.8?
The LM4128BMFX-1.8 supports a maximum input voltage of 5.5 V, as specified in its Absolute Maximum Ratings. Operation above this level risks permanent damage. For reliable regulation, VIN must be ≥2.2 V (VREF + 400 mV) and ≤5.5 V, with optimal performance observed between 2.5 V and 5.0 V under typical load conditions.
Does LM4128BMFX-1.8 require an input capacitor?
Yes - the LM4128BMFX-1.8 requires a minimum 0.1 µF ceramic input capacitor (X5R or X7R) for stable operation, as stated in the Application Information section. When an output capacitor is used, CIN must be ≥ COUT. Omitting CIN may cause oscillation or startup failure, especially with high-impedance or noisy input sources.
Can LM4128BMFX-1.8 drive a 10 µF capacitive load?
Yes - the LM4128BMFX-1.8 is explicitly characterized for stability with capacitive loads up to 10 µF, including low-ESR ceramic types. This capability simplifies filtering in precision analog circuits and improves transient response without external compensation components.
What is the enable pin behavior for LM4128BMFX-1.8?
The EN pin on LM4128BMFX-1.8 is active-high with VIH ≥65% of VIN and VIL ≤35% of VIN. An internal 2 µA pull-up allows direct connection to VIN for always-on operation. When pulled low, supply current drops to ≤7 µA, placing the device in shutdown mode with VREF disabled and high-impedance output.
Is LM4128BMFX-1.8 qualified for automotive applications?
The LM4128BMFX-1.8 itself is not AEC-Q100 qualified; however, the pin-compatible LM4128BQ1MFX1.8 variant is AEC-Q100 Grade 1 qualified and manufactured on an automotive-grade flow. For automotive body electronics, designers should specify the Q-grade part to meet qualification and traceability requirements.
LM4128BMFX-1.8 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):
- 1.8V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±0.2%
- Temperature Coefficient:
- 75ppm/°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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM4128BMFX-1.8 FAQ
1.How can I place an order for LM4128BMFX-1.8 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4128BMFX-1.8 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-1.8 reliable?
The price and inventory of LM4128BMFX-1.8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4128BMFX-1.8 is usually 5 days.
3.What payment methods are accepted for LM4128BMFX-1.8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4128BMFX-1.8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4128BMFX-1.8?
LM4128BMFX-1.8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4128BMFX-1.8 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-1.8?
For technical support, including LM4128BMFX-1.8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4128BMFX-1.8 requirements.
6.How does Aetrix verify that LM4128BMFX-1.8 is sourced from the original manufacturer or authorized distributors?
All LM4128BMFX-1.8 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-1.8 meets industry standards.
7.What is the process for return or replacement of LM4128BMFX-1.8?
All LM4128BMFX-1.8 units undergo pre-shipment inspection (PSI). If there is an issue with LM4128BMFX-1.8, 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-1.8 part is unused and in its original packaging.
Return procedure for LM4128BMFX-1.8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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