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Texas Instruments LM4121IM5X-ADJ/NOPB
- Part No.:
- LM4121IM5X-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM4121IM5X-ADJ/NOPB.pdf
- Description:
- IC VREF SERIES ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,970
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Product details
Overview
LM4121IM5X-ADJ/NOPB from Texas Instruments is a precision micropower adjustable voltage reference IC in SOT-23-5 package, delivering 1.216 V nominal output with ±0.2% initial accuracy (Grade A), 50 ppm/°C temperature coefficient, ±5 mA source/sink capability, and 160 µA typical supply current - used for high-accuracy biasing and regulation in portable instrumentation and battery-powered analog signal chains.
For engineers reviewing the LM4121IM5X-ADJ/NOPB datasheet, LM4121IM5X-ADJ/NOPB pinout, LM4121IM5X-ADJ/NOPB application, or LM4121IM5X-ADJ/NOPB equivalent, key selection considerations include its adjustable output architecture, enable-controlled power-down mode (<2 µA), low dropout operation down to 1.8 V input, and compatibility with ceramic output capacitors as small as 0.022 µF.
Technical Context
The LM4121IM5X-ADJ/NOPB implements a bandgap-based reference core with an external feedback network via the ADJ pin, enabling programmable output voltages above 1.216 V using two resistors. Its internal amplifier drives both sourcing and sinking loads up to ±5 mA while maintaining stability with low-ESR ceramic capacitors.
Operation is controlled by an analog enable pin requiring ≥1.5 V for activation and ≤0.4 V for shutdown, with <2 µA quiescent current in power-down mode. The device guarantees performance over −40°C to +85°C ambient, with temperature coefficient and long-term stability (100 ppm over 1000 hrs) specified across −40°C to +125°C junction range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.216 V nominal, adjustable via external resistor divider - sets precise DC bias points for ADCs, DACs, and sensor interfaces. |
| Initial Accuracy | ±0.2% (Grade A) - ensures minimal calibration burden in precision measurement systems. |
| Tempco | 50 ppm/°C - maintains voltage stability across industrial temperature range without external compensation. |
| Supply Current | 160 µA typical - enables multi-year battery life in always-on monitoring nodes. |
| Enable Threshold | VH = 1.5 V, VL = 0.4 V - compatible with standard CMOS/TTL logic for low-power system control. |
| Min Input Voltage | 1.8 V at 5 mA load - supports direct operation from single Li-ion or two alkaline cells. |
| Noise (0.1–10 Hz) | 20 µVPP - preserves signal integrity in high-resolution data acquisition front-ends. |
Pinout & Package
SOT-23-5 (DBV) package: 2.9 mm × 1.6 mm × 1.45 mm body, gull-wing leads, RoHS-compliant matte tin lead finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - ADJ | Adjust Reference Input | Connects to resistor divider node; bias current flows out (15–40 nA), requiring low-impedance feedback path for accuracy. |
| 2 - GND | Ground Reference | Primary return path for load current and internal circuitry; requires low-inductance connection to minimize noise coupling. |
| 3 - EN | Enable Control | Analog input: >1.5 V enables output, <0.4 V disables output and reduces supply current to <2 µA. |
| 4 - IN | Positive Supply Input | Accepts 1.8–12 V; supplies internal bandgap and output stage; no input capacitor required but 0.1 µF recommended. |
| 5 - OUT | Reference Output | Delivers regulated voltage; stable with 0.022–0.047 µF ceramic capacitor (ESR < 0.5 Ω); supports ±5 mA load. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Output Architecture | Enables user-defined output voltages >1.216 V using external resistors - avoids fixed-voltage limitations in multi-rail systems. |
| Ultra-Low Quiescent Current | 160 µA typical operating current and <2 µA shutdown current - extends battery runtime in portable medical and IoT sensors. |
| Low-Voltage Operation | Functions down to 1.8 V input - eliminates need for pre-regulation when powered from single-cell batteries. |
| Source/Sink Capability | ±5 mA output drive - directly biases op-amp inputs, ADC references, or small transducers without external buffers. |
| Ceramic Capacitor Stability | Stable with 0.022 µF minimum ceramic output capacitor - reduces BOM cost and board area vs. tantalum alternatives. |
Applications
| Portable Instrumentation | Battery-Powered Sensors |
|---|---|
Use Scenario: Handheld multimeter with 24-bit sigma-delta ADC requiring stable 2.5 V reference. IC Role / Device Role / Timing Role: Precision voltage reference providing excitation and conversion reference for analog front-end. Use Value: ±0.2% initial accuracy and 50 ppm/°C tempco ensure <0.01% full-scale error across operating temperature without recalibration. | Use Scenario: Wireless environmental sensor node logging temperature/humidity with 10-year battery life target. IC Role / Device Role / Timing Role: Low-power reference for ADC and analog signal conditioning during active measurement cycles. Use Value: 160 µA supply current and enable-controlled shutdown reduce average system current to sub-µA levels between readings. |
| Industrial Process Monitoring | Medical Vital Sign Acquisition |
Use Scenario: Loop-powered 4–20 mA transmitter with HART modulation requiring stable 1.25 V reference. IC Role / Device Role / Timing Role: Primary reference for current-loop DAC and sensor signal conditioning under wide ambient temperature swings. Use Value: Guaranteed 50 ppm/°C tempco over −40°C to +125°C junction range ensures compliance with IEC 61000-6-2 industrial immunity requirements. | Use Scenario: Portable ECG monitor with 12-bit SAR ADC sampling at 1 kSPS and clinical-grade baseline stability. IC Role / Device Role / Timing Role: Low-noise reference (20 µVPP) for analog front-end gain stages and ADC reference input. Use Value: Sub-20 µVPP 0.1–10 Hz noise prevents baseline wander and preserves microvolt-level ST-segment resolution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM4040CIM3-ADJ/NOPB | Shunt reference topology; requires external current source; 0.5% initial accuracy; 100 ppm/°C tempco. | Higher supply sensitivity; less suitable for low-input-voltage or high-source-impedance designs. | Select when board space allows series dropping resistor and higher tempco is acceptable. |
| REF3012AIDBZR | Fixed 1.2 V output; 0.2% accuracy; 50 ppm/°C; 50 µA supply current; no enable pin. | Lacks adjustability and power-down control; optimized for ultra-low-quiescent-current fixed-voltage use cases. | Select when output voltage is fixed and lowest possible operating current is critical. |
Compared with LM4121IM5X-ADJ/NOPB, LM4040CIM3-ADJ/NOPB demands higher minimum cathode current and offers lower accuracy, while REF3012AIDBZR trades adjustability and enable functionality for 3× lower supply current and smaller footprint - making LM4121IM5X-ADJ/NOPB optimal for adjustable, low-voltage, power-gated precision references.
Availability
LM4121IM5X-ADJ/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered sensors, and industrial process monitoring requiring stable component supply with guaranteed long-term availability.
Supply support for LM4121IM5X-ADJ/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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and digital signal processing technologies.
The LM4121 product line delivers precision micropower voltage references for battery-constrained and thermally demanding applications - designed specifically for high-accuracy analog signal chains in portable, industrial, and medical equipment.
FAQ
What is the output voltage range of the LM4121IM5X-ADJ/NOPB?
The LM4121IM5X-ADJ/NOPB has a nominal reference voltage of 1.216 V at the ADJ pin and supports adjustable output voltages above this value using an external resistor divider. The output is not internally limited, but practical upper bound depends on input voltage headroom and load conditions - typically up to VIN − 0.3 V. The LM4121IM5X-ADJ/NOPB does not support outputs below 1.216 V.
How does the enable pin function on the LM4121IM5X-ADJ/NOPB?
The enable pin (Pin 3) of the LM4121IM5X-ADJ/NOPB is an analog control input: applying ≥1.5 V activates the output, while ≤0.4 V forces shutdown with supply current dropping below 2 µA. It exhibits minimal hysteresis and requires ~6 µA input current. Floating the pin is not recommended; tie to VIN if shutdown is unused. This behavior is fully characterized in the LM4121IM5X-ADJ/NOPB datasheet's Electrical Characteristics table.
Can the LM4121IM5X-ADJ/NOPB drive a 5 mA load continuously?
Yes, the LM4121IM5X-ADJ/NOPB is rated for continuous ±5 mA source/sink current at the output pin (Pin 5) across −40°C to +85°C. Load regulation remains within 0.1 %/mA up to 5 mA, and thermal limits permit sustained operation at full load when ambient temperature and PCB copper area meet the 280 °C/W θJA specification. Derating applies above 85°C ambient per the Absolute Maximum Ratings table in the LM4121IM5X-ADJ/NOPB datasheet.
What output capacitor is required for stability with the LM4121IM5X-ADJ/NOPB?
The LM4121IM5X-ADJ/NOPB requires a minimum 0.022 µF ceramic capacitor at the output (Pin 5) for guaranteed stability. Capacitors from 0.022 µF to 0.047 µF are fully supported with ESR < 0.5 Ω. Larger values (up to 1 µF) may be used with tantalum types, but require a 50 pF capacitor between OUT and ADJ pins. The LM4121IM5X-ADJ/NOPB datasheet specifies these values in the Application Hints section and Figure 34.
Is the LM4121IM5X-ADJ/NOPB RoHS compliant and what is its moisture sensitivity level?
Yes, the LM4121IM5X-ADJ/NOPB is RoHS compliant with matte tin (SN) lead finish and carries a JEDEC MSL Level-1 rating (unlimited floor life at ≤30°C/60% RH), qualified for peak reflow temperatures up to 260°C. This information is confirmed in the TI Package Option Addendum for LM4121IM5X-ADJ/NOPB, dated 24-Jul-2026.
LM4121IM5X-ADJ/NOPB 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:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.216V
- Voltage - Output (Max):
- 12 V
- Current - Output:
- 5 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- 50ppm/°C
- Noise - 0.1Hz to 10Hz:
- 20µVp-p
- Noise - 10Hz to 10kHz:
- 30µVrms
- Voltage - Input:
- 1.5V ~ 12V
- Current - Supply:
- 275µA
- Current - Cathode:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM4121IM5X-ADJ/NOPB FAQ
1.How can I place an order for LM4121IM5X-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4121IM5X-ADJ/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 LM4121IM5X-ADJ/NOPB reliable?
The price and inventory of LM4121IM5X-ADJ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4121IM5X-ADJ/NOPB is usually 5 days.
3.What payment methods are accepted for LM4121IM5X-ADJ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4121IM5X-ADJ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4121IM5X-ADJ/NOPB?
LM4121IM5X-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4121IM5X-ADJ/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 LM4121IM5X-ADJ/NOPB?
For technical support, including LM4121IM5X-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4121IM5X-ADJ/NOPB requirements.
6.How does Aetrix verify that LM4121IM5X-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM4121IM5X-ADJ/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 LM4121IM5X-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LM4121IM5X-ADJ/NOPB?
All LM4121IM5X-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM4121IM5X-ADJ/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 LM4121IM5X-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LM4121IM5X-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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