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Texas Instruments LP2981IM5X-3.3/NOPB
- Part No.:
- LP2981IM5X-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LP2981IM5X-3.3/NOPB.pdf
- Description:
- IC REG LINEAR 3.3V 100MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:5,724
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Product details
Overview
LP2981IM5X-3.3/NOPB from Texas Instruments is a fixed 3.3V, 100mA low-dropout (LDO) regulator in SOT-23-5 package, featuring ±0.5% output voltage accuracy (A-grade), 175mV dropout at 100mA, 75dB PSRR at 1kHz, and operation from –40°C to +125°C. It powers low-voltage microcontrollers in electricity meters and micro-inverters.
For engineers reviewing the LP2981IM5X-3.3/NOPB datasheet, LP2981IM5X-3.3/NOPB pinout, LP2981IM5X-3.3/NOPB application, or LP2981IM5X-3.3/NOPB equivalent, key selection criteria include dropout performance under load, PSRR at switching frequencies up to 1MHz, shutdown current ≤1.75μA, stability with 2.2µF ceramic output capacitors, and thermal shutdown at 170°C.
Technical Context
The LP2981IM5X-3.3/NOPB implements a CMOS pass transistor architecture with internal bandgap reference and error amplifier, enabling tight regulation across line, load, and temperature. Its UVLO circuit activates at 2.2V (rising) with 130mV hysteresis, ensuring reliable startup under brownout conditions.
It integrates active-high enable (ON/OFF) with internal pulldown for controlled discharge during disable, soft-start to limit inrush current, and thermal shutdown with 20°C hysteresis (170°C trip, 150°C reset). Protection includes current limiting (150mA short-circuit) and overtemperature shutdown.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±0.5% (A-grade, full load/temperature range) |
| Max Output Current | 100mA continuous - supports MCU core rails and sensor interfaces |
| Dropout Voltage | 175mV at 100mA - enables operation from 3.475V input in 3.3V systems |
| PSRR | 75dB at 1kHz, 45dB at 1MHz - suppresses DC/DC switching noise upstream |
| Quiescent Current | 620μA at 100mA load - balances efficiency and transient response |
| Shutdown Current | ≤1.75μA - preserves battery life in always-on metering applications |
| Operating Temp | –40°C to +125°C junction - qualified for industrial and energy infrastructure use |
Pinout & Package
LP2981IM5X-3.3/NOPB uses the DBV (SOT-23-5) package: 2.9mm × 2.8mm footprint, 5-pin surface-mount, with exposed pad not connected internally.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (IN) | Input supply | Accepts 2.5V–16V; requires ≥1µF ceramic capacitor to GND for stability |
| 2 (GND) | Ground reference | Common substrate return; connects to PCB ground plane for thermal and noise control |
| 3 (ON/OFF) | Enable control | Active-high logic: >0.85V enables regulator; <0.15V disables with internal pulldown |
| 4 (NC) | No connect | Factory test/calibration pin - must remain floating; no external connection permitted |
| 5 (OUT) | Regulated output | Delivers 3.3V; requires ≥2.2µF ceramic capacitor to GND for stability and PSRR optimization |
Key Features
| Feature | Design Value |
|---|---|
| Stable with 2.2µF ceramic output cap | Eliminates need for tantalum or electrolytic capacitors - reduces BOM cost and board area |
| 75dB PSRR at 1kHz | Attenuates upstream DC/DC ripple before reaching sensitive analog or RF circuitry |
| Internal soft-start | Controls inrush current during power-up - avoids input rail sag and reduces required input capacitance |
| Thermal shutdown with hysteresis | Shuts down at 170°C and re-enables at 150°C - prevents thermal cycling damage in enclosed enclosures |
| ±0.5% output accuracy (A-grade) | Meets tight tolerance requirements of 3.3V I/O domains and precision ADC references |
Applications
| Electricity Meters | Micro Inverters |
|---|---|
Use Scenario: Powering metrology ICs, real-time clocks, and communication modules in smart electricity meters operating in sealed outdoor enclosures. IC Role / Device Role / Timing Role: Primary 3.3V LDO supplying isolated MCU and RF transceiver subsystems. Use Value: ±0.5% output accuracy ensures consistent ADC reference and RTC timing across temperature; 125°C rating supports extended ambient operation. | Use Scenario: Providing stable 3.3V bias to gate drivers, isolation controllers, and monitoring sensors in residential solar micro-inverter power stages. IC Role / Device Role / Timing Role: Post-regulator for DC/DC converter outputs, cleaning high-frequency switching noise before sensitive control logic. Use Value: 75dB PSRR at 1kHz suppresses 100kHz–500kHz DC/DC ripple; 175mV dropout allows efficient operation from 12V intermediate bus. |
| Server PSU Monitoring | Residential Breakers |
Use Scenario: Supplying auxiliary 3.3V rails for PMBus/I²C monitoring ICs and fault-detection comparators in 12V server power supplies. IC Role / Device Role / Timing Role: Always-on LDO powering health-monitoring circuitry independent of main CPU rail. Use Value: ≤1.75μA shutdown current minimizes standby loss; UVLO (2.2V rising) prevents erratic behavior during brownout recovery. | Use Scenario: Powering arc-fault detection processors and wireless communication modules in modern AFCI/GFCI residential circuit breakers. IC Role / Device Role / Timing Role: Main 3.3V regulator for embedded safety-critical MCU and RF SoC. Use Value: –40°C to +125°C operation accommodates enclosure temperature extremes; integrated thermal shutdown protects against sustained overload. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV70733PDQNR | Lower IQ (25μA vs 620μA at 100mA), 200mA output, but only 65dB PSRR at 1kHz and requires 1µF min COUT | Better suited for ultra-low-power battery-backed systems; less effective for high-ripple DC/DC post-regulation | Select when quiescent current dominates design priority over PSRR and thermal robustness |
| MCP1700T-3302E/TT | 250mA output, 6μA IQ, but ±2% output accuracy and 600mV dropout at 250mA; no enable pin | Targeted at cost-sensitive consumer applications; lacks enable control and thermal shutdown hysteresis | Choose for non-safety-critical, low-cost designs where accuracy and protection features are secondary |
Compared with TLV70733PDQNR and MCP1700T-3302E/TT, LP2981IM5X-3.3/NOPB delivers superior PSRR and tighter accuracy for noise-sensitive industrial monitoring, while maintaining robust thermal protection and enable functionality essential for grid-edge equipment.
Availability
LP2981IM5X-3.3/NOPB is available at Aetrix Electronics and suitable for electricity meters, micro inverters, and residential breakers requiring stable component supply, long-term industrial lifecycle support, and guaranteed traceability.
Supply support for LP2981IM5X-3.3/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 delivering analog and embedded processing solutions, with deep expertise in power management ICs for industrial, automotive, and energy infrastructure markets.
The LP2981-N product line was designed specifically for high-reliability, wide-temperature LDO regulation in utility-grade metering and distributed energy systems - emphasizing accuracy, PSRR, and thermal resilience over ultra-low IQ.
FAQ
What is the minimum input voltage required for LP2981IM5X-3.3/NOPB to regulate 3.3V at 100mA?
The LP2981IM5X-3.3/NOPB requires a minimum input voltage of 3.475V to maintain regulation at 100mA load, based on its maximum dropout voltage of 175mV. At lighter loads, dropout decreases - e.g., 14mV at 1mA - allowing operation closer to 3.3V. Input must also exceed the 2.2V UVLO threshold for startup.
Can LP2981IM5X-3.3/NOPB operate with a 2.2µF ceramic output capacitor?
Yes, LP2981IM5X-3.3/NOPB is explicitly characterized and stabilized with a 2.2µF ceramic output capacitor (X5R/X7R, 10V rating), per TI's Electrical Characteristics table and Figure 5-30. This eliminates ESR dependency and simplifies layout versus older LDOs requiring tantalum or aluminum electrolytics.
Does LP2981IM5X-3.3/NOPB include thermal shutdown protection?
Yes, LP2981IM5X-3.3/NOPB includes thermal shutdown that activates at 170°C junction temperature and resets at 150°C, providing 20°C hysteresis. This protects the device during sustained overload or poor PCB thermal design, and is documented in Section 5.5 (Tsd+ and Tsd– parameters) and Figure 5-36.
What is the shutdown current specification for LP2981IM5X-3.3/NOPB?
The shutdown current for LP2981IM5X-3.3/NOPB is ≤1.75μA at TJ = –40°C to +125°C, measured with VON/OFF < 0.15V and VIN = 16V. This value is specified in Section 5.5 (IGND parameter, "VON/OFF < 0.15 V" condition) and distinguishes the "new chip" revision from legacy versions.
Is pin 4 (NC) on LP2981IM5X-3.3/NOPB safe to connect to ground or leave unconnected?
Pin 4 on LP2981IM5X-3.3/NOPB is designated NC (no connect) and must remain floating - it is reserved for factory calibration and test. Connecting it to ground, VOUT, or any potential risks activating internal trim circuitry and forcing VOUT out of tolerance. TI explicitly prohibits continuity testing or any external connection to this pin.
LP2981IM5X-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 16V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.37V @ 100mA
- Current - Output:
- 100mA
- Current - Quiescent (Iq):
- 95 µA
- Current - Supply (Max):
- 1.7 mA
- PSRR:
- 63dB (1kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature, Short Circuit
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LP2981IM5X-3.3/NOPB FAQ
1.How can I place an order for LP2981IM5X-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP2981IM5X-3.3/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 LP2981IM5X-3.3/NOPB reliable?
The price and inventory of LP2981IM5X-3.3/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP2981IM5X-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LP2981IM5X-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP2981IM5X-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP2981IM5X-3.3/NOPB?
LP2981IM5X-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP2981IM5X-3.3/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 LP2981IM5X-3.3/NOPB?
For technical support, including LP2981IM5X-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP2981IM5X-3.3/NOPB requirements.
6.How does Aetrix verify that LP2981IM5X-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LP2981IM5X-3.3/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 LP2981IM5X-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LP2981IM5X-3.3/NOPB?
All LP2981IM5X-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP2981IM5X-3.3/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 LP2981IM5X-3.3/NOPB part is unused and in its original packaging.
Return procedure for LP2981IM5X-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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