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Texas Instruments LP2981IM5X-5.0/NOPB
- Part No.:
- LP2981IM5X-5.0/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LP2981IM5X-5.0/NOPB.pdf
- Description:
- IC REG LINEAR 5V 100MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,418
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Product details
Overview
LP2981IM5X-5.0/NOPB from Texas Instruments is a fixed 5.0V, 100mA low-dropout (LDO) voltage regulator in SOT-23-5 package, designed for post-regulation of DC/DC converters in space-constrained industrial and metering systems. It delivers ±0.5% output accuracy over load and temperature, 175mV dropout at 100mA, and 75dB PSRR at 1kHz - enabling stable power for low-voltage MCUs in electricity meters and micro-inverters.
For engineers reviewing the LP2981IM5X-5.0/NOPB datasheet, LP2981IM5X-5.0/NOPB pinout, LP2981IM5X-5.0/NOPB application, or LP2981IM5X-5.0/NOPB equivalent, key selection criteria include input range (2.5V–16V), shutdown current (≤1.75μA), soft-start behavior, stability with 2.2µF ceramic output capacitors, and thermal shutdown at 170°C.
Technical Context
The LP2981IM5X-5.0/NOPB implements a CMOS-based LDO architecture with internal bandgap reference (1.2V), UVLO (2.2V rising threshold), and active-high enable logic. Its pass transistor operates in ohmic region with RDS(ON) ≈ 1.75Ω (calculated from 175mV/100mA), enabling low dropout across temperature.
It integrates overcurrent protection (150mA short-circuit limit), thermal shutdown (170°C trip, 150°C reset), internal output pulldown during disable, and soft-start to limit inrush current - eliminating need for external sequencing components in battery-backed or hot-swap applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±0.5% (A-grade & standard grade), ensuring compatibility with 5V-tolerant MCU I/O and analog peripherals. |
| Max Output Current | 100mA continuous - sufficient for powering core logic, sensors, and communication interfaces in smart meters and breakers. |
| Dropout Voltage | 175mV at 100mA and 125°C - enables regulation from 5.175V input, supporting wide-input DC/DC front-ends. |
| PSRR | 75dB at 1kHz, 45dB at 1MHz - effectively suppresses switching noise from upstream buck converters without added LC filtering. |
| Quiescent Current | 69μA at zero load, 620μA at 100mA - balances ultra-low standby power with dynamic efficiency in always-on monitoring systems. |
| Operating Temp | –40°C to +125°C junction - validated for deployment in outdoor electricity meters and industrial breaker enclosures. |
| Shutdown Current | ≤1.75μA over temperature - preserves battery life in backup-supplied metering subsystems during mains failure. |
Pinout & Package
Package: 5-pin SOT-23 (DBV), 2.9mm × 2.8mm footprint, surface-mount compatible with standard reflow profiles.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (IN) | Input supply | Accepts 2.5V–16V; requires ≥1µF ceramic capacitor to GND for stability and transient response. |
| 2 (GND) | Ground reference | Common substrate return for all internal circuits; must be low-impedance connection to system ground plane. |
| 3 (ON/OFF) | Enable control | Active-high logic: >0.85V enables regulator; <0.15V disables it with internal pulldown to discharge VOUT. |
| 4 (NC) | No-connect | Reserved for factory calibration; must remain floating - no PCB trace, no test probe, no grounding. |
| 5 (OUT) | Regulated output | Delivers 5.0V; 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, size, and aging-related failure risk. |
| Internal soft-start | Controls inrush current during power-up, minimizing stress on input capacitors and upstream DC/DC converters. |
| Output pulldown during disable | Actively discharges VOUT when disabled - prevents floating rail issues and ensures predictable reset behavior. |
| UVLO with hysteresis | 2.2V rising / 1.9V falling threshold (0.13V hysteresis) prevents oscillation near brownout conditions. |
| Thermal shutdown with hysteresis | Shuts down at 170°C, resets at 150°C - protects against sustained overload or poor heatsinking in sealed enclosures. |
Applications
| Electricity Meters | Micro Inverters |
|---|---|
|
Use Scenario: Powering metrology ASIC, RTC, and isolated communication interface in Class 0.2 revenue-grade meters. IC Role / Device Role / Timing Role: Post-regulator supplying clean 5.0V to precision ADC reference and SPI peripherals. Use Value: ±0.5% output accuracy and 75dB PSRR maintain measurement integrity despite noisy DC bus ripple. |
Use Scenario: Biasing gate drivers and sensing circuitry in single-phase solar micro-inverters operating at 125°C ambient. IC Role / Device Role / Timing Role: Local 5.0V LDO for isolated gate driver ICs and current-sense amplifiers. Use Value: 125°C max junction rating and thermal shutdown ensure reliability under sustained partial shading conditions. |
| Server PSU Monitoring | Residential Circuit Breakers |
|
Use Scenario: Supplying 5.0V to PMBus/I²C monitoring ICs and fault-reporting logic in 12V-output server PSUs. IC Role / Device Role / Timing Role: Secondary regulator decoupling digital monitoring circuitry from high-current 12V rail. Use Value: 45dB PSRR at 1MHz attenuates high-frequency switching noise from primary-side controllers. |
Use Scenario: Powering arc-fault detection DSP and wireless BLE module in DIN-rail mounted smart breakers. IC Role / Device Role / Timing Role: Always-on 5.0V source enabling rapid wake-from-sleep response to fault events. Use Value: 69μA quiescent current and ≤1.75μA shutdown current extend battery backup runtime during grid outages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV70750PDQNR | Lower IQ (25μA), lower dropout (170mV @100mA), but only rated to 125°C TJ and lacks internal pulldown. | Suitable for consumer-grade portable devices; not qualified for extended-temperature industrial metering. | Prefer LP2981IM5X-5.0/NOPB where 125°C operation, pulldown, or UVLO hysteresis are required. |
| MCP1703T-5002E/MB | Higher dropout (330mV @100mA), wider input (2.3V–16V), ±2% accuracy, no enable pin. | Fits cost-sensitive designs without enable control or tight accuracy requirements. | Choose LP2981IM5X-5.0/NOPB when precise 5.0V, enable functionality, or superior PSRR is critical. |
Compared with TLV70750PDQNR and MCP1703T-5002E/MB, the LP2981IM5X-5.0/NOPB provides tighter output accuracy (±0.5%), integrated enable with pulldown, and higher temperature rating - making it optimal for industrial metering and breaker applications demanding long-term stability and robust fault handling.
Availability
LP2981IM5X-5.0/NOPB is available at Aetrix Electronics and suitable for electricity meters, micro inverters, and residential breakers requiring stable component supply, extended temperature operation, and long-lifecycle support.
Supply support for LP2981IM5X-5.0/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 decades of expertise in power management ICs for industrial, automotive, and energy infrastructure markets.
The LP2981-N product line was engineered specifically for high-accuracy, low-noise post-regulation in utility-grade metering and distributed energy systems - emphasizing thermal robustness, PSRR performance, and factory-trimmed voltage tolerance.
FAQ
What is the input voltage range supported by the LP2981IM5X-5.0/NOPB?
The LP2981IM5X-5.0/NOPB supports an input voltage range of 2.5V to 16V, as specified for the "new chip" variant in the official TI datasheet SNOS773P. This range enables use after 3.3V, 5V, or 12V DC/DC converters while maintaining regulation down to 2.5V input - critical for brownout resilience in electricity meters.
Does the LP2981IM5X-5.0/NOPB require an external pull-up on the ON/OFF pin?
No - the LP2981IM5X-5.0/NOPB does not require an external pull-up. When unused, the ON/OFF pin may be tied directly to VIN to enable the device continuously. The part includes internal circuitry that actively pulls the output low during disable, and the ON/OFF pin has defined high/low thresholds (0.85V/0.15V) for reliable logic-level interfacing.
Can the LP2981IM5X-5.0/NOPB operate stably with a 1µF output capacitor?
No - the LP2981IM5X-5.0/NOPB requires a minimum 2.2µF ceramic output capacitor for guaranteed stability and PSRR performance, per Section 5.3 of the datasheet. While the nominal minimum is stated as 1µF (derated to 50%), TI validates stability and transient response only with ≥2.2µF X7R/X5R ceramics.
What is the thermal shutdown behavior of the LP2981IM5X-5.0/NOPB?
The LP2981IM5X-5.0/NOPB activates thermal shutdown at 170°C junction temperature and resets at 150°C, providing 20°C hysteresis to prevent cycling. This behavior is confirmed in Section 5.5 Electrical Characteristics and applies specifically to the "new chip" variant - the version embodied by LP2981IM5X-5.0/NOPB.
Is pin 4 (NC) on the LP2981IM5X-5.0/NOPB safe to leave unconnected on the PCB?
Yes - pin 4 is designated NC (no-connect) and must remain floating with no PCB trace, solder mask opening, or test point. It is reserved for post-package calibration and connecting it to any potential - including GND - risks activating internal trim circuitry and shifting VOUT outside tolerance. TI explicitly prohibits continuity testing on this pin.
LP2981IM5X-5.0/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):
- 5V
- 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-5.0/NOPB FAQ
1.How can I place an order for LP2981IM5X-5.0/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP2981IM5X-5.0/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-5.0/NOPB reliable?
The price and inventory of LP2981IM5X-5.0/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-5.0/NOPB is usually 5 days.
3.What payment methods are accepted for LP2981IM5X-5.0/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP2981IM5X-5.0/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP2981IM5X-5.0/NOPB?
LP2981IM5X-5.0/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP2981IM5X-5.0/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-5.0/NOPB?
For technical support, including LP2981IM5X-5.0/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP2981IM5X-5.0/NOPB requirements.
6.How does Aetrix verify that LP2981IM5X-5.0/NOPB is sourced from the original manufacturer or authorized distributors?
All LP2981IM5X-5.0/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-5.0/NOPB meets industry standards.
7.What is the process for return or replacement of LP2981IM5X-5.0/NOPB?
All LP2981IM5X-5.0/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP2981IM5X-5.0/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-5.0/NOPB part is unused and in its original packaging.
Return procedure for LP2981IM5X-5.0/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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