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Texas Instruments LP3981IMM-2.5
- Part No.:
- LP3981IMM-2.5
- Manufacturer:
- Texas Instruments
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LP3981IMM-2.5.pdf
- Description:
- IC REG LINEAR 2.5V 300MA 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,342
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Product details
Overview
LP3981IMM-2.5 from Texas Instruments is a micropower, ultra-low-dropout CMOS voltage regulator delivering 300 mA at fixed 2.5 V output with ≤132 mV dropout at full load, 35 µVRMS output noise (10 Hz–100 kHz), and 60 dB PSRR at 1 kHz - designed for battery-powered RF and analog subsystems in mobile handsets.
For engineers reviewing the LP3981IMM-2.5 datasheet, LP3981IMM-2.5 pinout, LP3981IMM-2.5 application, or LP3981IMM-2.5 equivalent, key selection criteria include shutdown current (≤1.5 µA), ceramic-capacitor stability (2.2 µF min), thermal performance in WSON-6 (RθJA = 56.5°C/W), and enable logic thresholds (VIL ≤ 0.4 V, VIH ≥ 1.4 V).
Technical Context
The LP3981IMM-2.5 integrates a precision bandgap reference (1.23 V), fast-turnon circuitry, and overcurrent/thermal protection. Its low-noise architecture uses a dedicated BYPASS pin to decouple the internal reference node, enabling 35 µVRMS noise without degrading transient response.
It operates across −40°C to +125°C with input range 2.7 V to 6 V, requiring only 0.3 V headroom above VOUT for regulation. Ground current rises only modestly in dropout - 170 µA at 150 mA - preserving battery life in deep-discharge conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.5 V ±3% over −40°C to +125°C - ensures stable core/sensor rail in wide-temperature portable designs. |
| Max Output Current | 300 mA continuous - sufficient for baseband processors, RF transceivers, or multi-rail PMIC sub-regulation. |
| Dropout Voltage | 132 mV typical at 300 mA - enables operation down to 2.632 V input, extending usable battery range in Li-ion systems. |
| Quiescent Current | 70 µA typical at 1 mA load - minimizes standby power loss in always-on sensor or memory-retention circuits. |
| Shutdown Current | 0.003 µA typical - reduces system leakage to negligible levels during deep sleep modes. |
| PSRR @ 1 kHz | 60 dB - suppresses switching noise from adjacent DC/DC converters feeding the same battery source. |
| Output Noise | 35 µVRMS (10 Hz–100 kHz) with 0.033 µF BYPASS capacitor - meets low-noise requirements for ADC references or RF VCO supplies. |
| Enable Thresholds | VIL ≤ 0.4 V, VIH ≥ 1.4 V - compatible with 1.8-V and 3.3-V GPIO control without level-shifting. |
Pinout & Package
LP3981IMM-2.5 is packaged in a thermally enhanced 6-pin WSON (NGC) package measuring 4.00 mm × 3.00 mm with exposed thermal pad (connected to GND). This package delivers RθJA = 56.5°C/W, enabling high-power-density layouts in space-constrained handhelds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pin 2) | Input voltage supply | Accepts 2.7–6 V; requires 2.2 µF ceramic input capacitor placed ≤1 cm from pin for stability and EMI suppression. |
| EN (Pin 6) | Logic-controlled enable | Active-high digital input; drives device ON when ≥1.4 V, OFF when ≤0.4 V; draws ≤0.001 µA when disabled. |
| BYPASS (Pin 5) | Noise reduction node | Connects to 0.033 µF capacitor to ground; isolates internal reference from noise, reducing output ripple by >20 dB. |
| OUT (Pin 1) | Regulated output | Delivers 2.5 V ±3%; must be connected to OUT-SENSE via short trace or direct bond wire for accurate sensing. |
| OUT-SENSE (Pin 3) | Remote output voltage sense | Feedback path for output regulation; must be tied directly to OUT pin to maintain specified accuracy and stability. |
| GND (Pin 4) | Power and signal ground | Common return for IN, OUT, EN, and BYPASS; thermal pad must be soldered to PCB ground plane for thermal integrity. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low-noise regulation | 35 µVRMS output noise (10 Hz–100 kHz) with optional BYPASS capacitor - eliminates need for post-LDO filtering in sensitive analog rails. |
| Ceramic-capacitor stability | Stable with 2.2–22 µF ceramic output capacitors (5–500 mΩ ESR) - enables smallest footprint, lowest cost, and highest reliability vs. tantalum alternatives. |
| Low-dropout operation | 132 mV dropout at 300 mA load - extends usable battery voltage range by ~150 mV compared to standard LDOs, delaying system shutdown. |
| Thermal robustness | Thermal shutdown at 160°C with 20°C hysteresis and short-circuit current limit of 600 mA - protects against sustained overload in compact enclosures. |
| Fast enable response | 240 µs typical turn-on time (95% of VOUT) with 0.033 µF BYPASS - supports rapid power sequencing in multi-rail SoC applications. |
| Wide temperature support | Specified from −40°C to +125°C junction temperature - qualified for automotive infotainment, industrial handhelds, and extended-life IoT devices. |
Applications
| CDMA Cellular Handset Power Rail | Portable Medical Sensor Supply |
|---|---|
Use Scenario: Powers RF transceiver IC and baseband processor core in CDMA handset operating from single-cell Li-ion (2.8–4.2 V). IC Role / Device Role / Timing Role: Primary low-noise 2.5-V supply for analog front-end and PLL reference clock generation. Use Value: 60 dB PSRR rejects switching noise from buck converter powering digital subsystem; 35 µVRMS noise prevents EVM degradation in 1xRTT transmission. |
Use Scenario: Supplies precision ADC, low-noise op-amp, and microcontroller in battery-operated glucose monitor. IC Role / Device Role / Timing Role: Clean, stable 2.5-V reference rail for 16-bit SAR ADC and analog signal conditioning chain. Use Value: ≤132 mV dropout allows operation until battery reaches 2.63 V; <1.5 µA shutdown current enables multi-month shelf life in unpowered state. |
| GSM Baseband Processor Core | Industrial Wireless Sensor Node |
Use Scenario: Provides regulated 2.5-V supply to GSM baseband ASIC during burst transmission (peak 250 mA). IC Role / Device Role / Timing Role: High-current, low-noise LDO co-located with ASIC to minimize IR drop and noise coupling. Use Value: 300 mA capability handles GSM Class 4 transmit peaks; 170 µA ground current at 150 mA preserves battery runtime during active talk time. |
Use Scenario: Powers LoRa transceiver, MCU, and environmental sensors in solar-charged remote telemetry unit. IC Role / Device Role / Timing Role: Always-on 2.5-V rail for RTC, SRAM retention, and wake-up circuitry during deep-sleep cycles. Use Value: 0.003 µA shutdown current enables >10-year battery life in maintenance-free deployments; no-load stability prevents brownout on wake-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPL7407LPGEDR | 300 mA, 2.5 V fixed, but higher dropout (250 mV @ 300 mA) and higher noise (65 µVRMS); no BYPASS pin. | Lacks ultra-low-noise capability; unsuitable for RF or precision analog where LP3981IMM-2.5's 35 µVRMS is required. | Choose only if board space permits larger input/output caps and noise budget allows >2× LP3981IMM-2.5's noise floor. |
| MCP1703T-2502E/MB | 250 mA max, 2.5 V fixed, 600 mV dropout @ 250 mA, 80 µVRMS noise; SOT-23-5 package. | Lower current and higher dropout limit use in high-load or low-input-voltage scenarios where LP3981IMM-2.5 remains functional. | Select when cost sensitivity outweighs performance needs and thermal constraints allow SOT-23 footprint. |
Compared with TPL7407LPGEDR and MCP1703T-2502E/MB, LP3981IMM-2.5 uniquely combines 300 mA delivery, 132 mV dropout, and 35 µVRMS noise in a thermally optimized WSON package - making it irreplaceable in space- and noise-constrained RF subsystems requiring extended battery life.
Availability
LP3981IMM-2.5 is available at Aetrix Electronics and suitable for CDMA/GSM handset power management, portable medical sensor supplies, industrial wireless nodes, and battery-backed memory retention circuits requiring stable component supply across long production lifecycles.
Supply support for LP3981IMM-2.5 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 focused on analog, embedded processing, and connectivity technologies, serving industrial, automotive, and consumer markets with high-reliability silicon solutions.
The LP3981IMM-2.5 belongs to TI's micropower LDO family engineered specifically for ultra-low-noise, ultra-low-dropout regulation in battery-powered wireless and portable electronics - emphasizing quiescent current optimization, ceramic-capacitor compatibility, and thermal resilience.
FAQ
What is the minimum input voltage required for LP3981IMM-2.5 to regulate at 2.5 V?
The LP3981IMM-2.5 requires VIN ≥ VOUT + 0.3 V for proper regulation, meaning minimum input is 2.8 V under recommended conditions. At 300 mA load, dropout is 132 mV, so regulation is maintained down to 2.632 V input - verified across −40°C to +125°C per Electrical Characteristics table.
Can LP3981IMM-2.5 operate without the BYPASS capacitor?
Yes, LP3981IMM-2.5 functions without the BYPASS capacitor but with higher output noise: 35 µVRMS requires the 0.033 µF capacitor on the BYPASS pin. Omitting it increases noise to ~120 µVRMS, as confirmed in Typical Characteristics Figure 6–8 and Feature Description section 8.3.6.
Is LP3981IMM-2.5 stable with a 2.2 µF ceramic output capacitor?
Yes - LP3981IMM-2.5 is explicitly characterized and guaranteed stable with 2.2 µF ceramic output capacitors (X7R/Z5U/Y5V dielectrics) having 5–500 mΩ ESR, per Section 9.2.2.4 and Electrical Characteristics table. No additional series resistance or damping is needed.
What is the thermal pad connection requirement for LP3981IMM-2.5?
The exposed thermal pad on the LP3981IMM-2.5 WSON package must be soldered to a PCB ground plane. Per Pin Descriptions and Layout Guidelines, it serves as both thermal conduction path and electrical GND connection - not connecting it degrades RθJA from 56.5°C/W to >100°C/W and risks thermal shutdown.
Does LP3981IMM-2.5 support remote sensing, and how is it implemented?
Yes - LP3981IMM-2.5 implements remote sensing via the OUT-SENSE pin (Pin 3), which must be connected directly to the OUT pin (Pin 1) using a low-impedance trace or bond wire. This configuration compensates for PCB trace IR drop and maintains ±3% output accuracy under load, as defined in Pin Descriptions and Functional Block Diagram.
LP3981IMM-2.5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 6V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.2V @ 300mA
- Current - Output:
- 300mA
- Current - Quiescent (Iq):
- 120 µA
- Current - Supply (Max):
- 210 µA
- PSRR:
- 50dB ~ 55dB (1kHz ~ 10kHz)
- 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:
- 8-VSSOP
LP3981IMM-2.5 FAQ
1.How can I place an order for LP3981IMM-2.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3981IMM-2.5 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 LP3981IMM-2.5 reliable?
The price and inventory of LP3981IMM-2.5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP3981IMM-2.5 is usually 5 days.
3.What payment methods are accepted for LP3981IMM-2.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3981IMM-2.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3981IMM-2.5?
LP3981IMM-2.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3981IMM-2.5 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 LP3981IMM-2.5?
For technical support, including LP3981IMM-2.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3981IMM-2.5 requirements.
6.How does Aetrix verify that LP3981IMM-2.5 is sourced from the original manufacturer or authorized distributors?
All LP3981IMM-2.5 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 LP3981IMM-2.5 meets industry standards.
7.What is the process for return or replacement of LP3981IMM-2.5?
All LP3981IMM-2.5 units undergo pre-shipment inspection (PSI). If there is an issue with LP3981IMM-2.5, 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 LP3981IMM-2.5 part is unused and in its original packaging.
Return procedure for LP3981IMM-2.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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