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Texas Instruments LP38691DTX-2.5/NOPB
- Part No.:
- LP38691DTX-2.5/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LP38691DTX-2.5/NOPB.pdf
- Description:
- IC REG LINEAR 2.5V 500MA TO252-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,508
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Product details
Overview
LP38691DTX-2.5/NOPB from Texas Instruments is a 500-mA, 2.5-V fixed-output low-dropout CMOS linear regulator in WSON-6 package, featuring 250 mV dropout at 500 mA (VOUT = 5 V), ±2% output accuracy over –40°C to 125°C, and stable operation with only 1-µF ceramic output capacitor. It serves as a primary voltage rail for microcontroller cores and memory subsystems in space-constrained portable electronics.
For engineers reviewing the LP38691DTX-2.5/NOPB datasheet, LP38691DTX-2.5/NOPB pinout, LP38691DTX-2.5/NOPB application, or LP38691DTX-2.5/NOPB equivalent, key selection considerations include dropout performance at 2.5 V output, thermal behavior in WSON-6 under 500-mA load, remote sense capability (SNS pin), ground current <100 µA across temperature, and compatibility with ultra-low-ESR ceramic capacitors without external compensation.
Technical Context
The LP38691DTX-2.5/NOPB employs a PMOS pass transistor architecture eliminating DC base-drive current, enabling ground pin current of just 55 µA at full load regardless of input voltage or temperature. Its trimmed bandgap reference and internal feedback network deliver 2% initial output tolerance and ensure regulation stability from 2.7 V to 10 V input across –40°C to 125°C.
No enable pin is integrated - unlike the LP38693 variant - making it a simple ON/OFF device controlled solely by input voltage presence. The SNS pin supports remote voltage sensing exclusively in WSON packages, correcting for PCB trace IR drop between regulator and load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.5 V ±2% (ensured over –40°C to 125°C) |
| Max Output Current | 500 mA (full rated current with proper thermal layout on PCB) |
| Dropout Voltage | 250 mV typical at 500 mA (enables operation down to VIN = 2.75 V) |
| Input Voltage Range | 2.7 V to 10 V (no UVLO; regulation begins only when VIN ≥ VOUT + VDO) |
| Ground Current | 55 µA typical at full load (enables high efficiency in battery-powered standby modes) |
| Output Capacitor | Stable with ≥1 µF ceramic (no ESR requirement; eliminates need for tantalum) |
| PSRR | 55 dB at 120 Hz (supports clean power for ADCs and RF receivers) |
Pinout & Package
LP38691DTX-2.5/NOPB uses the NGG (WSON-6) package: 3.00 mm × 3.00 mm body with exposed thermal pad (DAP) on bottom for enhanced heat dissipation. Pin 1 = IN, Pin 2 = GND, Pin 3 = OUT, Pin 4 = IN (dual-input configuration), Pin 5 = SNS, Pin 6 = NC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pins 1 & 4) | Input supply connection | Both pins must be tied together externally; each rated for ≤250 mA to support full 500-mA operation |
| GND (Pin 2) | Power and signal reference | Thermally connected to die; requires soldering DAP to large copper plane for thermal management |
| OUT (Pin 3) | Regulated output node | Delivers 2.5 V to load; connects directly to SNS for local sensing or via trace to remote point |
| SNS (Pin 5) | Remote output voltage sense | Compensates for PCB trace resistance drop; must be connected to load-side of output trace, not to OUT pin |
| NC (Pin 6) | No internal connection | Not bonded; left unconnected or grounded per layout best practice (no functional impact) |
Key Features
| Feature | Design Value |
|---|---|
| PMOS pass transistor | Eliminates base-drive current, keeping ground pin current ≤100 µA across all loads/temperatures |
| Trimmed bandgap reference | Enables ±2% output accuracy over full industrial temperature range without external trimming |
| Thermal shutdown | Activates at ~160°C junction temp with 10°C hysteresis, protecting against sustained overload |
| Foldback current limiting | Reduces output current as VIN–VOUT drops below 4 V (e.g., 850 mA limit at 4 V differential) |
| Ultra-low-noise operation | 0.7 µV/√Hz output noise (at 3.3 V); confirmed for 2.5 V via proportional scaling in same family |
Applications
| Hard Disk Drive Power Rails | Notebook System Core Voltage |
|---|---|
Use Scenario: Supplies 2.5-V logic voltage to HDD controller ASIC and buffer memory during active read/write cycles. IC Role / Device Role / Timing Role: Primary LDO delivering tightly regulated, low-noise 2.5-V rail with fast line/load transient response. Use Value: Enables reliable data integrity by maintaining <±2% output under 500-mA dynamic load steps and rejecting 120-Hz ripple from upstream switching converters. | Use Scenario: Powers CPU I/O interface and chipset southbridge logic in ultraportable notebooks with strict thermal envelope. IC Role / Device Role / Timing Role: Fixed-output LDO providing stable 2.5-V supply independent of battery voltage sag. Use Value: Delivers full 500-mA current with only 250-mV dropout, extending usable battery life down to 2.75-V cell voltage while maintaining thermal safety in WSON-6. |
| Battery-Powered Medical Sensors | Industrial PLC I/O Modules |
Use Scenario: Powers precision analog front-end (AFE) and low-power MCU in handheld glucose meters and pulse oximeters. IC Role / Device Role / Timing Role: Low-quiescent-current LDO supplying clean 2.5-V reference and core logic voltage. Use Value: 55-µA ground current at full load and 0.7-µV/√Hz noise ensure sub-16-bit ADC accuracy and >100-hour battery life on coin-cell sources. | Use Scenario: Provides isolated 2.5-V auxiliary rail for digital isolator biasing and optocoupler LED drivers in DIN-rail mounted controllers. IC Role / Device Role / Timing Role: Robust LDO operating across –40°C to 125°C ambient with thermal foldback protection. Use Value: Ensured ±2% output tolerance and thermal shutdown at 160°C enable reliable operation in unventilated enclosures with no derating required up to 85°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPL7407LPGQ | 7-channel high-side driver with integrated 2.5-V LDO; not a standalone regulator | Designed for LED/display driver integration, not discrete rail generation | Select only if system requires co-located driver + LDO functionality; not a direct replacement |
| TPS7A2025PDQNR | 2.5-V, 300-mA LDO in X2SON-4; 160-mV dropout at 300 mA; no SNS pin | Limited current and no remote sensing; optimized for ultra-small footprint, not high-current stability | Choose for space-constrained designs needing <300 mA; LP38691DTX-2.5/NOPB remains preferred for 500-mA + SNS capability |
Compared with TPL7407LPGQ and TPS7A2025PDQNR, LP38691DTX-2.5/NOPB uniquely combines 500-mA output, remote sensing (SNS), and WSON-6 thermal performance - making it the only option among the three qualified for high-current, precision-sensing applications like HDD and industrial PLC rails.
Availability
LP38691DTX-2.5/NOPB is available at Aetrix Electronics and suitable for hard disk drives, notebook computers, and battery-powered medical sensors requiring stable component supply with guaranteed long-term manufacturability and automotive-grade reliability options (LP38691-Q1).
Supply support for LP38691DTX-2.5/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 designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and consumer markets.
The LP3869x product line delivers low-dropout linear regulators optimized for portable, battery-powered digital systems requiring fast start-up, tight output tolerance, and ceramic-capacitor stability - with variants supporting automotive AEC-Q100 Grade 1 qualification.
FAQ
What is the minimum input voltage required for LP38691DTX-2.5/NOPB to regulate at 2.5 V?
The LP38691DTX-2.5/NOPB requires VIN ≥ VOUT + VDO to maintain regulation. With a typical dropout voltage of 250 mV at 500 mA, the minimum functional input is 2.75 V. However, the absolute minimum specified input is 2.7 V - below which internal circuitry may not power up reliably. Regulation is not ensured until VIN reaches at least 2.75 V under full load.
Does LP38691DTX-2.5/NOPB include an enable (EN) pin?
No, LP38691DTX-2.5/NOPB does not have an enable pin. It is always active when valid input voltage is applied. The EN pin is exclusive to the LP38693 variant. For on/off control of LP38691DTX-2.5/NOPB, external switching of the input rail or use of a series MOSFET is required.
Can LP38691DTX-2.5/NOPB operate with a 1-µF output capacitor as stated in the datasheet?
Yes - LP38691DTX-2.5/NOPB is specifically designed to be stable with a single 1-µF ceramic output capacitor, with no ESR requirement. This eliminates the need for larger, higher-ESR tantalum or aluminum electrolytic capacitors. The 1-µF value is the minimum required for stability; increasing capacitance improves transient response without compromising stability.
What is the function of the SNS pin on LP38691DTX-2.5/NOPB, and how should it be connected?
The SNS (sense) pin on LP38691DTX-2.5/NOPB enables remote output voltage sensing to compensate for IR drop in PCB traces. It must be connected directly to the load-side of the output trace - not to the OUT pin - to measure voltage at the point of load. If local regulation is sufficient, SNS may be tied directly to OUT. Leaving SNS floating is not permitted and will cause regulation failure.
Is LP38691DTX-2.5/NOPB pin-compatible with other devices in the LP3869x family?
LP38691DTX-2.5/NOPB shares the same NGG (WSON-6) package and pinout with LP38691 variants (e.g., LP38691SD-1.8), but is not pin-compatible with LP38693 due to the EN pin occupying Pin 5 instead of SNS. Substituting LP38691DTX-2.5/NOPB for LP38693 requires PCB layout changes to reroute SNS functionality and remove EN control logic.
LP38691DTX-2.5/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 10V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.73V @ 500mA
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 55 µA
- Current - Supply (Max):
- 100 µA
- PSRR:
- 55dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-252-3
LP38691DTX-2.5/NOPB FAQ
1.How can I place an order for LP38691DTX-2.5/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP38691DTX-2.5/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 LP38691DTX-2.5/NOPB reliable?
The price and inventory of LP38691DTX-2.5/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP38691DTX-2.5/NOPB is usually 5 days.
3.What payment methods are accepted for LP38691DTX-2.5/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP38691DTX-2.5/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP38691DTX-2.5/NOPB?
LP38691DTX-2.5/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP38691DTX-2.5/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 LP38691DTX-2.5/NOPB?
For technical support, including LP38691DTX-2.5/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP38691DTX-2.5/NOPB requirements.
6.How does Aetrix verify that LP38691DTX-2.5/NOPB is sourced from the original manufacturer or authorized distributors?
All LP38691DTX-2.5/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 LP38691DTX-2.5/NOPB meets industry standards.
7.What is the process for return or replacement of LP38691DTX-2.5/NOPB?
All LP38691DTX-2.5/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP38691DTX-2.5/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 LP38691DTX-2.5/NOPB part is unused and in its original packaging.
Return procedure for LP38691DTX-2.5/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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