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Diodes Incorporated AP139-28WL-7
- Part No.:
- AP139-28WL-7
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP139-28WL-7.pdf
- Description:
- IC REG LINEAR 2.8V 300MA SOT25
- Quantity:
- Payment:
- Shipping:
Inventory:5,418
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Product details
Overview
AP139-28WL-7 from Diodes Incorporated is a 2.8V, 300mA low-noise CMOS LDO regulator in SOT25 package, featuring 45μA typical quiescent current, 0.45V max dropout at 300mA, ±2% output voltage accuracy, and integrated thermal shutdown/current limiting-designed for battery-powered portable electronics requiring stable low-power regulation.
For engineers reviewing the AP139-28WL-7 datasheet, AP139-28WL-7 pinout, AP139-28WL-7 application, or AP139-28WL-7 equivalent, key selection criteria include dropout performance at full load, bypass capacitor dependency for noise suppression, EN pin logic polarity and leakage, stability with 1.0μF low-ESR output capacitors, and thermal derating in SOT25 under sustained 300mA operation.
Technical Context
The AP139-28WL-7 employs a pMOS pass transistor architecture with internal voltage reference (50ppm/°C), error amplifier, and dual protection circuits: current limit activation at ≥300mA and thermal shutdown at +130°C junction temperature with +20°C hysteresis. It operates exclusively in linear mode-no switching elements or frequency control.
Regulation relies on feedback via internal resistor divider (R1/R2) referenced to VREF; the BYP pin connects to an external 10nF capacitor to reduce reference noise and improve PSRR-especially critical at 1kHz–100kHz where PSRR reaches 75dB (1kHz, 10nF bypass) and drops to 30dB (100kHz). EN pin enables true shutdown with <2.0μA standby current when pulled low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.8V ±2% at 1mA, enabling direct replacement of 2.8V rail without external resistors |
| Max Output Current | Guaranteed 300mA continuous, with current limiting activating at 300–450mA to prevent damage |
| Dropout Voltage | ≤0.45V at 300mA load, allowing operation down to VIN = 3.25V while maintaining regulation |
| Quiescent Current | 45μA typ (60μA max), minimizing battery drain in always-on subsystems |
| PSRR @ 1kHz | 75dB with 10nF BYP capacitor, suppressing ripple from noisy DC-DC stages feeding VIN |
| Thermal Shutdown | Triggers at TJ = +130°C, auto-recovering at +110°C-critical for compact SOT25 layouts without heatsinking |
| Input Voltage Range | 2.7V to 5.5V, compatible with single-cell Li-ion (3.0–4.2V), LiFePO₄, or 3.3V/5V system rails |
Pinout & Package
SOT25 (5-pin, lead-free, RoHS-compliant, "Green" halogen/antimony-free) package with 1.6mm × 2.9mm footprint and 1.1mm height-optimized for space-constrained handheld PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Input power supply connection | Accepts 2.7–5.5V; requires ≥0.1μF ceramic input capacitor near pin for stability |
| GND (Pin 2) | Power ground reference | Low-impedance return path for all internal circuits; must connect to quiet analog ground plane |
| EN (Pin 3) | Active-low enable control | Pulled high internally; drives <0.1μA leakage when floating; <2μA quiescent in shutdown state |
| BYP (Pin 4) | Bypass capacitor terminal | Connects to 10nF capacitor to GND to stabilize internal reference and boost PSRR below 100kHz |
| VOUT (Pin 5) | Regulated output | Delivers 2.8V ±2% into 1.0μF+ low-ESR ceramic output capacitor; stable with ESR up to ~1Ω |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 45μA typ ensures >1-year battery life in 10μA-system standby with coin-cell sources |
| Low-noise regulation | 10nF BYP capacitor reduces reference noise, enabling clean power for RF ICs and ADCs |
| Robust thermal protection | +130°C shutdown with +20°C hysteresis prevents latch-up during transient overloads in sealed enclosures |
| Wide input compatibility | 2.7–5.5V range supports legacy 3.3V rails and modern single-cell batteries without pre-regulation |
| Small-footprint packaging | SOT25 footprint (1.6×2.9mm) fits within 3×3mm board area-ideal for wearables and IoT sensors |
Applications
| Wireless Headsets | Smart Wearables |
|---|---|
|
Use Scenario: Powering Bluetooth audio SoC and MEMS microphone in compact earbud PCBs with limited thermal mass. IC Role / Device Role: Primary 2.8V LDO supplying codec and RF section, enabled only during active streaming. Use Value: 45μA IQ extends talk time by >15% vs. standard LDOs; 0.45V dropout preserves runtime as battery discharges to 3.25V. |
Use Scenario: Regulating 2.8V rail for optical heart-rate sensor and ultra-low-power MCU in wrist-worn fitness tracker. IC Role / Device Role: Always-on LDO powering sensor interface and RTC, with EN controlled by MCU sleep/wake state. Use Value: Thermal shutdown prevents overheating during GPS+HRM concurrent operation in sealed plastic housing. |
| USB-C Peripheral Hubs | Portable Medical Sensors |
|
Use Scenario: Providing clean 2.8V supply to USB PD controller and level-shifting logic in compact dongle form factor. IC Role / Device Role: Secondary LDO decoupling noisy 3.3V USB bus-derived rail before sensitive digital interfaces. Use Value: 75dB PSRR at 1kHz suppresses switching noise from upstream DC-DC converter, reducing data errors. |
Use Scenario: Powering clinical-grade pulse oximeter LED driver and analog front-end in handheld diagnostic device. IC Role / Device Role: Precision LDO delivering stable 2.8V to current-source LED drivers and low-noise amplifiers. Use Value: ±2% output accuracy and 50ppm/°C drift ensure consistent LED intensity and ADC reference stability across -20°C to +70°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7343-28W5G-7 | Successor part: 40μA IQ, 0.35V dropout @300mA, improved PSRR (80dB @1kHz), same SOT25 package | Pin-compatible drop-in replacement; supports higher ambient temps (TJ up to +150°C) and tighter load regulation (±0.5%) | Select for new designs requiring extended lifetime, lower dropout, or AEC-Q200 qualification support |
| MCP1700-2802E/TO | Microchip 2.8V LDO in TO-92: 2.0μA IQ, 100mA rated, 6V max VIN, no BYP pin or thermal shutdown | Limited to ultra-low-power (<100mA), non-thermal-critical applications; lacks enable and bypass functionality | Use only where cost sensitivity outweighs performance needs and thermal safety is externally managed |
Compared with AP139-28WL-7, AP7343-28W5G-7 delivers measurable improvements in efficiency and reliability for production designs, while MCP1700-2802E/TO serves niche ultra-low-IQ roles but sacrifices current capability, protection, and noise performance.
Availability
AP139-28WL-7 is available at Aetrix Electronics and suitable for battery-powered portable electronics, USB peripheral power management, and medical sensor modules requiring stable component supply with known end-of-life status.
Supply support for AP139-28WL-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.
The AP139 belongs to Diodes' low-noise CMOS LDO product line, engineered specifically for energy-constrained portable devices where battery life, thermal safety, and small size are primary design constraints.
FAQ
What is the minimum input voltage required for AP139-28WL-7 to maintain 2.8V output at 300mA?
The minimum input voltage is calculated as VOUT + VDROPOUT = 2.8V + 0.45V = 3.25V. Below this, regulation fails and VOUT drops linearly with VIN. At lighter loads (e.g., 10mA), dropout falls to <0.1V, allowing operation down to ~2.85V.
Can AP139-28WL-7 operate without the 10nF bypass capacitor on the BYP pin?
No-omitting the 10nF BYP capacitor degrades PSRR by up to 25dB at 1kHz and increases output noise significantly. The internal reference requires this capacitor for stability; operation without it may cause erratic regulation or increased ripple in noise-sensitive circuits.
Is AP139-28WL-7 pin-compatible with AP7343-28W5G-7?
Yes-both use identical SOT25 pinout (VIN, GND, EN, BYP, VOUT), same footprint, and share identical enable logic and capacitor requirements. AP7343-28W5G-7 is a direct functional upgrade with improved specs and ongoing production support.
Why does the datasheet state "NOT RECOMMENDED FOR NEW DESIGNS"?
Diodes has designated AP139-28WL-7 as NRND (Not Recommended for New Designs) due to introduction of the superior AP7343 series. While fully functional and supported for existing designs, new projects should adopt AP7343-28W5G-7 for longer-term supply assurance and enhanced performance.
AP139-28WL-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- 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):
- 5.5V
- Voltage - Output (Min/Fixed):
- 2.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.45V @ 300mA
- Current - Output:
- 300mA
- Current - Quiescent (Iq):
- 60 µA
- Current - Supply (Max):
- -
- PSRR:
- 75dB ~ 30dB (1KHz ~ 100KHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature, Short Circuit
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-25
AP139-28WL-7 FAQ
1.How can I place an order for AP139-28WL-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP139-28WL-7 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 AP139-28WL-7 reliable?
The price and inventory of AP139-28WL-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP139-28WL-7 is usually 5 days.
3.What payment methods are accepted for AP139-28WL-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP139-28WL-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP139-28WL-7?
AP139-28WL-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP139-28WL-7 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 AP139-28WL-7?
For technical support, including AP139-28WL-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP139-28WL-7 requirements.
6.How does Aetrix verify that AP139-28WL-7 is sourced from the original manufacturer or authorized distributors?
All AP139-28WL-7 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 AP139-28WL-7 meets industry standards.
7.What is the process for return or replacement of AP139-28WL-7?
All AP139-28WL-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP139-28WL-7, 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 AP139-28WL-7 part is unused and in its original packaging.
Return procedure for AP139-28WL-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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