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Diodes Incorporated AP139-28WG-7
- Part No.:
- AP139-28WG-7
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP139-28WG-7.pdf
- Description:
- IC REG LINEAR 2.8V 300MA SOT25
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
AP139-28WG-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 biasing.
For engineers reviewing the AP139-28WG-7 datasheet, AP139-28WG-7 pinout, AP139-28WG-7 application, or AP139-28WG-7 equivalent, key selection criteria include dropout performance at 300mA load, bypass capacitor dependency (10nF required), stability with ≥1.0μF low-ESR output capacitors, and EN pin logic behavior (active-low enable with <0.1μA leakage).
Technical Context
The AP139-28WG-7 employs a pMOS pass transistor architecture with internal voltage reference and error amplifier feedback, enabling precise regulation across input voltages from 2.7V to 5.5V. Its low-quiescent-current design (45μA typ) and thermal foldback protection activate at +130°C junction temperature with +20°C hysteresis.
Operation requires external 10nF bypass capacitor between BYP and GND to achieve low-noise performance; PSRR reaches 75dB at 1kHz with 10nF BYP cap. The device transitions from voltage-mode to current-mode regulation when load exceeds 300mA, limiting output to 450mA max under overcurrent conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.8V ±2% at 1mA–300mA load, ensuring stable rail for 2.8V logic or analog circuitry. |
| Max Output Current | Guaranteed 300mA continuous; current limit activates at 300–450mA to prevent damage. |
| Dropout Voltage | ≤0.45V at 300mA (VOUT ≥ 2.8V), enabling operation down to VIN = 3.25V. |
| Quiescent Current | 45μA typical, 60μA max-critical for multi-day battery life in always-on sensors. |
| PSRR @ 1kHz | 75dB with 10nF BYP cap, suppressing ripple from noisy switching supplies. |
| Thermal Shutdown | Activates at TJ = +130°C; resumes operation after cooling to +110°C (20°C hysteresis). |
| Input Voltage Range | 2.7V to 5.5V-compatible with single Li-ion, dual alkaline, or USB-powered systems. |
Pinout & Package
SOT25 (5-pin, lead-free, RoHS-compliant, "Green" halogen/antimony-free) surface-mount package with 2.9mm × 1.6mm footprint and 1.1mm height.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input Power Supply | Accepts 2.7–5.5V; requires ≥0.1μF input decoupling close to pin. |
| GND | Ground Reference | Common return path for all internal circuits and output capacitor. |
| EN | Enable Control | Active-low logic input; pulls <0.1μA; floating defaults to ON; drives <2μA standby current when low. |
| BYP | Bypass Node | Connects to 10nF capacitor to GND to reduce noise and improve PSRR above 10kHz. |
| VOUT | Regulated Output | Delivers 2.8V ±2% with ≥1.0μF low-ESR ceramic output capacitor. |
Key Features
| Feature | Design Value |
|---|---|
| Low Dropout Operation | 0.45V max at full 300mA load enables use with weak or depleting batteries. |
| Ultra-Low Quiescent Current | 45μA typical allows >1-year runtime on coin-cell batteries in sleep-mode IoT nodes. |
| Integrated Protection | Thermal shutdown (+130°C) and current limiting (300–450mA) eliminate need for external fault management. |
| Bypass-Enhanced PSRR | 75dB @ 1kHz with 10nF BYP cap suppresses switching noise from upstream DC-DC converters. |
| Stability with Low-ESR Caps | Works reliably with 1.0μF+ ceramic output caps-no ESR tuning required for stability. |
Applications
| Wearable Health Monitor | USB-Powered Peripheral |
|---|---|
Use Scenario: Continuous ECG signal acquisition in wrist-worn sensor using coin-cell battery. IC Role / Device Role / Timing Role: Provides clean, low-noise 2.8V supply to analog front-end and ADC, enabled only during sampling bursts. Use Value: 45μA IQ extends battery life beyond 12 months; 75dB PSRR prevents switching noise from MCU's USB PHY from corrupting microvolt-level biopotential signals. | Use Scenario: Compact USB-to-serial adapter powered directly from USB 5V bus. IC Role / Device Role / Timing Role: Regulates 5V USB input to stable 2.8V for 3.3V-tolerant UART transceiver IC. Use Value: 0.45V dropout ensures reliable 2.8V output even as USB port voltage sags to 4.75V; SOT25 footprint minimizes PCB area in space-constrained dongle design. |
| Smart Home Sensor Node | Industrial Handheld Scanner |
Use Scenario: Battery-operated Zigbee temperature/humidity node deployed in remote locations. IC Role / Device Role / Timing Role: Powers RF SoC and digital sensor interface during periodic wake-up and transmission cycles. Use Value: EN pin enables full system shutdown between readings, reducing average current to <1μA; ±2% accuracy maintains consistent RF output power calibration across temperature. | Use Scenario: Rugged handheld barcode scanner with Li-ion battery and OLED display. IC Role / Device Role / Timing Role: Supplies 2.8V to display driver IC while surviving repeated 5.5V input transients from hot-plug battery swaps. Use Value: Absolute max VIN = +6V and thermal shutdown protect against overvoltage events; 300mA rating supports peak display backlight current without droop. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7343-28SAG-7 | Successor part: 2.8V, 300mA, 25μA IQ, improved PSRR (80dB @ 1kHz), same SOT25 package. | Lower IQ and higher PSRR suit ultra-low-power or high-EMI environments where AP139-28WG-7 may require additional filtering. | Select for new designs requiring longer battery life or stricter noise immunity; pin-compatible drop-in replacement. |
| MCP1700-2802E/TO | 2.8V, 250mA, 1.6μA IQ, TO-92 package; no BYP pin, lower current, different thermal profile. | Through-hole mounting and nano-power IQ benefit prototyping or low-volume industrial controls-but lacks current capability for portable loads. | Choose only for legacy through-hole assembly or sub-250mA applications where ultra-low IQ outweighs package size and output current needs. |
Compared with AP7343-28SAG-7, AP139-28WG-7 offers proven field reliability but higher IQ and lower PSRR; versus MCP1700-2802E/TO, it delivers 300mA in SOT25 but requires BYP capacitor and consumes more quiescent current-making it better suited for compact, moderate-power battery devices where board space is constrained.
Availability
AP139-28WG-7 is available at Aetrix Electronics and suitable for wearable health monitors, smart home sensor nodes, USB-powered peripherals, and industrial handheld scanners requiring stable component supply with known lifecycle status.
Supply support for AP139-28WG-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 high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.
The AP139 series belongs to Diodes' low-noise, low-IQ LDO portfolio, engineered specifically for battery-powered portable electronics where extended runtime, small footprint, and robust protection are mandatory.
FAQ
What is the minimum input voltage required for AP139-28WG-7 to maintain regulation at 300mA?
The minimum input voltage is calculated as VOUT + VDROPOUT = 2.8V + 0.45V = 3.25V. Below this, the device enters dropout and output voltage drops linearly with VIN. This value assumes worst-case 0.45V dropout at 300mA and 25°C ambient; derating is recommended for high-temperature operation.
Is the BYP pin mandatory, and what happens if it's left unconnected?
Yes-the 10nF BYP-to-GND capacitor is mandatory for specified low-noise and PSRR performance. Without it, PSRR degrades significantly (e.g., drops from 75dB to ~50dB at 1kHz), and output noise increases by >10×. Leaving BYP open violates the recommended operating conditions and risks unstable regulation under dynamic load.
Can AP139-28WG-7 be used in automotive applications?
No-AP139-28WG-7 is not AEC-Q100 qualified and is marked NRND (Not Recommended for New Designs). Diodes offers automotive-grade alternatives like the AP7361 series, which undergo PPAP, operate across –40°C to +125°C, and are manufactured in IATF 16949-certified facilities.
How does the EN pin behave during power-up, and what pull-up is required?
The EN pin floats internally high and requires no external pull-up to enable operation. When pulled below 0.8V (VEL), the device shuts down with <2μA standby current. For controlled sequencing, a simple resistor divider or GPIO can drive EN; leakage is <0.1μA, so even high-value resistors (e.g., 10MΩ) ensure reliable logic levels.
AP139-28WG-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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
AP139-28WG-7 FAQ
1.How can I place an order for AP139-28WG-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP139-28WG-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 AP139-28WG-7 reliable?
The price and inventory of AP139-28WG-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP139-28WG-7 is usually 5 days.
3.What payment methods are accepted for AP139-28WG-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP139-28WG-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP139-28WG-7?
AP139-28WG-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP139-28WG-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 AP139-28WG-7?
For technical support, including AP139-28WG-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP139-28WG-7 requirements.
6.How does Aetrix verify that AP139-28WG-7 is sourced from the original manufacturer or authorized distributors?
All AP139-28WG-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 AP139-28WG-7 meets industry standards.
7.What is the process for return or replacement of AP139-28WG-7?
All AP139-28WG-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP139-28WG-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 AP139-28WG-7 part is unused and in its original packaging.
Return procedure for AP139-28WG-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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