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Diodes Incorporated AP139-18WG-7
- Part No.:
- AP139-18WG-7
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP139-18WG-7.pdf
- Description:
- IC REG LINEAR 1.8V 300MA SOT25
- Quantity:
- Payment:
- Shipping:
Inventory:215
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Product details
Overview
AP139-18WG-7 from Diodes Incorporated is a 1.8V, 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 AP139-18WG-7 datasheet, AP139-18WG-7 pinout, AP139-18WG-7 application, or AP139-18WG-7 equivalent, key selection criteria include dropout performance at full load, PSRR above 60dB at 1kHz with 10nF bypass, EN pin threshold (1.7V ON / 0.8V OFF), stability with ≥1.0μF low-ESR output capacitor, and thermal protection activation at +130°C.
Technical Context
The AP139-18WG-7 employs a pMOS pass transistor architecture with internal precision voltage reference and error amplifier feedback loop, enabling tight regulation across input range (2.7V–5.5V) and load (0–300mA). Its low-quiescent-current design maintains 45μA typical IQ while delivering 1.8V ±2% output under varying temperature and line conditions.
Enable functionality provides true shutdown mode (<2μA standby current) via active-low EN pin; bypass pin (BYP) accepts 10nF capacitor to enhance PSRR-achieving 75dB at 1kHz-and suppresses internal reference noise. Thermal shutdown triggers at +130°C with +20°C hysteresis, restoring operation only after junction cools to +110°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.8V ±2% - ensures stable core/bias rail for 1.8V logic and RF ICs |
| Max Output Current | 300mA - supports moderate-power microcontrollers and sensors without derating |
| Dropout Voltage | ≤0.45V @ 300mA - enables operation down to VIN = 2.25V while maintaining regulation |
| Quiescent Current | 45μA typ - extends battery life in always-on wearable and IoT edge nodes |
| PSRR | 75dB @ 1kHz (with 10nF BYP cap) - suppresses switching noise from adjacent DC/DC converters |
| Thermal Shutdown | +130°C activation - prevents permanent damage during sustained overload or poor PCB thermal layout |
| Input Voltage Range | 2.7V to 5.5V - compatible with single Li-ion, Li-poly, or dual-AA/AAA battery stacks |
Pinout & Package
SOT25 (5-pin, lead-free, RoHS-compliant, halogen-free "Green" package; 2.9mm × 1.6mm footprint, 1.1mm height).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power Input | Accepts 2.7–5.5V supply; requires ≥0.1μF ceramic decoupling close to pin |
| GND | Ground Reference | Common return path for all internal circuits and output capacitor; must connect to low-impedance ground plane |
| EN | Enable Control | Active-low digital input; pulls <0.1μA; drives device into <2μA shutdown when held ≤0.8V |
| BYP | Bypass Node | Connects to 10nF capacitor to ground to stabilize internal reference and boost PSRR |
| VOUT | Regulated Output | Delivers 1.8V ±2%; stable with ≥1.0μF low-ESR ceramic capacitor to GND |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise regulation | 10nF BYP capacitor enables 75dB PSRR at 1kHz-critical for noise-sensitive analog/RF stages |
| Ultra-low IQ | 45μA typical quiescent current minimizes standby power loss in battery-backed systems |
| Robust protection | Integrated thermal shutdown (+130°C) and current limit (300–450mA) prevent failure under fault conditions |
| Wide input compatibility | 2.7–5.5V input range supports direct connection to common battery chemistries and intermediate rails |
| Small-footprint packaging | SOT25 footprint (2.9×1.6mm) enables high-density layouts in space-constrained handheld devices |
Applications
| Wearable Health Monitors | Wireless Sensor Nodes |
|---|---|
Use Scenario: Continuous ECG/PPG sensing in compact wrist-worn devices powered by coin-cell or thin-film batteries. IC Role / Device Role / Timing Role: Provides ultra-low-noise 1.8V bias for analog front-end amplifiers and ADC reference, minimizing signal distortion. Use Value: 45μA IQ extends battery life beyond 6 months; 75dB PSRR rejects noise from Bluetooth LE radio bursts. | Use Scenario: Battery-operated environmental sensor clusters transmitting data via LoRaWAN or NB-IoT every 10 minutes. IC Role / Device Role / Timing Role: Supplies regulated 1.8V to MCU, temperature/humidity sensor, and transceiver during active transmission bursts. Use Value: 300mA capability handles peak 200mA transmit current; thermal shutdown prevents overheating in sealed enclosures. |
| USB-C Peripheral Adapters | Industrial Handheld Scanners |
Use Scenario: Compact USB-C to HDMI/SD card adapters drawing power from host port while powering internal logic and interface ICs. IC Role / Device Role / Timing Role: Generates clean 1.8V rail for USB PHY, level shifters, and flash memory I/O buffers. Use Value: 0.45V dropout allows operation even as USB-C VBUS sags to 4.5V; EN pin enables dynamic power gating during idle. | Use Scenario: Ruggedized barcode scanners using dual AA alkaline cells (1.8–3.2V range) and requiring reliable operation across -20°C to +60°C ambient. IC Role / Device Role / Timing Role: Regulates variable battery voltage to stable 1.8V for image sensor, decode engine, and display driver. Use Value: ±2% accuracy ensures consistent sensor gain calibration; -40°C to +85°C operating range covers full industrial spec. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7343-18SAG-7 | Successor part: lower IQ (2.5μA typ), improved PSRR (80dB @ 1kHz), same SOT25 package and 1.8V output | Designed for ultra-long-life energy harvesting and coin-cell applications where sub-5μA standby is critical | Select for new designs requiring extended battery life and higher noise immunity; pin-compatible drop-in replacement |
| MCP1700-1802E/TO | 300mA rated, 1.8V fixed, TO-92 package; IQ = 1.6μA typ but larger footprint and lower PSRR (60dB @ 1kHz) | Used in cost-sensitive industrial controls where manual assembly and thermal mass outweigh size constraints | Choose only if TO-92 through-hole assembly is required; not suitable for high-density SMT layouts |
Compared with AP139-18WG-7, AP7343-18SAG-7 delivers 18× lower quiescent current and 5dB higher PSRR-enabling decade-scale battery life in maintenance-free IoT nodes-while MCP1700-1802E/TO trades miniaturization for legacy assembly compatibility and marginal IQ improvement.
Availability
AP139-18WG-7 is available at Aetrix Electronics and suitable for wearable health monitors, wireless sensor nodes, USB-C peripheral adapters, and industrial handheld scanners requiring stable component supply amid evolving battery-voltage constraints.
Supply support for AP139-18WG-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 belongs to Diodes' low-dropout linear regulator product line, engineered specifically for battery-powered portable electronics demanding ultra-low IQ, high accuracy, and robust fault protection in minimal footprints.
FAQ
What is the minimum input voltage required for AP139-18WG-7 to maintain regulation at 300mA load?
The minimum input voltage is calculated as VOUT + VDROPOUT = 1.8V + 0.45V = 2.25V. However, the recommended operating minimum is 2.7V per datasheet specifications to ensure guaranteed performance across temperature, process variation, and line/load regulation. Below 2.7V, dropout margin shrinks and output accuracy may degrade beyond ±2%.
Can AP139-18WG-7 operate without the 10nF bypass capacitor on the BYP pin?
Yes, it will regulate without the 10nF BYP capacitor, but PSRR degrades significantly-dropping from 75dB to ~50dB at 1kHz. The capacitor is mandatory for noise-sensitive applications like audio codecs or RF receivers. Omitting it increases output voltage noise and reduces immunity to input ripple, especially above 10kHz.
Is AP139-18WG-7 qualified for automotive applications?
No. AP139-18WG-7 is not AEC-Q100 qualified and is marked NRND (Not Recommended for New Designs). Diodes offers automotive-grade alternatives such as the AP7361Q 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 is internally weakly pulled up, allowing normal startup without external components. If used actively, a resistor ≤100kΩ to VIN is recommended to ensure fast, deterministic turn-on. Pull-down resistors >10MΩ suffice for shutdown control; leakage current is <0.1μA, so high-impedance GPIOs can drive EN directly without loading.
AP139-18WG-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):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- -
- 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
AP139-18WG-7 FAQ
1.How can I place an order for AP139-18WG-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP139-18WG-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 AP139-18WG-7 reliable?
The price and inventory of AP139-18WG-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP139-18WG-7 is usually 5 days.
3.What payment methods are accepted for AP139-18WG-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP139-18WG-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP139-18WG-7?
AP139-18WG-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP139-18WG-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 AP139-18WG-7?
For technical support, including AP139-18WG-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP139-18WG-7 requirements.
6.How does Aetrix verify that AP139-18WG-7 is sourced from the original manufacturer or authorized distributors?
All AP139-18WG-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 AP139-18WG-7 meets industry standards.
7.What is the process for return or replacement of AP139-18WG-7?
All AP139-18WG-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP139-18WG-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 AP139-18WG-7 part is unused and in its original packaging.
Return procedure for AP139-18WG-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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