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Diodes Incorporated AP7331-18WG-7
- Part No.:
- AP7331-18WG-7
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP7331-18WG-7.pdf
- Description:
- IC REG LINEAR 1.8V 300MA SOT25
- Quantity:
- Payment:
- Shipping:
Inventory:21,620
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Product details
Overview
AP7331-18WG-7 from Diodes Incorporated is a fixed-output 1.8V, 300mA low-dropout linear regulator with enable control, 65μA quiescent current, 300mV dropout at full load, and stable operation with 1μF ceramic output capacitor. It serves as a primary power supply for core logic rails in portable computing and wireless infrastructure where battery life and transient response are critical.
For engineers reviewing the AP7331-18WG-7 datasheet, AP7331-18WG-7 pinout, AP7331-18WG-7 application, or AP7331-18WG-7 equivalent, key selection criteria include low-IQ under light load, fast 80μs startup, ±2% output accuracy over –40°C to +85°C, and compatibility with compact SOT25 packaging for space-constrained PCB layouts.
Technical Context
The AP7331-18WG-7 integrates a PMOS pass transistor, precision 0.4V bandgap reference, error amplifier, thermal shutdown (140°C trip), and current-limit circuitry (600mA typical). Its architecture enables ultra-low quiescent current independent of load due to optimized biasing of internal analog blocks.
It delivers fast transient response via high-gain error amplifier and low-output-impedance driver stage, achieving <±20mV undershoot/overshoot during 300mA load steps. PSRR reaches 65dB at 100Hz, supporting noise-sensitive analog and RF subsystems powered from noisy DC-DC sources.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8V ±2% over –40°C to +85°C - ensures stable core voltage for 1.8V I/O and low-power microcontrollers. |
| Max Output Current | 300mA continuous - sufficient for single-core ARM Cortex-M processors or Wi-Fi baseband ICs. |
| Quiescent Current | 65μA typical at full load - minimizes standby power loss in always-on battery-powered nodes. |
| Dropout Voltage | 300mV typical at 300mA - enables regulation from 2.1V input (e.g., single Li-ion cell post-boost). |
| PSRR | 65dB at 100Hz - suppresses ripple from switching converters feeding the LDO input. |
| Startup Time | 80μs - supports rapid wake-up from deep-sleep modes in portable devices. |
| Thermal Shutdown | 140°C junction threshold with 15°C hysteresis - prevents permanent damage during sustained overload or poor heatsinking. |
Pinout & Package
AP7331-18WG-7 is packaged in RoHS-compliant, lead-free SOT25 (SC-74A) - a 5-pin, surface-mount package with 1.6mm × 2.9mm footprint and 1.1mm height. Thermal resistance θJA is 190°C/W on standard FR-4 PCB with minimum pad layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - IN | Input voltage supply | Accepts 2V–6V; requires ≥1μF ceramic bypass capacitor placed adjacent to pin for stability and noise rejection. |
| 2 - GND | Power ground reference | Common return path for input/output currents; must connect to low-impedance ground plane to minimize noise coupling. |
| 3 - EN | Enable control input | Active-high logic interface (VIH ≥1.4V); ties to IN for always-on operation or drives from MCU GPIO for dynamic power gating. |
| 4 - NC | No connection | Internally unconnected; must remain floating - no external tie or pull-up/down required. |
| 5 - OUT | Regulated output | Delivers 1.8V ±2%; requires ≥1μF ceramic capacitor at pin for transient stability and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Low-IQ across load range | 65μA typical at 300mA - eliminates need for external disable circuitry in energy-harvesting or coin-cell applications. |
| Stable with 1μF ceramic COUT | Eliminates bulk tantalum capacitors - reduces BOM cost, board area, and failure risk from capacitor aging. |
| Fast line/load transient response | Controlled overshoot/undershoot (<±20mV) during 300mA step loads - avoids logic glitches in high-speed digital ICs. |
| Integrated protection suite | Current limit (600mA), short-circuit clamp (100mA), and thermal shutdown (140°C) - enables robust operation without external fault management. |
| Wide input voltage range | 2V–6V operation - supports direct connection to single-cell Li-ion (2.7–4.2V), USB (5V), or boosted 3.3V rails. |
Applications
| Wireless LAN Modules | XDSL Router Power Rails |
|---|---|
|
Use Scenario: Powering 2.4GHz/5GHz WLAN baseband ICs and RF transceivers in compact residential gateways. IC Role / Device Role / Timing Role: Primary 1.8V supply for PHY/MAC logic and memory interfaces requiring low noise and fast wake-up. Use Value: 65μA IQ extends standby time between beacon intervals; 80μs startup synchronizes with MAC layer sleep-wake cycles. |
Use Scenario: Generating clean 1.8V for DSL line drivers and analog front-end (AFE) circuits in ADSL2+/VDSL2 modems. IC Role / Device Role / Timing Role: Low-noise post-regulator after buck converter, suppressing switching ripple that degrades SNR in upstream/downstream channels. Use Value: 65dB PSRR at 100Hz attenuates 500kHz–1MHz buck ripple by >1,800×, improving upstream bit error rate (BER). |
| Notebook CPU I/O Voltage | Industrial Sensor Node Core Supply |
|
Use Scenario: Supplying 1.8V I/O banks for embedded controllers and touchpad interfaces in fanless ultrabooks. IC Role / Device Role / Timing Role: Local point-of-load regulator decoupling high-speed serial links (e.g., I²C, SPI) from main system rail noise. Use Value: 300mV dropout allows operation down to 2.1V input - compatible with partially discharged 2S Li-ion packs during peak CPU load. |
Use Scenario: Powering ultra-low-power microcontrollers (e.g., ARM Cortex-M0+) and MEMS sensors in battery-operated condition monitoring nodes. IC Role / Device Role / Timing Role: Always-on voltage source enabling sub-10μA sleep current while maintaining RTC and wake-on-interrupt capability. Use Value: 65μA quiescent current contributes <0.5% of total 12-month battery drain - extends 10-year deployment target. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1700T-1802E/TT | 250mA max output, 1.6μA IQ, no enable pin, SOT23-5 package | Lacks EN control and 300mA headroom - unsuitable for burst-mode wireless transceivers | Select when lowest possible standby current is mandatory and enable functionality is unused. |
| Torex XC6206P182MR-G | 300mA output, 12μA IQ, no thermal shutdown, SOT23-5 | Missing thermal protection - requires derating in enclosed industrial enclosures above 60°C ambient | Select for minimal IQ in thermally benign environments where board-level thermal monitoring exists. |
Compared with MCP1700T-1802E/TT and XC6206P182MR-G, AP7331-18WG-7 uniquely balances 300mA drive capability, 65μA IQ, integrated EN control, and full protection set - making it optimal for space-constrained, battery-powered systems demanding both efficiency and reliability.
Availability
AP7331-18WG-7 is available at Aetrix Electronics and suitable for wireless LAN modules, XDSL router power rails, and notebook CPU I/O voltage regulation requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for AP7331-18WG-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 communications markets.
The AP7331 series targets portable and infrastructure power management, designed specifically to replace legacy LDOs in battery-powered equipment where ultra-low quiescent current, fast transient response, and small-footprint packaging are essential.
FAQ
What is the minimum input voltage required for AP7331-18WG-7 to maintain regulation at 300mA?
The AP7331-18WG-7 requires a minimum input voltage of 2.1V to sustain 1.8V output at 300mA, based on its typical 300mV dropout voltage specification. At lower input voltages (e.g., 2.05V), output regulation degrades beyond ±2% tolerance, triggering dropout behavior. Input must remain ≥2V absolute per Absolute Maximum Ratings.
Can AP7331-18WG-7 operate without an output capacitor?
No - AP7331-18WG-7 requires a minimum 1μF ceramic output capacitor connected directly between OUT and GND for stability and transient response. Omitting it causes oscillation, excessive output ripple, and potential thermal runaway under load. The device is not internally compensated for zero-COUT operation.
Is the NC pin on AP7331-18WG-7 electrically isolated or tied internally?
The NC (pin 4) on AP7331-18WG-7 is fully electrically isolated - no internal connection to silicon or bond wires. It must remain unconnected on the PCB; soldering or routing to any net may compromise thermal performance or induce parasitic coupling. Diodes Incorporated confirms this in the Pin Descriptions table of DS31914 Rev. 3-2.
How does thermal shutdown behave during sustained overload?
When junction temperature reaches ~140°C, AP7331-18WG-7 disables the pass transistor and forces OUT to drop to near-zero voltage. After cooling to ~125°C (15°C hysteresis), it automatically resumes regulation. Under continuous overload, this results in thermal cycling - visible as periodic output voltage toggling - which protects the die but requires system-level current limiting to prevent damage.
AP7331-18WG-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):
- 6V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- -
- Current - Output:
- 300mA
- Current - Quiescent (Iq):
- 75 µA
- Current - Supply (Max):
- 85 µA
- PSRR:
- 65dB (100Hz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-25
AP7331-18WG-7 FAQ
1.How can I place an order for AP7331-18WG-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP7331-18WG-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 AP7331-18WG-7 reliable?
The price and inventory of AP7331-18WG-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7331-18WG-7 is usually 5 days.
3.What payment methods are accepted for AP7331-18WG-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7331-18WG-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP7331-18WG-7?
AP7331-18WG-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP7331-18WG-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 AP7331-18WG-7?
For technical support, including AP7331-18WG-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7331-18WG-7 requirements.
6.How does Aetrix verify that AP7331-18WG-7 is sourced from the original manufacturer or authorized distributors?
All AP7331-18WG-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 AP7331-18WG-7 meets industry standards.
7.What is the process for return or replacement of AP7331-18WG-7?
All AP7331-18WG-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP7331-18WG-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 AP7331-18WG-7 part is unused and in its original packaging.
Return procedure for AP7331-18WG-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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