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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Diodes Incorporated AP131-28WG-7

Name: AP131-28WG-7
Brand: Diodes Incorporated
SKU: AP131-28WG-7
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP131-28WG-7

Manufacturer:: Diodes Incorporated

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: SC-74A, SOT-753

Datasheet:: AP131-28WG-7.pdf

Description:: IC REG LINEAR 2.8V 300MA SOT25

Quantity:: RFQ Add To RFQ list

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Inventory:4,127

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Product details

Overview

AP131-28WG-7 from Diodes Incorporated is a 300mA fixed-output (2.8V) low-dropout linear regulator in SOT25 package, featuring 400mV dropout at full load, 50µA quiescent current, and active-low enable control. It integrates current limiting, thermal shutdown, and bandgap reference with BP pin for noise reduction-designed for battery-powered wireless modules and PC peripherals requiring stable low-noise voltage regulation.

For engineers reviewing the AP131-28WG-7 datasheet, AP131-28WG-7 pinout, AP131-28WG-7 application, or AP131-28WG-7 equivalent, key selection criteria include dropout performance at 300mA, ±2% output accuracy over temperature, EN pin logic thresholds (VENON ≥1.5V), PSRR of 60dB at 100Hz, and thermal resistance (θJA = 163°C/W) under standard SOT25 PCB layout.

Technical Context

The AP131-28WG-7 employs a PMOS pass element with internal 1.5Ω R_ON, eliminating base drive current and enabling ultra-low quiescent current. Its error amplifier compares feedback from the bandgap reference to regulate V_OUT with <30mV load regulation across 1–300mA.

Shutdown is controlled via an active-low EN pin with sub-0.1µA leakage and 8µs delay (with 0.1µF BP capacitor). The BP pin connects to an external capacitor to filter bandgap noise, directly improving output voltage stability and PSRR above 10kHz.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 2.8V ±2% - ensures precise rail generation for 2.8V I/O or core logic without external resistors
Dropout Voltage	400mV typ. at 300mA - enables operation down to 3.2V input while maintaining regulation
Quiescent Current	50µA typ. - minimizes standby power loss in battery-critical applications like Bluetooth modules
PSRR	60dB at 100Hz - suppresses switching noise from upstream DC/DC converters feeding the LDO
Thermal Shutdown	Active at T_J ≥ +125°C - protects device during sustained overload or poor heatsinking
Enable Threshold	V_ENON ≥ 1.5V, V_ENOFF ≤ 0.8V - compatible with 1.8V/3.3V GPIO without level-shifting
Current Limit	350–450mA - provides fold-back short-circuit protection while allowing brief inrush currents

Pinout & Package

SOT25 (5-pin) surface-mount package with exposed pad not electrically connected; JEDEC MO-203AA compliant, footprint optimized for thermal dissipation on 2oz copper FR-4 board.

Pin/Terminal	Circuit Role	Design Meaning
1 (IN)	Input voltage supply	Accepts 2.7–5.5V; requires 1µF ceramic input capacitor for stability
2 (EN)	Enable control input	Active-low logic; pulls output to GND when <0.8V; draws <0.1µA
3 (BP)	Bandgap bypass node	Connects 0.1µF capacitor to reduce reference noise and improve PSRR
4 (OUT)	Regulated output	Delivers up to 300mA at 2.8V ±2%; requires 10µF ceramic output capacitor
5 (GND)	Power ground reference	Common return path for IN, OUT, EN, and BP; must be low-impedance

Key Features

Feature	Design Value
Low-quiescent-current PMOS architecture	50µA IQ across 0–300mA load eliminates need for external biasing and extends battery life
Integrated bandgap reference with BP pin	0.1µF BP capacitor reduces output noise by >20dB and improves transient response fidelity
Fast enable/disable timing	8µs EN delay enables synchronized power sequencing in multi-rail systems
Robust fault protection	Thermal shutdown + current limit + short-circuit fold-back prevent latch-up or destruction under fault
Green RoHS-compliant packaging	SOT25 with halogen/antimony-free molding compound (<900ppm Br+Cl, <1000ppm Sb)

Applications

Battery-Powered Wireless Sensor Node

USB Peripheral Power Management

Use Scenario: Compact BLE sensor node powered by single Li-ion cell (3.0–4.2V) with intermittent RF transmission.

IC Role / Device Role / Timing Role: Primary 2.8V LDO supplying RF transceiver and microcontroller I/O rails.

Use Value: 400mV dropout allows >3.2V operation through battery discharge curve; 50µA IQ extends shelf life beyond 2 years.

Use Scenario: USB 2.0 hub IC requiring clean 2.8V auxiliary supply derived from 5V bus.

IC Role / Device Role / Timing Role: Post-regulator filtering switch-mode ripple before sensitive analog PHY circuitry.

Use Value: 60dB PSRR at 100Hz attenuates 5V DC/DC switching noise; BP capacitor further suppresses high-frequency artifacts.

Optical Drive Logic Supply

Industrial Control I/O Module

Use Scenario: CD/DVD-ROM controller board needing isolated 2.8V for servo motor driver logic and EEPROM interface.

IC Role / Device Role / Timing Role: Dedicated low-noise supply decoupled from noisy motor drivers and digital buses.

Use Value: ±2% output accuracy ensures reliable SPI communication; thermal shutdown prevents damage during motor stall events.

Use Scenario: DIN-rail mounted PLC I/O module with mixed-signal circuitry operating in -40°C to +85°C ambient.

IC Role / Device Role / Timing Role: Local 2.8V rail for ADC reference buffer and isolated CAN transceiver logic.

Use Value: Guaranteed 300mA output supports multiple loads; -40°C to +85°C operating range matches industrial temp grade requirements.

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
AP7343-28W5-7	Higher PSRR (70dB @ 100Hz), lower dropout (250mV @ 300mA), but no BP pin	Better noise rejection in RF-sensitive designs; lacks BP-based noise tuning flexibility	Select when PSRR >65dB is mandatory and BP customization is unnecessary
MCP1703T-2802E/MB	Same 2.8V output, 250mA rating, 6µA quiescent current, SOT-23-5 package	Lower max current and smaller package limit thermal margin in continuous 300mA use	Select only for space-constrained, low-power (<150mA) applications where footprint is critical

Compared with AP7343-28W5-7 and MCP1703T-2802E/MB, the AP131-28WG-7 uniquely balances 300mA capability, BP-adjustable noise performance, and robust thermal protection in SOT25-making it optimal for mid-power battery and peripheral applications where design flexibility and fault resilience are prioritized over minimal IQ or ultra-low dropout.

Availability

AP131-28WG-7 is available at Aetrix Electronics and suitable for battery-powered wireless sensors, USB peripherals, optical drive logic, and industrial I/O modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP131-28WG-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 power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AP131 series belongs to Diodes' precision LDO portfolio, engineered for low-noise, low-IQ regulation in portable and space-constrained electronics where reliability and ease of integration are essential.

FAQ

What is the minimum input voltage required for AP131-28WG-7 to maintain regulation at 300mA?

The minimum input voltage is calculated as V_OUT + V_DROP = 2.8V + 0.4V = 3.2V. At 300mA load and 25°C, regulation is maintained down to 3.2V input; below that, output voltage drops linearly with input. Dropout increases slightly at higher junction temperatures, so derating is recommended above 85°C ambient.

Can the BP pin be left unconnected, and what impact does that have?

Yes, the BP pin may be left floating or tied directly to OUT, but doing so forfeits the noise-reduction benefit. Without the 0.1µF capacitor, PSRR degrades by ~15dB above 10kHz and output voltage ripple increases-particularly noticeable in RF or high-resolution ADC applications where reference stability is critical.

Is AP131-28WG-7 compatible with ceramic output capacitors, and what ESR range is supported?

Yes, it is fully compatible with low-ESR ceramic capacitors. The datasheet specifies 10µF X5R/X7R ceramic at the output; ESR values from 5mΩ to 100mΩ are acceptable. Unlike older LDOs, it does not require minimum ESR for stability due to its internal compensation and PMOS architecture.

Does AP131-28WG-7 support reverse-voltage or reverse-current protection?

No, the device lacks integrated reverse-voltage or reverse-current protection. If input can fall below output (e.g., during hot-swap or backup battery scenarios), an external Schottky diode between IN and OUT is required to prevent backfeed and potential damage to upstream circuitry.

AP131-28WG-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):: 0.5V @ 300mA

Current - Output:: 300mA

Current - Quiescent (Iq):: 100 µA

Current - Supply (Max):: -

PSRR:: 60dB (100Hz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-25

AP131-28WG-7 FAQ

1.How can I place an order for AP131-28WG-7 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP131-28WG-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 AP131-28WG-7 reliable?

The price and inventory of AP131-28WG-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP131-28WG-7 is usually 5 days.

3.What payment methods are accepted for AP131-28WG-7?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP131-28WG-7 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP131-28WG-7?

AP131-28WG-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP131-28WG-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 AP131-28WG-7?

For technical support, including AP131-28WG-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP131-28WG-7 requirements.

6.How does Aetrix verify that AP131-28WG-7 is sourced from the original manufacturer or authorized distributors?

All AP131-28WG-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 AP131-28WG-7 meets industry standards.

7.What is the process for return or replacement of AP131-28WG-7?

All AP131-28WG-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP131-28WG-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 AP131-28WG-7 part is unused and in its original packaging.

Return procedure for AP131-28WG-7:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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