Diodes Incorporated AP131-30WL-7

Overview

AP131-30WL-7 from Diodes Incorporated is a 300mA fixed-output (3.0V) low-dropout linear regulator in SOT25 package, featuring 400mV dropout at full load, 50µA quiescent current, and active-low enable control. It integrates current limit, thermal shutdown, and bandgap reference for battery-powered wireless modules and PC peripherals requiring stable low-noise voltage regulation.

For engineers reviewing the AP131-30WL-7 datasheet, AP131-30WL-7 pinout, AP131-30WL-7 application, or AP131-30WL-7 equivalent, key selection criteria include dropout voltage under 300mA load, ±2% output accuracy across temperature, EN pin logic thresholds (VENON ≥1.5V), BP pin noise-filtering capability, and SOT25 thermal resistance (θJA = 163°C/W).

Technical Context

The AP131-30WL-7 uses a PMOS pass element with internal 1.5Ω R_ON, enabling low dropout and zero base current draw. Its error amplifier compares feedback from the fixed 3.0V bandgap reference against output voltage, delivering fast transient response and ≤35mV load regulation over 1–300mA.

Shutdown is implemented via an active-low EN pin with <0.1µA leakage and defined V_ENOFF ≤0.8V. The BP pin connects to an external 0.1µF capacitor to reduce output noise, while built-in short-circuit foldback and thermal shutdown protect under fault conditions without external components.

Key Specifications

Pinout & Package

SOT25 (5-pin, lead-free, halogen-free "Green" package; 3.0mm × 1.6mm footprint, 1.1mm height, 0.95mm pitch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO applications.

Compared with AP7343-30W5-7 and MCP1700-3002E/TO, the AP131-30WL-7 offers optimal balance of low dropout, moderate IQ, integrated BP noise filtering, and SOT25 compatibility-making it ideal for space-constrained, battery-operated 3.0V systems where EN polarity and thermal performance are critical.

Availability

AP131-30WL-7 is available at Aetrix Electronics and suitable for wireless sensor nodes, USB peripheral controllers, and industrial data loggers requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for AP131-30WL-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 targets cost-sensitive, space-constrained battery-powered applications needing reliable fixed-output LDOs with integrated protection and low-noise operation-designed specifically for PC peripherals, optical drives, and wireless modules.

FAQ

What is the minimum input voltage required for AP131-30WL-7 to maintain regulated 3.0V output at 300mA?

The minimum input is 3.4V, calculated from the typical 400mV dropout voltage plus the 3.0V output. At 300mA load and 25°C, regulation holds down to VIN = VOUT + VDROP = 3.0V + 0.4V = 3.4V. Below this, output drops linearly with input.

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

Yes, the BP pin may be left floating, but doing so degrades PSRR by up to 20dB below 10kHz and increases output noise by 2–3×. For applications requiring clean analog supplies (e.g., ADC references), a 0.1µF X7R capacitor to ground is mandatory per the datasheet.

Does AP131-30WL-7 support reverse polarity protection, and what happens if IN and GND are swapped?

No, the device has no reverse-polarity protection. Swapping IN and GND forward-biases internal ESD diodes and can cause immediate latch-up or permanent damage. A series Schottky diode on the input is required for reverse-voltage tolerance beyond absolute maximum rating of –0.3V on IN.

How does thermal shutdown behave during continuous overload, and is automatic recovery supported?

Thermal shutdown activates at TJ ≈ 150°C, disabling the pass transistor until junction temperature falls by ~20°C (hysteresis). Recovery is fully automatic and does not require cycling EN. Under sustained 300mA load in still air on standard FR-4, shutdown typically occurs after ~60 seconds without heatsinking.