Diodes Incorporated AP7341-18FS4-7

Overview

AP7341-18FS4-7 from Diodes Incorporated is a 300mA, 1.8V fixed-output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz), designed for RF supply rails in compact portable devices. It operates from 1.7V to 5.25V input, draws only 35µA quiescent current, and features enable control and thermal protection.

For engineers reviewing the AP7341-18FS4-7 datasheet, AP7341-18FS4-7 pinout, AP7341-18FS4-7 application, or AP7341-18FS4-7 equivalent, key selection criteria include dropout voltage at 300mA (≤270mV at V_OUT = 1.8V), EN logic thresholds (0.5V_IL/1.3V_IH), thermal pad layout requirements, and compatibility with 1µF ceramic output capacitors.

Technical Context

The AP7341-18FS4-7 implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, and current-limit circuitry. Its enable input directly controls NMOS pass transistor gate drive, enabling fast turn-on/turn-off transitions and ultra-low standby current (≤1.0µA).

Designed for high-PSRR noise-sensitive rails, it achieves 75dB ripple rejection at 1kHz and maintains stability with minimal 1.0µF ceramic output capacitance. The X2-DFN1010-4 package includes an exposed thermal pad optimized for PCB copper area connection to GND for thermal dissipation.

Key Specifications

Pinout & Package

AP7341-18FS4-7 uses the X2-DFN1010-4 (1.0mm × 1.0mm, 0.4mm pitch) package with wettable flank leads and an exposed thermal pad (Pin 5, not electrically connected). PCB layout requires direct connection of the thermal pad to a GND copper pour for thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with MCP1700-1802E/TO and XC6206P182MR-G, the AP7341-18FS4-7 uniquely combines enable control, ultra-low noise, and thermally optimized DFN packaging - making it optimal for high-density, battery-powered RF systems demanding dynamic power management and strict noise budgets.

Availability

AP7341-18FS4-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, mobile camera sensor core supply, wireless communication SoC I/O rails, and portable media player audio codec supply requiring stable component supply across production lifecycles.

Supply support for AP7341-18FS4-7 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 consumer, industrial, and communications markets.

The AP7341 series targets portable electronics requiring high-PSRR, low-noise, and ultra-low-I_Q LDOs - specifically engineered for RF, imaging, and high-speed interface power domains in space-constrained devices.

FAQ

What is the minimum input voltage required for AP7341-18FS4-7 to maintain regulation at 300mA load?

The AP7341-18FS4-7 requires a minimum input voltage of 2.07V to sustain 1.8V output at 300mA, based on its maximum dropout voltage of 270mV at that load. Below this threshold, output voltage drops linearly with input; operation below 1.7V input is prohibited per absolute maximum ratings.

Can the thermal pad of the X2-DFN1010-4 package be left unconnected?

No - the exposed thermal pad must be soldered to a PCB copper area connected to GND for adequate thermal dissipation. Leaving it unconnected reduces power handling capability and risks thermal shutdown under 300mA continuous load. Diodes Incorporated recommends a minimum 2mm² GND copper pour beneath the pad.

Does AP7341-18FS4-7 include output auto-discharge functionality?

No - the AP7341-18FS4-7 is the non-discharge version (no 'D' suffix). When disabled via EN pin, the output remains floating and retains charge until external leakage discharges it. For active discharge, select AP7341D-18FS4-7, which integrates a 30Ω N-channel FET between VOUT and GND.

What is the recommended input capacitor value and placement for AP7341-18FS4-7?

A minimum 0.47µF X5R/X7R ceramic capacitor is required between VIN and GND, placed within 2mm of the device pins using wide, low-inductance traces. For systems with large transient loads, add a 4.7µF–10µF bulk capacitor nearby to prevent input droop during step-load events.