Diodes Incorporated AP7341-185FS4-7

Overview

AP7341-185FS4-7 from Diodes Incorporated is a 300mA, 1.85V fixed-output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, thermal shutdown, short-circuit protection, and operates from 1.7V to 5.25V input - optimized for RF supply rails in compact portable devices.

For engineers reviewing the AP7341-185FS4-7 datasheet, AP7341-185FS4-7 pinout, AP7341-185FS4-7 application, or AP7341-185FS4-7 equivalent, key selection criteria include dropout voltage at 300mA (0.21–0.27V for 1.85V output), EN logic thresholds (0.5V max low, 1.3V min high), thermal pad layout guidance, and compatibility with 1µF ceramic output capacitors.

Technical Context

The AP7341-185FS4-7 uses a CMOS-based LDO architecture with integrated voltage reference, error amplifier, and current-limit circuitry. Its enable input controls NMOS pass transistor conduction, supporting fast turn-on/turn-off with defined VIH/VIL thresholds and sub-1µA standby current.

Designed for noise-sensitive analog and RF subsystems, it delivers stable 1.85V output under load transients up to 300mA while maintaining 75dB ripple rejection at 1kHz and ultra-low 60µV_rms integrated noise - enabled by low-R_DS(ON) pass element and internal compensation.

Key Specifications

Pinout & Package

The AP7341-185FS4-7 is housed in a 1.0mm × 1.0mm X2-DFN1010-4 package with exposed thermal pad (pin 5, non-electrical). PCB layout requires direct connection of the thermal pad to GND plane for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and XC6206P182MR-G, the AP7341-185FS4-7 uniquely combines 300mA capability, 1.85V precision output, enable control, thermal pad, and industry-leading PSRR in a 1.0mm² DFN - making it optimal for space-constrained, thermally demanding RF and imaging subsystems.

Availability

AP7341-185FS4-7 is available at Aetrix Electronics and suitable for RF transceiver power, camera sensor bias, portable media decoder, and wireless adapter core logic requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7341-185FS4-7 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-performance power management, signal integrity, and protection solutions for consumer, industrial, and communications markets.

The AP7341 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive RF, imaging, and portable electronics applications where power integrity directly impacts system-level performance.

FAQ

What is the minimum input voltage required for AP7341-185FS4-7 to maintain regulation at full 300mA load?

The minimum input voltage is calculated as V_OUT + V_DROP = 1.85V + 0.27V = 2.12V, based on maximum dropout voltage specified at 300mA and T_A = +25°C. At −40°C or +85°C, dropout increases slightly; design margin should include worst-case 0.30V for robust operation across temperature.

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

No - the thermal pad must be soldered to a PCB copper area connected to GND for effective heat dissipation. Leaving it unconnected degrades thermal resistance by >50%, risking thermal shutdown above ~150mW power dissipation (e.g., at 300mA with 0.3V dropout). The datasheet explicitly recommends large GND-connected copper coverage.

Does AP7341-185FS4-7 include output discharge functionality?

No - the "D" suffix (e.g., AP7341D-185FS4-7) denotes the discharge version with internal NMOS between VOUT and GND. The standard AP7341-185FS4-7 lacks this feature; VOUT remains floating after disable unless external discharge circuitry is added.

Is a minimum 1µF output capacitor mandatory for stability?

Yes - the AP7341-185FS4-7 is optimized for ceramic capacitors ≥1µF with ESR <100mΩ. Using smaller values risks instability and oscillation, especially under load transients. The datasheet confirms stability with 1µF COUT and specifies ESR vs. I_OUT curves to guide capacitor selection.