Diodes Incorporated AP7343-295FS4-7B

Overview

AP7343-295FS4-7B from Diodes Incorporated is a 300mA, 2.95V 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 electronics using the X2-DFN1010-4 (Type B) package.

For engineers reviewing the AP7343-295FS4-7B datasheet, AP7343-295FS4-7B pinout, AP7343-295FS4-7B application, or AP7343-295FS4-7B equivalent, key selection criteria include its 35µA quiescent current, 0.22–0.29V dropout at 300mA, enable-controlled shutdown, and thermal shutdown at +150°C - all critical for battery-powered RF subsystems requiring stable low-noise bias.

Technical Context

The AP7343-295FS4-7B implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, current limit, and thermal shutdown circuitry. Its EN pin provides precise on/off control with 0–0.5V logic-low and 1.3–5.25V logic-high thresholds, enabling system-level power sequencing.

It delivers regulated 2.95V output across 1.7–5.25V input range with guaranteed 300mA load capability and maintains stability with ≥1µF ceramic output capacitance. The X2-DFN1010-4 (Type B) package features an exposed pad optimized for thermal dissipation via PCB copper area connected to GND.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, 4 active terminals + exposed thermal pad (EP). EP must be connected to GND via large copper area for optimal thermal performance (R_θJB = 85.7°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-3002E/MB and XC6210B295MR-G, the AP7343-295FS4-7B uniquely combines 2.95V precision, 75dB PSRR, and 1.0mm² footprint with thermal pad - making it optimal for space-constrained, noise-critical RF power stages where thermal headroom and spectral purity are non-negotiable.

Availability

AP7343-295FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier bias, Wi-Fi transceiver core supply, camera ISP core rails, and portable GPS LNA supply requiring stable component supply across high-mix, low-volume production runs.

Supply support for AP7343-295FS4-7B 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 automotive markets.

The AP7343 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive RF and imaging subsystems in portable wireless devices where board space, battery life, and signal fidelity are tightly coupled constraints.

FAQ

What is the minimum input voltage required for stable 2.95V output at 300mA load?

The AP7343-295FS4-7B requires VIN ≥ 3.17V (2.95V + 0.22V dropout) for full 300mA output at room temperature. At -40°C, dropout rises to 0.29V, so VIN ≥ 3.24V is recommended for guaranteed operation across the full temperature range.

Can the EN pin be left unconnected if always-on operation is needed?

No - the EN pin must never be left floating. For always-on operation, tie EN directly to VIN. This ensures reliable activation above the 1.3V logic-high threshold and avoids erratic startup or shutdown due to noise coupling.

Is an output capacitor mandatory, and what type is recommended?

Yes - a minimum 1µF ceramic capacitor is mandatory between VOUT and GND for stability and transient response. X5R or X7R dielectrics with ≤10mΩ ESR are recommended; place it within 2mm of VOUT/GND pins to minimize loop inductance.

Does AP7343-295FS4-7B include reverse-current protection or output discharge?

No - the AP7343-295FS4-7B is the non-discharge variant (no internal pull-down FET). When disabled, VOUT remains floating and discharges only through external load or parasitic paths. For controlled discharge, select AP7343D-295FS4-7B instead.