Diodes Incorporated AP7343-30FS4-7B

Overview

AP7343-30FS4-7B from Diodes Incorporated is a 300mA, 3.0V fixed-output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Fabricated on a CMOS process, it features enable control, thermal shutdown, and short-circuit protection, and is optimized for RF supply rails in compact portable electronics.

For engineers reviewing the AP7343-30FS4-7B datasheet, AP7343-30FS4-7B pinout, AP7343-30FS4-7B application, or AP7343-30FS4-7B equivalent, key selection criteria include its 0.22–0.29V dropout at 300mA (V_OUT = 3.0V), 35µA quiescent current, X2-DFN1010-4 (Type B) package footprint, and EN-controlled power sequencing capability.

Technical Context

The AP7343-30FS4-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor in a CMOS-based architecture. Its internal resistor network fixes V_OUT at 3.0V, eliminating external feedback components.

It delivers fast load transient response (≤100µs recovery with 1µF C_OUT) and line transient suppression via high PSRR (≥75dB @ 1kHz), while thermal shutdown activates at +150°C with +20°C hysteresis to ensure robust operation under overload or ambient stress.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed thermal pad (EP) - connect EP to GND plane for optimal thermal performance (R_θJA = 237°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-3002E/MB and XC6210B302MR-G, the AP7343-30FS4-7B uniquely combines 300mA drive, ±1% accuracy, 75dB PSRR, and X2-DFN1010-4 packaging-making it optimal for next-gen compact RF and imaging subsystems where noise, size, and sequencing are co-constrained.

Availability

AP7343-30FS4-7B is available at Aetrix Electronics and suitable for smartphone RF supplies, camera module biasing, and portable media player audio codecs requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP7343-30FS4-7B 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 semiconductor company specializing in discrete, analog, and mixed-signal devices for power management, signal integrity, and connectivity applications.

The AP7343 series targets portable and battery-powered systems requiring high PSRR, low noise, and minimal footprint-designed specifically for RF, imaging, and ultra-low-power subsystems in consumer and industrial edge devices.

FAQ

What is the minimum input voltage required for stable 3.0V output at 300mA?

The AP7343-30FS4-7B requires VIN ≥ 3.22V to maintain regulated 3.0V output at 300mA, based on its maximum dropout voltage of 0.29V (V_OUT = 3.0V, T_A = +25°C, X2-DFN1010-4). Below this, output voltage drops linearly with input; operation below 1.7V VIN is prohibited per absolute maximum ratings.

Can the EN pin be left floating during normal operation?

No. The EN pin must never be left floating: it has no internal pull-up/down and undefined logic states may cause erratic turn-on/turn-off behavior or increased leakage. If unused, tie EN directly to VIN to ensure permanent enable; if controlled, drive with a clean digital signal meeting V_EN(H) ≥ 1.3V and V_EN(L) ≤ 0.5V thresholds.

Is the exposed pad (EP) electrically connected to GND internally?

No. The EP is thermally conductive but electrically isolated. It must be soldered to a PCB copper pour tied to GND for thermal dissipation (R_θJB = 85.7°C/W), but it must not serve as the sole GND connection-PIN2 (GND) remains the mandatory electrical ground reference for the IC's internal circuitry.

Does AP7343-30FS4-7B include output discharge functionality?

No. The "7B" suffix indicates the standard AP7343 variant without auto-discharge. When disabled via EN, the output remains floating (no internal discharge path). For active output discharge, select AP7343D-30FS4-7B, which adds an internal 30Ω NMOS switch between VOUT and GND during shutdown.