Diodes Incorporated AP7343D-34W5-7

Overview

AP7343D-34W5-7 from Diodes Incorporated is a 300mA low-dropout linear regulator with fixed 3.4V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µVrms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, thermal shutdown, short-circuit protection, and is optimized for RF supply rails in portable wireless devices.

For engineers reviewing the AP7343D-34W5-7 datasheet, AP7343D-34W5-7 pinout, AP7343D-34W5-7 application, or AP7343D-34W5-7 equivalent, key selection criteria include dropout voltage at 300mA (≤290mV for SOT25), EN logic thresholds (0.5V low / 1.3V high), discharge functionality (enabled in "D" variant), and thermal resistance (179°C/W in SOT25).

Technical Context

The AP7343D-34W5-7 implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, current limit circuit, and active discharge path activated during shutdown. Its EN pin controls both regulation enablement and output discharge-critical for sequencing-sensitive systems.

Designed for low-noise, high-PSRR operation, it maintains stable regulation across 1.7V–5.25V input range while delivering 3.4V at up to 300mA. The SOT25 package provides 179°C/W junction-to-ambient thermal resistance, enabling reliable operation in compact handheld layouts without external heatsinking.

Key Specifications

Pinout & Package

AP7343D-34W5-7 is packaged in SOT25 (5-pin, 2.9mm × 1.6mm × 1.1mm), featuring an exposed pad for enhanced thermal dissipation. Pin 1 = VIN, Pin 2 = GND, Pin 3 = EN, Pin 4 = VOUT, Pin 5 = NC (no connection). The exposed pad must be connected to PCB ground plane for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-3302E/MB and XC6210B342MR-G, AP7343D-34W5-7 uniquely combines 3.4V precision, integrated discharge, and industry-leading 75dB PSRR-making it the only option among the three qualified for RF PA bias where fast turn-off and ripple rejection are co-required.

Availability

AP7343D-34W5-7 is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera ISP supplies, portable wireless adapter baseband regulation, and portable media player audio codec rails requiring stable component supply, consistent parametric performance, and automotive-grade reliability validation.

Supply support for AP7343D-34W5-7 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 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 battery-powered portable electronics where efficiency, size, and signal integrity are co-constrained.

FAQ

What is the purpose of the NC pin (Pin 5) on AP7343D-34W5-7?

Pin 5 is a no-connect terminal with no internal bond wire or circuit connection. It must remain electrically floating or be tied to GND solely for mechanical stability and thermal conduction-never used as a functional ground node. This design prevents unintended current paths that could compromise ESD robustness or thermal measurement accuracy.

Does AP7343D-34W5-7 require an external discharge resistor?

No. The "D" suffix indicates integrated discharge functionality: an internal NMOS FET actively pulls VOUT to GND when EN is low. This eliminates need for external resistors, reduces BOM count, and achieves faster discharge (<1ms) than passive RC networks-critical for avoiding latch-up in downstream logic during power sequencing.

Can AP7343D-34W5-7 operate with input voltage below 1.7V?

No. Absolute minimum input voltage is 1.7V per datasheet specifications. Operation below this threshold risks regulation loss, increased dropout, and potential instability. For sub-1.7V applications (e.g., coin-cell powered sensors), consider Diodes' AP2204K-3.3 or Torex XC6206P series, which support down to 0.9V input.

How does thermal performance differ between SOT25 and X2-DFN1010-4 packages?

SOT25 offers 179°C/W θ_JA, while X2-DFN1010-4 (Type B) measures 237°C/W under JEDEC High-K board conditions. The SOT25's lower thermal resistance stems from its larger copper area and superior heat-spreading via the exposed pad-making it preferred for 300mA continuous loads in space-constrained layouts without forced airflow.