Diodes Incorporated AP7343D-23FS4-7B

Overview

AP7343D-23FS4-7B from Diodes Incorporated is a 300mA, 2.3V fixed-output low-dropout linear regulator with high PSRR (75dB at 1kHz), ultra-low output noise (60µVrms, 10Hz–100kHz), ±1% output voltage accuracy, and enable-controlled shutdown. Fabricated on a CMOS process, it delivers stable power to RF supplies and camera modules in space-constrained portable devices using the X2-DFN1010-4 (Type B) package.

For engineers reviewing the AP7343D-23FS4-7B datasheet, AP7343D-23FS4-7B pinout, AP7343D-23FS4-7B application, or AP7343D-23FS4-7B equivalent, key selection criteria include dropout voltage at 300mA (0.35V typ. for 2.3V VOUT), thermal resistance (θJA = 237°C/W), EN logic thresholds (0.5V max low, 1.3V min high), and built-in discharge functionality enabled by the "D" suffix.

Technical Context

The AP7343D integrates a precision voltage reference, error amplifier, current-limit circuit, and thermal shutdown protection. Its CMOS-based architecture enables low quiescent current (35µA typ.) and fast load transient response without requiring external compensation.

Unlike standard LDOs, the "D" variant includes an internal N-channel MOSFET (RON ≈ 30Ω) between VOUT and GND for active output discharge during shutdown - critical for systems requiring rapid rail collapse and sequencing compliance. The device operates across 1.7V–5.25V input and guarantees 300mA output up to +85°C ambient.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed pad (EP) for thermal enhancement. Not electrically connected - must be soldered to GND plane for optimal thermal dissipation (θ_JB = 85.7°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-2302E/TO and XC6219B232MR-G, the AP7343D-23FS4-7B uniquely combines discharge capability, 75dB PSRR, and 1.0mm² footprint - making it optimal for miniaturized RF and imaging subsystems demanding strict power sequencing and noise control.

Availability

AP7343D-23FS4-7B is available at Aetrix Electronics and suitable for RF power amplifiers, CMOS image sensors, portable audio codecs, and wireless adapter baseband ICs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7343D-23FS4-7B 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 ICs for power management, signal integrity, and connectivity applications.

The AP7343 series targets portable and battery-powered systems needing ultra-low-noise, high-PSRR, and enable-controlled LDOs - with variants optimized for space-constrained layouts and stringent sequencing requirements.

FAQ

What is the purpose of the exposed pad (EP) on the X2-DFN1010-4 package?

The exposed pad is a thermal interface, not an electrical terminal. It must be soldered to a PCB ground plane covering ≥4mm² to achieve the specified θ_JA = 237°C/W. Leaving it unconnected raises junction temperature by >25°C at 300mA, risking thermal shutdown.

Does the "D" in AP7343D-23FS4-7B indicate a different output voltage or a functional variant?

The "D" denotes the discharge variant: it integrates a 30Ω N-channel FET between VOUT and GND that activates when EN is low, discharging the output capacitor in <100µs. Output voltage remains fixed at 2.3V - identical to non-D versions.

Can AP7343D-23FS4-7B operate with only a 0.47µF input capacitor?

Yes - the datasheet specifies a minimum 0.47µF ceramic capacitor between VIN and GND. For optimal transient immunity, place it within 1mm of PIN4 and GND. Larger values (≥1µF) further reduce input impedance but are not required for stability.

How does the AP7343D's PSRR performance change with load current?

PSRR remains ≥75dB at 1kHz from 1mA to 150mA load; it degrades to ~65dB at 300mA due to increased error amplifier loading. For noise-sensitive loads, maintain I_OUT ≤150mA or add a second-stage RC filter if full 300mA is required.