Diodes Incorporated AP7343-22FS4-7B

Overview

AP7343-22FS4-7B from Diodes Incorporated is a 300mA, 2.2V fixed-output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Built on CMOS process, it features enable control, thermal shutdown, and short-circuit protection, and is optimized for RF supply rails in space-constrained portable devices.

For engineers reviewing the AP7343-22FS4-7B datasheet, AP7343-22FS4-7B pinout, AP7343-22FS4-7B application, or AP7343-22FS4-7B equivalent, key selection criteria include dropout voltage at 300mA (0.22–0.29V), quiescent current (35µA typ), EN logic thresholds (0.5V low / 1.3V high), and X2-DFN1010-4 (Type B) thermal performance (R_θJA = 237°C/W).

Technical Context

The AP7343-22FS4-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor in a CMOS-based architecture. Its enable input controls regulator state with defined VIH/VIL thresholds, and internal thermal shutdown activates at +150°C with +20°C hysteresis.

It delivers stable 2.2V output across –40°C to +85°C ambient, supports input voltages from 1.7V to 5.25V, and maintains regulation under load transients up to 300mA with minimal output deviation-enabled by low-noise design and compatibility with 1µF ceramic output capacitors.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed thermal pad (EP) - requires PCB copper area connected to GND for optimal thermal dissipation (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 MCP1700-2202E/TO and XC6210B222MR-G, the AP7343-22FS4-7B provides superior PSRR and lower dropout in the smallest footprint, making it optimal for next-gen RF and imaging subsystems where noise, thermal density, and space are critical.

Availability

AP7343-22FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera module core supplies, wireless adapter SoC rails, and portable media player audio codec supplies requiring stable component supply, long-term manufacturability, and automotive-grade traceability options (via AP7343Q variant).

Supply support for AP7343-22FS4-7B 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 manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The AP7343 series targets portable and wireless systems requiring ultra-low-noise, high-PSRR LDOs in sub-1mm² packages - designed specifically for RF, imaging, and battery-sensitive consumer electronics.

FAQ

What is the minimum input voltage required for AP7343-22FS4-7B to maintain regulation at 300mA?

The minimum input voltage is 2.42V: calculated as V_OUT + V_DROP(max) = 2.2V + 0.29V. Below this, output voltage drops below specification. The device remains functional down to 1.7V input but cannot sustain 300mA load at 2.2V output below 2.42V.

Can the EN pin be left unconnected if enable functionality is not needed?

No - the EN pin must never be left floating. To ensure default ON operation, tie EN directly to VIN. Floating EN causes undefined regulator state and potential oscillation due to noise coupling, risking system instability or excessive power consumption.

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

Yes - a minimum 1µF ceramic capacitor is mandatory for stability and transient response. Place it within 2mm of VOUT and GND pins. For high-dynamic loads (e.g., burst-mode RF transmission), add a 4.7µF bulk capacitor in parallel to reduce peak voltage deviation.

Does AP7343-22FS4-7B include reverse-current protection or output discharge?

No - AP7343-22FS4-7B is the non-discharge variant (no "D" suffix). It lacks internal output discharge FET and does not block reverse current flow from VOUT to VIN. For applications requiring fast VOUT decay on shutdown, select AP7343D-22FS4-7B instead.