Diodes Incorporated AP7343-33W5-7

Overview

AP7343-33W5-7 from Diodes Incorporated is a 300mA, 3.3V 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 portable wireless devices.

For engineers reviewing the AP7343-33W5-7 datasheet, AP7343-33W5-7 pinout, AP7343-33W5-7 application, or AP7343-33W5-7 equivalent, key selection criteria include its 35µA quiescent current, 0.22–0.29V dropout at 300mA (SOT25), EN logic thresholds (0.5V_IL/1.3V_IH), and compatibility with 1µF ceramic input/output capacitors.

Technical Context

The AP7343-33W5-7 integrates a precision voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor in a CMOS-based architecture. Its enable input directly controls the pass device gate, supporting fast turn-on/turn-off with <200µs response under 300mA load steps.

It delivers stable 3.3V regulation across 1.7V–5.25V input range with load regulation of ≤30mV (1mA–300mA) and line regulation of ≤0.1%/V. Thermal shutdown activates at +150°C with +20°C hysteresis, and short-circuit current is limited to ~55mA.

Key Specifications

Pinout & Package

AP7343-33W5-7 uses the SOT25 (SC-74A) 5-pin package - compact, surface-mount, and thermally enhanced with exposed pad connected to GND for improved heat dissipation (R_θJA = 179°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-3302E/TO and XC6210B332MR-G, AP7343-33W5-7 uniquely combines 300mA drive, 35µA IQ, ±1% accuracy, EN control, and thermal shutdown in SOT25-making it optimal for space-constrained, battery-powered RF systems requiring robustness and precision.

Availability

AP7343-33W5-7 is available at Aetrix Electronics and suitable for smartphone RF supplies, Wi-Fi module core rails, and portable camera ISP power delivery requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP7343-33W5-7 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 semiconductor company specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The AP7343 series targets portable and battery-powered electronics, delivering high-PSRR, low-noise LDOs optimized for RF, imaging, and audio subsystems where power efficiency and signal purity are critical.

FAQ

What is the minimum input voltage required for AP7343-33W5-7 to regulate 3.3V output at full 300mA load?

The minimum input voltage is determined by dropout: at 300mA and +25°C, dropout is 0.22V (typical) to 0.31V (max) in SOT25. Therefore, VIN must be ≥3.52V to guarantee regulation. At -40°C or +85°C, worst-case dropout reaches 0.39V, requiring VIN ≥3.69V for reliable operation across temperature.

Can AP7343-33W5-7 be used without an enable signal, and how should the EN pin be handled?

Yes-it can operate continuously by tying the EN pin directly to VIN. This configuration bypasses enable control but ensures the regulator remains active. Leaving EN floating is strictly prohibited, as it may cause erratic behavior or oscillation due to undefined logic state; a pull-up to VIN is the recommended default connection for always-on use.

Is the exposed pad (EP) on the SOT25 package electrically connected, and how should it be routed?

The exposed pad is internally connected to GND and serves as the primary thermal path. It must be soldered to a dedicated GND copper pour on the PCB-ideally ≥25 mm²-and connected to the main GND plane using ≥4 thermal vias (0.3mm diameter). Do not use the pad as a standalone GND electrode; it must be part of the system's low-impedance ground network to achieve rated R_θJA = 179°C/W.

How does AP7343-33W5-7 behave during output short-circuit, and what protection mechanisms activate?

Under VOUT-to-GND short, the AP7343-33W5-7 enters fold-back current limiting, clamping output current to ~55mA. Simultaneously, junction temperature rises; if it reaches +150°C, thermal shutdown disables the pass transistor. After cooldown (~20°C hysteresis), the device auto-restarts. No latch-up occurs, and recovery is fully automatic once fault is removed and temperature falls below +130°C.