Diodes Incorporated AP7343D-31W5-7

Overview

AP7343D-31W5-7 from Diodes Incorporated is a 300mA, 3.1V fixed-output low-dropout linear regulator with high PSRR (75dB at 1kHz), ultra-low output noise (60µV_rms, 10Hz–100kHz), ±1% output voltage accuracy, and enable-controlled shutdown. Built on CMOS process, it delivers stable power to RF supplies and camera modules in space-constrained portable devices using its SOT25 package.

For engineers reviewing the AP7343D-31W5-7 datasheet, AP7343D-31W5-7 pinout, AP7343D-31W5-7 application, or AP7343D-31W5-7 equivalent, key selection criteria include its 35µA quiescent current, 0.22–0.29V dropout at 300mA (for 3.1V output), integrated thermal shutdown (+150°C), and discharge function enabled by the 'D' suffix - critical for rapid VOUT discharge during shutdown in battery-powered systems.

Technical Context

The AP7343D-31W5-7 implements a CMOS-based LDO architecture with internal voltage reference, error amplifier, current limit circuit, and thermal shutdown protection. Its enable input (EN) provides precise on/off control with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V), and the 'D' variant integrates an N-channel auto-discharge transistor (R_ON ≈ 30Ω) between VOUT and GND when disabled.

It operates across 1.7V–5.25V input range and maintains regulation down to 300mA load with <±30ppm/°C output voltage drift over –40°C to +85°C ambient. The SOT25 package delivers θ_JA = 179°C/W and supports fast transient response due to low output impedance and compatibility with 1µF ceramic output capacitors.

Key Specifications

Pinout & Package

AP7343D-31W5-7 is packaged in the SOT25 (SC-74A) 5-pin surface-mount package - a compact, thermally enhanced leaded package with exposed pad for improved heat dissipation. Pin 1 is VIN, Pin 2 is GND, Pin 3 is EN, Pin 4 is VOUT, and Pin 5 is NC (no connection). The exposed pad (EP) must be connected to PCB ground plane for optimal thermal performance but is not electrically tied to internal GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703-3102E/MB and XC6210B312MR-G, the AP7343D-31W5-7 uniquely combines ±1% accuracy, 75dB PSRR, 60µV_rms noise, and integrated 30Ω discharge - making it optimal for battery-powered RF and imaging systems requiring both precision regulation and controlled power-down behavior.

Availability

AP7343D-31W5-7 is available at Aetrix Electronics and suitable for smartphone camera modules, RF transceiver bias supplies, portable media player audio codecs, and wireless headset MCU core supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP7343D-31W5-7 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 belongs to Diodes' high-performance LDO portfolio, engineered specifically for low-power portable electronics demanding ultra-low noise, high PSRR, and fast enable/disable control in minimal footprints.

FAQ

What is the purpose of the 'D' suffix in AP7343D-31W5-7?

The 'D' denotes integrated auto-discharge functionality: when the EN pin is pulled low, an internal 30Ω N-channel MOSFET connects VOUT to GND, rapidly discharging output capacitance. This prevents residual voltage from interfering with downstream logic states or causing unintended wake-up events in battery-powered systems.

Can AP7343D-31W5-7 operate from a 3.0V input while delivering 3.1V output?

No - the device requires VIN ≥ VOUT + dropout voltage. At 300mA load and 3.1V output, dropout is 0.22–0.31V (SOT25), so minimum VIN is ~3.32V. It is not suitable for 3.0V input; instead, use a lower-VOUT variant (e.g., 2.8V) or boost converter upstream.

Is the NC pin (Pin 5) required to be grounded?

No - Pin 5 is internally unconnected. It may be left floating or tied to GND for mechanical reinforcement, but it serves no electrical function. Do not route signals or power through it, as it has no internal connection to the die.

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

SOT25 offers θ_JA = 179°C/W, while X2-DFN1010-4 achieves 237°C/W on standard JEDEC boards - meaning SOT25 dissipates heat more effectively in typical layouts. However, X2-DFN1010-4's smaller footprint (1.0mm × 1.0mm) suits ultra-dense designs where board area outweighs thermal margin.