Diodes Incorporated AP7343D-19W5-7

Overview

AP7343D-19W5-7 from Diodes Incorporated is a 300mA, 1.9V fixed-output low-dropout linear regulator with high PSRR (75dB at 1kHz), ultra-low output noise (60µVrms), ±1% output voltage accuracy, and enable-controlled shutdown. It operates from 1.7V to 5.25V input and delivers stable power to noise-sensitive RF supplies and portable media subsystems.

For engineers reviewing the AP7343D-19W5-7 datasheet, AP7343D-19W5-7 pinout, AP7343D-19W5-7 application, or AP7343D-19W5-7 equivalent, key selection criteria include its 35µA quiescent current, 0.22–0.29V dropout at 300mA (for 1.9V output), integrated auto-discharge function, and SOT25 package thermal performance (θ_JA = 179°C/W).

Technical Context

The AP7343D-19W5-7 implements a CMOS-based LDO architecture with internal voltage reference, error amplifier, current-limit circuit, and thermal shutdown. Its enable input (EN) provides precise on/off control with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V) and sub-1µA standby leakage.

It features built-in discharge functionality (denoted by "D" in part number), actively pulling VOUT to GND during shutdown via a 30Ω internal N-channel switch. This eliminates residual output voltage and prevents back-powering of downstream circuitry-critical for multi-rail portable systems requiring clean power sequencing.

Key Specifications

Pinout & Package

AP7343D-19W5-7 is packaged in the SOT25 (SC-74A) 5-pin surface-mount package, optimized for thermal performance (θ_JA = 179°C/W) and board space efficiency in portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1804T-1902I/OT and XC6219B192MR-G, AP7343D-19W5-7 uniquely combines 300mA drive, 35µA quiescent current, and integrated discharge-enabling robust, sequenced power management in space-constrained portable systems without added components.

Availability

AP7343D-19W5-7 is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera ISP powering, portable media audio codec supply, and wireless adapter baseband core regulation requiring stable component supply, automotive-grade reliability derivatives (AP7343Q), and RoHS-compliant green packaging.

Supply support for AP7343D-19W5-7 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 consumer, industrial, computing, and communications markets.

The AP7343 series belongs to Diodes' high-performance LDO portfolio, designed specifically for battery-powered portable electronics demanding ultra-low noise, high PSRR, and intelligent power sequencing capabilities.

FAQ

What is the purpose of the NC pin (Pin 5) in the SOT25 package?

Pin 5 is a no-connect terminal with no internal bond wire or circuit connection. It serves a mechanical role-improving package rigidity and solder joint reliability-but carries no electrical function. It may be left floating or connected to GND for thermal or layout consistency; doing so does not affect regulation or enable behavior.

Does AP7343D-19W5-7 require an external pull-up resistor on the EN pin?

No external pull-up is required. The EN pin has no internal pull-up; however, it must never be left floating. If enable control is unused, tie EN directly to VIN to maintain continuous operation. Driving EN from a microcontroller GPIO is safe-its input leakage is ±1.0µA, and thresholds (0–0.5V low, 1.3–5.25V high) align with standard 1.8V/3.3V logic levels.

How does the auto-discharge feature impact output capacitor selection?

The internal 30Ω discharge FET allows rapid VOUT decay (τ ≈ R×C), reducing hold-up time after shutdown. For a typical 10µF output capacitor, discharge completes in <300µs. This eliminates need for external bleed resistors, but designers should verify that fast discharge doesn't induce unintended reset events in downstream logic-especially when sharing VOUT with other LDO inputs.

Can AP7343D-19W5-7 operate with only a 0.47µF input capacitor?

Yes-the datasheet specifies a minimum 0.47µF ceramic capacitor between VIN and GND. This suffices for most portable applications with localized power distribution. However, if the input source exhibits high impedance or long trace inductance (e.g., >10cm from bulk capacitor), adding a 4.7–10µF tantalum or polymer cap upstream improves transient immunity and prevents VIN droop during large load steps.