Diodes Incorporated AP7343D-17W5-7

Overview

AP7343D-17W5-7 from Diodes Incorporated is a 300mA low-dropout linear regulator with fixed 1.7V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µVrms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, thermal shutdown, short-circuit protection, and is optimized for RF supply rails in space-constrained portable devices using the SOT25 package.

For engineers reviewing the AP7343D-17W5-7 datasheet, AP7343D-17W5-7 pinout, AP7343D-17W5-7 application, or AP7343D-17W5-7 equivalent, key selection criteria include dropout voltage at 300mA (0.30–0.41V), EN logic thresholds (0.5V low / 1.3V high), thermal resistance (179°C/W), and discharge functionality enabled by the "D" suffix.

Technical Context

The AP7343D-17W5-7 integrates a CMOS-based pass transistor, precision voltage reference, error amplifier, current-limit circuit, and thermal shutdown. Its enable input supports active-high logic control with defined VIH/VIL thresholds and sub-1µA standby current when disabled.

It delivers regulated 1.7V output across input voltages from 1.7V to 5.25V, maintaining stability with ≥1µF ceramic output capacitance. The built-in auto-discharge function (indicated by "D") actively pulls VOUT to GND during shutdown, preventing floating rail conditions in multi-rail systems.

Key Specifications

Pinout & Package

AP7343D-17W5-7 is housed in the SOT25 (SC-74A) 5-pin surface-mount package - compact (2.9mm × 1.6mm × 1.1mm), thermally enhanced, and compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1702E/TT and XC6210B172MR-G, the AP7343D-17W5-7 uniquely combines 300mA capability, ±1% accuracy, 75dB PSRR, and integrated auto-discharge in the industry-standard SOT25 footprint - making it optimal for battery-powered RF and imaging subsystems requiring precise, sequenced, low-noise regulation.

Availability

AP7343D-17W5-7 is available at Aetrix Electronics and suitable for smartphone RF supplies, portable camera sensor bias, wireless headset audio codecs, and BLE SoC I/O domains requiring stable component supply, long-term lifecycle assurance, and automotive-grade traceability options (via AP7343Q variant).

Supply support for AP7343D-17W5-7 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 manufacturer 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 noise-sensitive, battery-operated portable electronics demanding ultra-low I_Q, fast transient response, and robust protection in minimal footprints.

FAQ

What is the purpose of the "D" suffix in AP7343D-17W5-7?

The "D" denotes integrated auto-discharge functionality: when the EN pin is pulled low, an internal N-channel MOSFET actively discharges the VOUT capacitor to GND within microseconds. This prevents back-powering of upstream circuitry, eliminates floating rail states during power-down sequencing, and reduces system-level leakage current - critical for multi-rail portable devices.

Can AP7343D-17W5-7 operate with input voltage equal to its 1.7V output?

No - the absolute minimum input voltage is 1.7V, but functional regulation requires headroom above VOUT. At 300mA load, dropout is 0.30–0.41V (SOT25), so VIN must be ≥2.0V to maintain 1.7V output. Operation at VIN = VOUT is only possible at near-zero load currents and is not guaranteed across temperature or process variation.

Is an external output capacitor mandatory, and what type is recommended?

Yes - a minimum 1µF ceramic capacitor is required between VOUT and GND for stability and transient response. X5R or X7R dielectrics are recommended for temperature stability. Place it within 2mm of the VOUT and GND pins using short, wide traces. Bulk capacitance (e.g., 4.7µF) improves large-step load transient recovery but does not replace the essential 1µF ceramic.

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

The SOT25 package has R_θJA = 179°C/W, while the X2-DFN1010-4 (Type B) measures 237°C/W under JEDEC High-K board conditions. Though the DFN offers smaller area, its higher junction-to-ambient resistance means greater temperature rise at identical power dissipation. For 300mA loads near VIN = 5.25V, SOT25 provides superior thermal margin in constrained layouts without added copper area.