Diodes Incorporated AP7315D-185W5-7

Overview

AP7315D-185W5-7 from Diodes Incorporated is a 150mA low-dropout linear regulator with fixed 1.85V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µVrms output noise (10Hz–100kHz), and 35µA quiescent current. It features an enable input, built-in discharge function, and operates from 1.7V to 5.25V input - optimized for RF supply rails in portable wireless communication devices.

For engineers reviewing the AP7315D-185W5-7 datasheet, AP7315D-185W5-7 pinout, AP7315D-185W5-7 application, or AP7315D-185W5-7 equivalent, key selection criteria include dropout voltage at 150mA (max 0.44V for 1.85V output), EN logic thresholds (0.5V low / 1.3V high), thermal performance in SOT25, and discharge path resistance (30Ω typical).

Technical Context

The AP7315D-185W5-7 integrates a CMOS-based error amplifier, precision voltage reference, current-limit circuit, and active discharge FET. Its architecture enables fast load transient response (<100µs settling) and stable operation with 0.47µF ceramic input/output capacitors.

Unlike non-discharge variants (e.g., AP7315-185W5-7), the "D" suffix denotes an internal NMOS discharge switch (30Ω typical) that actively pulls VOUT to GND when EN is low - eliminating residual voltage hold-up and enabling precise power sequencing in multi-rail systems.

Key Specifications

Pinout & Package

SOT25 package (5-pin, 2.9mm × 1.6mm × 1.1mm) with exposed thermal pad. Optimized for compact PCB layouts and thermal dissipation via PCB copper area connected to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and XC6210B185MR-G, the AP7315D-185W5-7 uniquely combines 150mA delivery, ±1% accuracy, 75dB PSRR, and integrated discharge in SOT25 - making it optimal for space-constrained, sequenced RF and imaging subsystems requiring both precision and clean power-down.

Availability

AP7315D-185W5-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, camera sensor core supply, wireless adapter SoC I/O rails, and portable media player audio codec applications requiring stable component supply across production lifecycles.

Supply support for AP7315D-185W5-7 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 manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and protection solutions for high-volume consumer, industrial, and automotive markets.

The AP7315 series belongs to Diodes' high-PSRR, low-noise LDO portfolio designed specifically for noise-sensitive analog and RF subsystems in portable electronics - emphasizing small footprint, fast transient response, and robust sequencing capability.

FAQ

What is the purpose of the NC pin (Pin 4) in the SOT25 package?

Pin 4 is internally not connected and serves no electrical function. Diodes Incorporated recommends connecting it to PCB ground to maximize copper area for thermal dissipation - this improves heat transfer from the thermal pad without introducing unintended current paths or noise coupling.

Does the AP7315D-185W5-7 require an external discharge resistor?

No. The "D" suffix indicates an integrated NMOS discharge transistor (30Ω typical on-resistance) that automatically sinks VOUT to GND when EN is low. No external components are needed for discharge - simplifying layout and ensuring consistent discharge timing across temperature and process variation.

Can the AP7315D-185W5-7 operate with input voltage below 1.85V?

No. The minimum input voltage is 1.7V per specification, but functional regulation requires VIN ≥ VOUT + dropout voltage. At 150mA, dropout is up to 0.44V, so VIN must be ≥ 2.29V to maintain 1.85V output. Below that, output collapses and regulation is lost.

How does the active discharge affect power sequencing in multi-rail systems?

The 30Ω discharge path pulls VOUT to GND in under 1ms after EN deactivation, preventing back-powering of upstream regulators or leakage into powered-down domains. This enables deterministic, repeatable power-down timing - essential for meeting JEDEC JESD78 latch-up immunity and USB suspend/resume specifications.