Diodes Incorporated AP7315D-15FS4-7B

Overview

AP7315D-15FS4-7B from Diodes Incorporated is a 150mA low-dropout linear regulator with fixed 1.5V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 35µA quiescent current. It features an enable pin, built-in discharge function, and operates from 1.7V to 5.25V input - optimized for RF supply rails in compact portable devices.

For engineers reviewing the AP7315D-15FS4-7B datasheet, AP7315D-15FS4-7B pinout, AP7315D-15FS4-7B application, or AP7315D-15FS4-7B equivalent, key selection criteria include dropout voltage at 150mA (max 0.64V for 1.5V output), thermal performance in X2-DFN1010-4 package, EN logic thresholds (0.5V low / 1.3V high), and discharge path resistance (30Ω typical).

Technical Context

The AP7315D-15FS4-7B integrates a CMOS-based error amplifier, precision voltage reference, current-limit circuit, and active discharge MOSFET. Its architecture enables fast load transient response (<100µs settling) and stable operation with 0.47µF ceramic input/output capacitors.

Unlike non-discharge variants (AP7315-15FS4-7B), this D-suffix version adds an internal NMOS discharge switch between VOUT and GND, activated during shutdown to rapidly deplete output capacitance - critical for sequencing-sensitive systems like multi-rail mobile SoCs.

Key Specifications

Pinout & Package

X2-DFN1010-4 (1.0mm × 1.0mm, 0.4mm pitch) exposes four terminals on bottom-side thermal pad; requires solder paste stencil optimization and GND-connected copper pour for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1502E/MB and XC6219B152MR-G, the AP7315D-15FS4-7B uniquely combines ±1% accuracy, integrated discharge, 75dB PSRR, and X2-DFN1010-4's 1.0mm² footprint - making it optimal for next-gen ultra-compact RF and imaging subsystems demanding tight regulation and controlled power-down.

Availability

AP7315D-15FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier bias, camera sensor core supply, and wireless adapter SoC I/O rail applications requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7315D-15FS4-7B 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 consumer, industrial, and automotive markets.

The AP7315 series belongs to Diodes' high-PSRR, low-noise LDO portfolio designed specifically for noise-sensitive RF, imaging, and portable communication applications where compact size and precise voltage regulation are critical.

FAQ

What is the purpose of the 'D' suffix in AP7315D-15FS4-7B?

The 'D' suffix denotes integrated active discharge functionality: when the EN pin is pulled low, an internal 30Ω NMOS switch connects VOUT to GND, rapidly discharging output capacitance. This eliminates reliance on external bleed resistors and ensures predictable power-down timing in multi-rail systems - confirmed in Electrical Characteristics (Note 10) and Typical Characteristics (pages 10–11).

Can AP7315D-15FS4-7B operate with input voltage below 1.7V?

No. The absolute minimum input voltage is 1.7V per Recommended Operating Conditions (page 4). Operation below this threshold risks regulation loss, increased dropout, and potential instability. At 1.5V input, the device cannot sustain 1.5V output due to inherent dropout - verified by Dropout Voltage vs. Output Current curves (page 7) showing >200mV drop even at light loads.

Is the X2-DFN1010-4 package thermally adequate for 150mA continuous operation?

Yes, when properly implemented: the thermal pad must be soldered to ≥40mm² GND copper pour (per JEDEC High-K board reference in Absolute Maximum Ratings). Under these conditions, the 400mW maximum power dissipation allows 150mA at 1.7V input (0.2V dropout = 30mW) - well within limits. Layout guidance is detailed in Application Information (page 11).

How does AP7315D-15FS4-7B differ from AP7315-15FS4-7B beyond discharge capability?

Both share identical electrical specs (accuracy, PSRR, noise, IQ), but only the 'D' variant includes the discharge FET. Pinout differs: AP7315-15FS4-7B uses Pin 4=VIN, Pin 1=VOUT, Pin 2=GND, Pin 3=EN; AP7315D-15FS4-7B uses same pin mapping but adds internal discharge path from Pin 1 to GND. No functional differences exist in enabled state - confirmed in Functional Block Diagram (page 3) and Ordering Information (page 12).