Diodes Incorporated AP7315-135FS4-7B

Overview

AP7315-135FS4-7B from Diodes Incorporated is a 1.35V fixed-output, 150mA low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 35µA quiescent current - designed for RF supply rails in compact portable electronics.

For engineers reviewing the AP7315-135FS4-7B datasheet, AP7315-135FS4-7B pinout, AP7315-135FS4-7B application, or AP7315-135FS4-7B equivalent, this page delivers verified electrical specs, package mapping to X2-DFN1010-4, EN-controlled enable functionality, thermal pad layout guidance, and real-world use cases in camera modules and wireless adapters.

Technical Context

The AP7315-135FS4-7B implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, and current-limit circuitry. Its non-discharge output stage avoids automatic VOUT discharge during shutdown, preserving downstream capacitor charge.

It operates across 1.7V–5.25V input range and maintains regulation down to 210mV dropout at 150mA for 1.35V output. The EN pin accepts logic-level control (0–0.5V low, 1.3–5.25V high) with <1.0µA leakage, enabling precise power sequencing in multi-rail systems.

Key Specifications

Pinout & Package

AP7315-135FS4-7B uses the X2-DFN1010-4 (1.0mm × 1.0mm, 0.4mm pitch) package with wettable flank leads and an exposed thermal pad. PCB layout requires connection of the thermal pad to GND plane via multiple vias for thermal dissipation and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1302E/TT and XC6210B132MR-G, the AP7315-135FS4-7B uniquely balances 1.35V precision, 75dB PSRR, EN control, and DFN thermal performance - making it optimal for RF and imaging subsystems demanding simultaneous low noise, high rejection, and compact layout.

Availability

AP7315-135FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier bias, camera image sensor core supply, wireless adapter USB interface, and portable media player audio codec applications requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7315-135FS4-7B 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 semiconductor company specializing in discrete, analog, and mixed-signal devices, with design centers in Asia, Europe, and the U.S., and manufacturing in ISO/TS 16949-certified facilities.

The AP7315 series belongs to Diodes' high-performance LDO portfolio targeting battery-powered portable electronics - engineered for ultra-low noise, high PSRR, and minimal footprint in space- and power-sensitive applications.

FAQ

What is the maximum allowable input voltage for AP7315-135FS4-7B?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V may trigger internal protection or degrade long-term reliability, even if below the 6.0V absolute limit. Operation above 5.25V is not characterized or guaranteed per datasheet specifications.

Does AP7315-135FS4-7B include an output discharge function?

No - AP7315-135FS4-7B is the non-discharge variant (denoted by absence of "D" in part number). When disabled via EN pin, the output remains floating and retains charge on downstream capacitors. For active discharge, select AP7315D-135FS4-7B, which integrates a 30Ω NMOS discharge path.

Can AP7315-135FS4-7B be used with ceramic output capacitors smaller than 0.47µF?

The datasheet specifies 0.47µF as the minimum recommended value for stability across temperature and load. Using smaller values (e.g., 0.22µF) may cause marginal phase margin or degraded transient response, especially above 85°C or near 150mA load - validation with actual PCB layout and load profile is required.

How does the thermal pad on X2-DFN1010-4 affect power dissipation capability?

The exposed thermal pad increases power dissipation capability from ~150mW (no pad) to 400mW when properly connected to a 250mm² GND copper area with ≥4 thermal vias. Without thermal pad connection, junction temperature rise exceeds safe limits at >80mA continuous load, risking thermal shutdown or parametric drift.