Diodes Incorporated AP7315-31SR-7

Overview

AP7315-31SR-7 from Diodes Incorporated is a 150mA low-dropout linear regulator with fixed 3.1V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, operates from 1.7V to 5.25V input, and is used in RF supply rails and portable media player core logic where stable low-noise voltage regulation is critical.

For engineers reviewing the AP7315-31SR-7 datasheet, AP7315-31SR-7 pinout, AP7315-31SR-7 application, or AP7315-31SR-7 equivalent, key selection criteria include dropout voltage at 150mA (max 0.29V for 3.1V output), EN logic thresholds (0.5V low / 1.3V high), thermal performance in SOT23-3, and compatibility with 0.47µF ceramic input/output capacitors.

Technical Context

The AP7315-31SR-7 implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, and current-limit protection. Its non-discharge design means the output remains floating during shutdown-no internal discharge path is present.

It delivers regulated 3.1V output from inputs as low as 1.7V, sustaining full 150mA load across –40°C to +85°C ambient. Line regulation is 0.02%/V and load regulation is 0.5%/A, enabling stable operation under dynamic load transients typical in handheld communication devices.

Key Specifications

Pinout & Package

AP7315-31SR-7 is packaged in SOT23-3 (SR variant), a 3-pin surface-mount package with 0.95mm pitch and exposed pad not connected internally. PCB layout requires short, low-impedance traces to VIN, VOUT, and GND pins, and thermal copper area connected to GND for dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-3102E/TT and XC6206P312MR-G, the AP7315-31SR-7 uniquely combines ultra-low noise, high PSRR, enable functionality, and SOT23-3 footprint-making it optimal for space-constrained, noise-critical portable RF and imaging applications.

Availability

AP7315-31SR-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, camera sensor core supply, wireless adapter baseband, and portable media player audio codec applications requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7315-31SR-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 high-reliability power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.

The AP7315 series belongs to Diodes' precision LDO portfolio, engineered specifically for battery-powered portable electronics demanding low noise, high PSRR, and minimal quiescent current in ultra-small packages.

FAQ

What is the maximum allowable input voltage for AP7315-31SR-7?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V may cause permanent damage or degrade long-term reliability, even if within absolute maximum ratings. For USB-powered designs, ensure input filtering clamps transients above 5.25V.

Does AP7315-31SR-7 include an internal discharge transistor?

No. AP7315-31SR-7 is the non-discharge variant (no "D" suffix). When disabled via the EN pin, the output floats and retains its voltage until discharged by external circuitry. This differs from AP7315D-31SR-7, which actively pulls VOUT to GND during shutdown.

Can AP7315-31SR-7 operate with ceramic output capacitors smaller than 0.47µF?

No. The datasheet specifies ≥0.47µF ceramic output capacitance for guaranteed stability and transient response. Using smaller values risks oscillation or excessive overshoot during load steps. X5R/X7R dielectrics with ≤10mΩ ESR are recommended; avoid high-ESR tantalum or aluminum electrolytics.

How does thermal performance differ between SOT23-3 and X2-DFN1010-4 packages?

SOT23-3 (SR) has θ_JA ≈ 250°C/W on standard JEDEC 2-layer board, limiting continuous 150mA operation above ~40°C ambient without copper pour. X2-DFN1010-4 offers θ_JA ≈ 180°C/W with thermal pad tied to GND plane-enabling full-rated current up to +85°C ambient in compact layouts.