Diodes Incorporated AP7315-18SR-7

Overview

AP7315-18SR-7 from Diodes Incorporated is a 150mA low-dropout linear regulator with fixed 1.8V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µVrms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, operates from 1.7V to 5.25V input, and is optimized for RF supply rails in compact portable devices.

For engineers reviewing the AP7315-18SR-7 datasheet, AP7315-18SR-7 pinout, AP7315-18SR-7 application, or AP7315-18SR-7 equivalent, key selection criteria include dropout voltage at 150mA (max 0.34V for 1.7V ≤ VOUT < 2.0V), thermal performance in SOT23-3 package, EN logic thresholds (0.5V low / 1.3V high), and compatibility with 0.47µF ceramic input/output capacitors.

Technical Context

The AP7315-18SR-7 uses a CMOS-based LDO architecture with integrated voltage reference, error amplifier, and current-limit circuitry. Its enable input directly controls NMOS pass transistor gate, allowing fast turn-on/turn-off with no discharge path (non-discharge variant).

It delivers stable 1.8V output under load transients up to 150mA while maintaining 75dB ripple rejection at 1kHz and 60µVrms broadband noise - critical for noise-sensitive RF and camera power domains. Dropout voltage is specified at 2% VOUT deviation, with typical 280mV at 150mA and 25°C for this 1.8V version.

Key Specifications

Pinout & Package

SOT23-3 (SR) package: ultra-compact 2.9mm × 1.6mm footprint with 0.95mm height; thermally enhanced for 400mW power dissipation in ambient air.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and XC6206P182MR-G, the AP7315-18SR-7 uniquely balances 150mA output, 75dB PSRR, and 60µVrms noise in the same SOT23-3 footprint - making it the only option qualified for noise-critical RF and imaging subsystems without sacrificing board space.

Availability

AP7315-18SR-7 is available at Aetrix Electronics and suitable for RF power supplies, camera sensor biasing, portable media decoders, and wireless adapter core regulation requiring stable component supply across high-mix consumer electronics production.

Supply support for AP7315-18SR-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 company specializing in discrete, analog, and mixed-signal ICs for power management, signal integrity, and connectivity applications.

The AP7315 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive portable communication equipment including smartphones, tablets, and wireless peripherals.

FAQ

What is the maximum allowable input voltage for AP7315-18SR-7?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V risks violating safe operating area limits and may trigger internal protection or cause permanent damage. For long-term reliability, maintain VIN ≤ 5.25V under all conditions including transient spikes.

Does AP7315-18SR-7 include an output discharge function?

No, AP7315-18SR-7 is the non-discharge variant (suffix "-" not "D"). When disabled via EN pin, the output remains floating and retains charge on downstream capacitance. If rapid VOUT discharge is required, select AP7315D-18SR-7, which integrates a 30Ω NMOS discharge switch between VOUT and GND.

Can AP7315-18SR-7 operate with ceramic output capacitors smaller than 0.47µF?

No - the device is optimized for stability with ≥0.47µF ceramic capacitors having low ESR (≤10mΩ). Using smaller values risks oscillation or degraded transient response. The datasheet explicitly specifies 0.47µF as minimum; 1µF is recommended for improved load-step immunity in high-dynamic applications like camera autofocus bursts.

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

The SOT23-3 (SR) has θ_JA ≈ 250°C/W on standard JEDEC 2-layer board, while X2-DFN1010-4 achieves ≈ 180°C/W due to its exposed thermal pad. At 150mA and 1.7V dropout, SR package junction temperature rise is ~64°C above ambient - acceptable up to +85°C ambient. DFN offers 25% lower thermal resistance for higher ambient or sustained load scenarios.