Diodes Incorporated AP7315-18W5-7

Overview

AP7315-18W5-7 from Diodes Incorporated is a 150mA low-dropout linear regulator with fixed 1.8V 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 optimized for RF supply rails in portable wireless communication devices.

For engineers reviewing the AP7315-18W5-7 datasheet, AP7315-18W5-7 pinout, AP7315-18W5-7 application, or AP7315-18W5-7 equivalent, this page delivers verified electrical parameters, SOT25 package layout guidance, real-world load transient behavior, and validated alternative LDOs for power-sensitive handheld designs.

Technical Context

The AP7315-18W5-7 uses a CMOS-based architecture with integrated voltage reference, error amplifier, and current-limit circuitry. Its enable input (EN) provides precise on/off control with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V), and it lacks internal discharge functionality (non-discharge variant).

Designed for low-noise analog and RF subsystems, it maintains stable regulation under fast load transients (e.g., 50mA ↔ 150mA steps) and achieves <290mV dropout at 150mA for V_OUT = 1.8V. Thermal performance relies on PCB copper area connected to the exposed thermal pad (not used as GND electrode).

Key Specifications

Pinout & Package

SOT25 (5-pin) package with exposed thermal pad (not electrically connected); requires large PCB copper area tied to GND for thermal dissipation. Pin 4 is NC (not connected internally) and should be grounded for optimal thermal performance.

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 AP7315-18W5-7 uniquely combines 150mA drive capability, 75dB PSRR, enable control, and 35µA I_Q in a 5-pin SOT25 footprint-making it the only choice for compact, noise-critical, and sequenced-power wireless subsystems.

Availability

AP7315-18W5-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, wireless SoC core supply, and camera sensor interface applications requiring stable component supply, consistent parametric performance across temperature, and long-term production continuity.

Supply support for AP7315-18W5-7 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 solutions 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 RF, imaging, and portable communication systems where clean, efficient, and controllable voltage regulation is critical.

FAQ

What is the maximum allowable input voltage for AP7315-18W5-7?

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 overvoltage protection or cause permanent damage. For battery-powered designs, this range accommodates fully charged single-cell Li-ion (up to 4.2V) and regulated 5V rails.

Does AP7315-18W5-7 include an output discharge function?

No, AP7315-18W5-7 is the non-discharge variant (no "D" suffix). When disabled via the EN pin, the output remains floating and does not actively pull VOUT to GND. If rapid output discharge is required-for example, to meet system-level reset timing-AP7315D-18W5-7 (discharge version) must be selected instead.

Can AP7315-18W5-7 operate with ceramic capacitors smaller than 0.47µF?

No-the datasheet specifies a minimum 0.47µF ceramic capacitor on both input (CIN) and output (COUT) for stability and transient response. Using smaller values risks oscillation, poor load step recovery, or increased output ripple. The device is optimized for low-ESR ceramics; tantalum or aluminum electrolytics are not recommended due to higher ESR and aging effects.

How is thermal performance affected by the NC pin (Pin 4) in SOT25?

Pin 4 is not connected internally but serves as a thermal relief point. Connecting it to GND maximizes PCB copper area coverage over the thermal pad, improving heat conduction away from the die. Leaving it unconnected reduces thermal resistance by ~15°C/W versus floating; tying to GND yields best-case junction-to-ambient performance in standard JEDEC 2-layer board layouts.