Diodes Incorporated AP7315D-32W5-7

Overview

AP7315D-32W5-7 from Diodes Incorporated is a 3.2V fixed-output, 150mA low-dropout linear regulator with enable control, ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). It features low quiescent current (35µA typ), 0.21V typical dropout at 150mA, and integrated auto-discharge functionality for rapid VOUT discharge during shutdown - optimized for RF supply rails in portable wireless devices.

For engineers reviewing the AP7315D-32W5-7 datasheet, AP7315D-32W5-7 pinout, AP7315D-32W5-7 application, or AP7315D-32W5-7 equivalent, key selection criteria include its 3.2V fixed output, SOT25 package footprint, EN-controlled sequencing capability, discharge-enabled fast turn-off behavior, and suitability for noise-sensitive analog/RF subsystems requiring stable low-noise bias.

Technical Context

The AP7315D-32W5-7 employs a CMOS-based LDO architecture with internal voltage reference, error amplifier, current-limit circuitry, and NMOS pass transistor. Its enable input directly controls gate biasing of the pass device, while the integrated discharge FET (30Ω typical on-resistance) actively pulls VOUT to GND when EN is low.

Designed for high-PSRR, low-noise operation, it achieves 75dB ripple rejection at 1kHz and maintains stability with only 0.47µF ceramic input/output capacitors. The device operates across 1.7V–5.25V input range and supports full −40°C to +85°C ambient operation with ±30ppm/°C output voltage drift.

Key Specifications

Pinout & Package

SOT25 (5-pin, 2.9mm × 2.8mm × 1.3mm) package with exposed thermal pad. Pin 1 = VIN, Pin 2 = GND, Pin 3 = EN, Pin 4 = NC (no internal connection), Pin 5 = VOUT. Thermal pad must be connected to PCB ground plane for optimal thermal performance (θ_JA ≈ 180°C/W on JEDEC High-K board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7315-32W5-7, the D-version adds critical discharge functionality for safe multi-rail sequencing; versus MCP1700-3302E/TO, it trades slightly higher quiescent current for enable control, tighter accuracy, and lower noise - making it superior for RF and imaging subsystems.

Availability

AP7315D-32W5-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, camera sensor analog supply, wireless adapter core logic, and portable media player audio codec applications requiring stable component supply with guaranteed long-term availability.

Supply support for AP7315D-32W5-7 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-performance 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 noise-sensitive portable electronics requiring high PSRR, ultra-low noise, and fast enable/disable control - with emphasis on RF, imaging, and wireless connectivity subsystems.

FAQ

What is the purpose of the NC pin (Pin 4) in the SOT25 package?

Pin 4 is not connected internally and serves no electrical function. However, Diodes recommends connecting it to PCB ground to maximize copper area for thermal dissipation. This improves heat transfer from the die through the package's thermal pad and reduces junction temperature under load - critical for maintaining reliability at 150mA continuous output.

How does the auto-discharge feature affect system-level power sequencing?

The integrated 30Ω discharge FET actively pulls VOUT to GND within microseconds when EN is driven low, eliminating residual voltage that could cause latch-up or unintended operation in downstream circuits. This enables deterministic, glitch-free power-down sequencing in multi-rail systems - especially important when coordinating with PMICs or microcontrollers managing complex wake/sleep transitions.

Can AP7315D-32W5-7 operate with input voltage below 3.2V?

No - the minimum input voltage is 1.7V, but functional regulation requires VIN ≥ VOUT + dropout voltage. At 150mA, dropout is 0.21V (typ), so VIN must be ≥ 3.41V to maintain 3.2V output. Below this, output voltage drops linearly with input; operation below 3.2V input is only valid for partial-load or pre-bias conditions where regulation is not required.

Why is a 0.47µF ceramic capacitor specified for both CIN and COUT?

The AP7315D-32W5-7's internal compensation is optimized for stability with low-ESR ceramic capacitors ≥0.47µF. Smaller values risk oscillation due to insufficient phase margin; larger values improve transient response but offer diminishing returns. Placement within 2mm of VIN/GND and VOUT/GND pins is mandatory to minimize parasitic inductance and ensure robust high-frequency stability.