Diodes Incorporated AP7353-32FS4-7

Overview

AP7353-32FS4-7 from Diodes Incorporated is a 250mA low-dropout linear regulator with fixed 3.2V output, ±1% accuracy, 90dB PSRR at 1kHz, 10µV_rms output noise (10Hz–100kHz), and 18µA typical quiescent current. It features enable control, thermal shutdown, and short-circuit protection, and is optimized for RF supply rails and battery-powered portable electronics.

For engineers reviewing the AP7353-32FS4-7 datasheet, AP7353-32FS4-7 pinout, AP7353-32FS4-7 application, or AP7353-32FS4-7 equivalent, key selection criteria include dropout voltage at 250mA (≤150mV), EN logic thresholds (0.4V low / 1.2V high), thermal resistance (237°C/W), and compatibility with 1µF ceramic output capacitors in space-constrained layouts.

Technical Context

The AP7353-32FS4-7 implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, and current-limit circuitry. Its non-discharge configuration avoids automatic output discharge during shutdown, preserving downstream capacitor charge.

It operates across 2.0V–5.5V input range and maintains regulation down to 3.2V output with ≤150mV dropout at full 250mA load. Fast load transient response (<20µs) and stable operation with 0.7µF–1µF X7R/X5R ceramic capacitors support dynamic RF and digital core supply requirements.

Key Specifications

Pinout & Package

AP7353-32FS4-7 uses the X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed pad (EP) for thermal dissipation. Recommended PCB layout uses large copper area connected to GND under EP.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-3202E/MB and XC6210B322MR-G, AP7353-32FS4-7 delivers superior noise suppression (10µV_rms vs. ≥25µV_rms) and higher PSRR across 1–10kHz, making it optimal for RF and high-fidelity analog signal chains where supply integrity directly impacts SNR.

Availability

AP7353-32FS4-7 is available at Aetrix Electronics and suitable for smartphone camera modules, wireless audio earbuds, and portable medical sensor hubs requiring stable component supply with guaranteed long-term sourcing.

Supply support for AP7353-32FS4-7 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 AP7353 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive applications in portable communications and imaging systems where supply rail purity directly impacts system-level performance.

FAQ

What is the minimum input voltage required to maintain 3.2V output at 250mA?

The AP7353-32FS4-7 requires a minimum input voltage of 3.35V to sustain 3.2V output at full 250mA load, based on its maximum dropout voltage of 150mV per datasheet Section 4 (Electrical Characteristics). At lighter loads, VIN can be reduced further-e.g., 3.25V suffices at 100mA where dropout drops to ~60mV.

Can the EN pin be left unconnected if always-on operation is desired?

No-the EN pin must never be left floating. For always-on operation, tie EN directly to the IN pin. This ensures the enable threshold (≥1.2V) is met across the full operating temperature and input voltage range, preventing unintended shutdown due to leakage or noise coupling.

Is an output capacitor mandatory, and what type is recommended?

Yes-an output capacitor is mandatory for stability and transient response. Diodes specifies 1µF X7R or X5R ceramic capacitors with ESR <2Ω. The device remains stable down to 0.7µF, but 1µF is recommended to accommodate capacitance loss from DC bias and temperature drift in production environments.

Does AP7353-32FS4-7 include reverse-current protection?

No-the AP7353-32FS4-7 does not integrate reverse-current protection. When input voltage falls below output voltage (e.g., during input brownout), current can flow backward from OUT to IN through the internal pass FET body diode. External protection (e.g., series Schottky) is required if reverse conduction must be blocked.