Diodes Incorporated AP7348D-3328RS4-7

Overview

AP7348D-3328RS4-7 from Diodes Incorporated is a quad-channel, 300mA low-dropout linear regulator with independent enable control (EN1 for VOUT1/VOUT3; EN2 for VOUT2/VOUT4), ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). It delivers fixed 3.3V on Channel 1 & 3 and 2.8V on Channel 2 & 4, operating from 1.7V to 5.25V input, and is used in multi-rail power domains of camera modules and IoT communication subsystems.

For engineers reviewing the AP7348D-3328RS4-7 datasheet, AP7348D-3328RS4-7 pinout, AP7348D-3328RS4-7 application, or AP7348D-3328RS4-7 equivalent, this page provides verified functional partitioning, thermal shutdown behavior per channel, discharge circuit operation during disable, and package-specific layout guidance for X1-DFN1612-8 (Type B) mounting.

Technical Context

The AP7348D-3328RS4-7 integrates two independent voltage references and four CMOS-based LDO channels, each with dedicated error amplifiers, foldback current limiting, and auto-discharge circuits. Each channel features individual over-temperature sensing that disables only the affected channel under fault conditions.

Enable logic is split: EN1 controls VOUT1 and VOUT3 simultaneously; EN2 controls VOUT2 and VOUT4. When disabled, associated outputs actively discharge via internal 10Ω N-channel switches. Input voltage range (1.7V–5.25V) supports single-cell Li-ion and dual-cell alkaline/battery-backed systems.

Key Specifications

Pinout & Package

AP7348D-3328RS4-7 is housed in the X1-DFN1612-8 (Type B) package - a 1.6mm × 1.2mm, 0.4mm pitch, thermally enhanced DFN with exposed thermal pad. The package supports high-density PCB layouts and requires soldering the thermal pad for reliable thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6216D332MR-G and RT9080L-3328, AP7348D-3328RS4-7 uniquely combines quad-channel integration, 160µA IQ, 75dB PSRR, and per-channel thermal protection - making it optimal for space-constrained, noise-critical, and thermally demanding multi-rail embedded systems.

Availability

AP7348D-3328RS4-7 is available at Aetrix Electronics and suitable for smartphone camera modules, Wi-Fi access points, LPWAN sensor nodes, and industrial camera systems requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7348D-3328RS4-7 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 power management, signal integrity, and protection solutions for high-volume consumer, industrial, and automotive markets.

The AP7348 belongs to Diodes' high-PSRR, low-noise LDO family designed specifically for multi-rail portable electronics where simultaneous clean power delivery, sequencing flexibility, and thermal resilience are mandatory.

FAQ

What is the maximum allowable power dissipation for AP7348D-3328RS4-7?

The absolute maximum power dissipation is 600mW, as specified in the Absolute Maximum Ratings table. Exceeding this value triggers thermal shutdown at 155°C. At 85°C ambient and with the X1-DFN1612-8 (Type B) package, continuous 300mA per channel is achievable only if total power loss remains ≤600mW - requiring careful calculation of dropout voltage and load current per channel.

Does AP7348D-3328RS4-7 support output capacitor ESR outside the recommended range?

No. The device is optimized for low-ESR ceramic capacitors (≤10mΩ typical). Using higher-ESR capacitors risks instability and degraded transient response, as shown in the ESR vs. Output Current graph (DS42124 Rev. 3-2, p.10). Stable operation requires staying within the hatched region of that plot - exceeding 20mΩ at 300mA load is not guaranteed.

Can EN1 and EN2 be tied together for synchronous enable of all four channels?

Yes, EN1 and EN2 may be connected to the same logic signal to enable all four outputs simultaneously. However, doing so eliminates independent sequencing capability. Ensure the driving source meets both pins' input leakage (±1.0µA) and voltage thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V) under worst-case loading.

Is the thermal pad of AP7348D-3328RS4-7 electrically connected to GND internally?

No. The thermal pad is electrically isolated from all internal circuitry and may be left floating or connected to GND at the PCB level. Its sole purpose is thermal conduction; electrical connection to GND is optional and does not affect regulation performance, but improves heat transfer when soldered to a large copper pour.