Diodes Incorporated AP7348D-3330RS4-7

Overview

AP7348D-3330RS4-7 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 channels 1 & 3 and 3.0V on channels 2 & 4, operating from 1.7V to 5.25V input, and is optimized for RF supply in IoT/LPWAN modules where low noise and high PSRR are critical.

For engineers reviewing the AP7348D-3330RS4-7 datasheet, AP7348D-3330RS4-7 pinout, AP7348D-3330RS4-7 application, or AP7348D-3330RS4-7 equivalent, this device supports simultaneous dual-rail power delivery with thermal shutdown per channel, foldback current limiting, and auto-discharge-key for battery-powered communication modules requiring fast enable/disable response and rail isolation.

Technical Context

The AP7348D-3330RS4-7 integrates two independent CMOS-based LDO regulators per enable input: EN1 controls VOUT1 (3.3V) and VOUT3 (3.3V); EN2 controls VOUT2 (3.0V) and VOUT4 (3.0V). Each channel features dedicated error amplifiers, foldback current limiting (55mA short-circuit clamp), and thermal shutdown at +155°C with +25°C hysteresis.

It uses a single VDD input (1.7–5.25V) and shares ground across all channels, with separate discharge paths activated during disable. The X1-DFN1612-8 (Type B) package includes an exposed thermal pad electrically isolated but thermally coupled, enabling 160°C/W junction-to-ambient thermal resistance under JEDEC High-K board conditions.

Key Specifications

Pinout & Package

X1-DFN1612-8 (Type B) package: 1.6mm × 1.2mm footprint, 0.4mm pitch, 0.39mm nominal height, with exposed thermal pad (electrically isolated, recommended to connect to GND for thermal performance).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6216D333MR-G and RT9080L-3330, the AP7348D-3330RS4-7 uniquely combines dual-rail enable control, per-channel thermal protection, and industry-leading 75dB PSRR-making it the only solution that meets simultaneous low-noise, multi-rail sequencing, and battery-life requirements in space-constrained IoT endpoints.

Availability

AP7348D-3330RS4-7 is available at Aetrix Electronics and suitable for LPWAN sensor nodes, Wi-Fi 6E modules, smartphone camera subsystems, and RF transceiver power delivery requiring stable component supply across automotive-grade temperature ranges (−40°C to +85°C).

Supply support for AP7348D-3330RS4-7 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 communications markets.

The AP7348 belongs to Diodes' high-PSRR, low-noise LDO family designed specifically for noise-sensitive RF and mixed-signal applications-including IoT connectivity, wireless infrastructure, and portable imaging-where rail isolation and fast transient response are mandatory.

FAQ

What is the maximum allowable power dissipation for AP7348D-3330RS4-7?

The absolute maximum power dissipation is 600mW, as specified in the Absolute Maximum Ratings table. Exceeding this limit triggers thermal shutdown at +155°C. In practice, continuous operation above 600mW is prohibited-even briefly-as it causes output voltage instability and may reduce long-term reliability. Designers must calculate worst-case power (P_D = Σ(V_IN − V_OUT) × I_OUT) and verify junction temperature remains below 155°C using θ_JA = 160°C/W.

Can EN1 and EN2 be tied together for simultaneous control of all four channels?

Yes-EN1 and EN2 can be connected to a common GPIO, enabling or disabling all four outputs simultaneously. However, doing so forfeits independent rail control: VOUT1/VOUT3 and VOUT2/VOUT4 will always power up/down together. This configuration is valid for applications requiring simple on/off control, but invalidates use cases needing staggered sequencing (e.g., camera module power-up order) or partial rail retention during sleep modes.

Is the thermal pad electrically connected to GND internally?

No-the thermal pad is electrically isolated from all internal circuitry and pins. It must be externally connected to PCB ground for optimal thermal performance, but it may also be left floating or connected to a separate thermal plane if electrical isolation is required. Pin 1 (GND) remains the sole electrical ground reference; omitting its connection will cause functional failure regardless of thermal pad treatment.

What output capacitor ESR range ensures stability across all load conditions?

The AP7348D-3330RS4-7 is stable with ceramic capacitors having ESR < 100mΩ. For loads up to 300mA, the datasheet's ESR vs. Output Current graph defines the stable region as ESR ≤ 50mΩ at 300mA. Using higher-ESR capacitors (e.g., tantalum or polymer) risks oscillation during large load transients. Always place 1µF ceramic capacitors within 2mm of each VOUT pin and GND to minimize loop inductance.