Diodes Incorporated AP7368D-09RS4-7

Overview

AP7368D-09RS4-7 from Diodes Incorporated is a 500mA/1A low-noise RF LDO regulator in X1-DFN1612-8 (Type B) package, delivering fixed 0.9V output with ±1% accuracy, 80dB PSRR at 1kHz, and 16µV_rms output noise (10Hz–100kHz). It features dual current-limit selection (via LCON pin), 110µA quiescent current, and is optimized for RF supply rails in portable wireless devices.

For engineers reviewing the AP7368D-09RS4-7 datasheet, AP7368D-09RS4-7 pinout, AP7368D-09RS4-7 application, or AP7368D-09RS4-7 equivalent, key selection criteria include low-noise performance for sensitive RF stages, thermal behavior in ultra-compact layouts, enable-controlled power sequencing, and LCON-configurable current limit for system-level fault containment.

Technical Context

The AP7368D-09RS4-7 integrates a CMOS-based error amplifier, precision voltage reference, foldback short-circuit protection, and auto-discharge NMOS (30Ω on-resistance) for controlled shutdown. Its architecture supports stable operation with 1µF ceramic input/output capacitors and achieves <2% output deviation across –40°C to +85°C ambient.

It implements dual-mode current limiting: 500mA when LCON = low (with 300mA inrush limit), and 1A when LCON = high (with 500mA inrush limit); short-circuit foldback drops to 60mA (LCON = low) or 110mA (LCON = high), enabling robust transient fault handling without thermal runaway.

Key Specifications

Pinout & Package

X1-DFN1612-8 (Type B) package: 1.6mm × 1.2mm footprint, 0.4mm pitch, exposed thermal pad (EP) for enhanced heat dissipation; JEDEC MS-012 compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise RF LDO applications.

Compared with XC6216D092MR-G and RT9080AL-09GJ5, the AP7368D-09RS4-7 uniquely combines 16µV_rms noise, dual current-limit selection, and auto-discharge in a 1.6mm×1.2mm DFN-making it optimal for space-constrained, battery-powered RF systems requiring both precision and fault resilience.

Availability

AP7368D-09RS4-7 is available at Aetrix Electronics and suitable for RF power amplifier biasing, low-voltage microcontroller core supplies, and wireless camera sensor interfaces requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7368D-09RS4-7 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 AP7368 belongs to Diodes' RF-optimized LDO family, designed specifically for noise-sensitive wireless infrastructure and portable communication equipment where PSRR, output noise, and thermal efficiency in miniature packages are critical.

FAQ

What is the recommended PCB layout for thermal management of AP7368D-09RS4-7?

The X1-DFN1612-8 (Type B) package requires the exposed pad (EP) to be soldered to a minimum 20mm² copper area connected to GND. Use 4–6 thermal vias (0.3mm diameter, spaced ≤1mm apart) beneath the EP to transfer heat to inner ground planes. Keep VIN/VOUT traces wide (>0.5mm) and place 1µF ceramic CIN/COUT within 2mm of respective pins to minimize loop inductance and ensure stability.

How does the LCON pin affect short-circuit protection behavior?

When LCON = low, short-circuit foldback limits output current to 60mA; when LCON = high, it limits to 110mA. This scaling ensures proportional fault containment: lower LCON setting provides tighter current clamping for low-power peripherals, while higher setting maintains functionality for 1A loads during brief overload events without triggering thermal shutdown.

Can AP7368D-09RS4-7 operate with input voltage below 1.7V?

No. The absolute minimum input voltage is 1.7V per datasheet specifications. At 0.9V output, dropout voltage is 0.095V (typical) at 500mA, meaning VIN must be ≥ 0.995V - but functional operation requires VIN ≥ 1.7V to guarantee all electrical characteristics including PSRR, noise, and regulation accuracy across temperature and process variation.

Is the VFB pin accessible for external adjustment in AP7368D-09RS4-7?

No. The AP7368D-09RS4-7 is a fixed-output variant; VFB is internally connected to the resistor divider network set for 0.9V. Only adjustable versions (e.g., AP7368W-xx) expose VFB for external feedback. Attempting to drive or load VFB on this part may disrupt regulation or cause instability.