Diodes Incorporated APR348W6-7

Overview

APR348W6-7 from Diodes Incorporated is a secondary-side synchronous rectification controller IC for flyback converters, supporting CCM, DCM, and quasi-resonant operation with minimized turn-on/turn-off delay (30–60 ns / 25–45 ns), VDD regulation (5.0–6.5 V), and wide output voltage range (3.3–20 V). It operates in high-side or low-side configurations and features light-load mode for burst-mode efficiency in AC/DC adapters.

For engineers reviewing the APR348W6-7 datasheet, APR348W6-7 pinout, APR348W6-7 application, or APR348W6-7 equivalent, this device is selected for high-efficiency secondary-side gate driving where precise VDET-sensed MOSFET timing, internal UVLO (3.30–3.70 V), and minimal external components are critical in compact charger designs.

Technical Context

The APR348W6-7 implements drain-voltage sensing via VDET to trigger synchronous rectification MOSFET gate drive (DRISR) with adaptive blanking-minimum on-time (0.8–1.6 µs) suppresses false turn-on during resonant ringing. Its dual-regulator architecture supplies VDD from either VCC (LDO) or VDET (PLR), enabling bias across 3.3–20 V output rails.

It integrates load-detection logic for light-load mode: skipping 2 cycles for 640 µs–2.5 ms intervals, and 8 cycles beyond 2.5 ms. The Rx resistor (30–40 kΩ) sets accurate turn-on threshold via internal current source, while VTHOFF (−7 to 0 mV) and VFWD (−55 to −35 mV) define forward regulation and turn-off behavior.

Key Specifications

Pinout & Package

SOT26 (Type CJ) package: 6-pin, surface-mount, matte tin-plated leads, MSL Level 1, 0.016 g weight, thermal resistance θ_JA = 197 °C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous rectification controller applications.

Compared with MP6908A and SRK1001, the APR348W6-7 uniquely combines dual-path VDD regulation, 150 V VDET tolerance, high/low-side flexibility, and programmable light-load mode-enabling single-design reuse across 5–20 V USB PD, QC, and industrial adapters without layout or BOM changes.

Availability

APR348W6-7 is available at Aetrix Electronics and suitable for USB PD adapters, quick-charge wall chargers, and industrial PoE PSE adapters requiring stable component supply, full RoHS compliance, and MSL Level 1 handling.

Supply support for APR348W6-7 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 connectivity solutions for consumer, industrial, and automotive markets.

The APR348 belongs to Diodes' secondary-side SR controller product line, designed specifically to replace Schottky diodes in flyback converters-maximizing efficiency, minimizing thermal footprint, and simplifying high-density adapter design.

FAQ

What is the maximum VDET voltage rating and why does it matter?

The APR348W6-7 supports up to 150 V at the VDET pin, enabling direct connection to high-voltage secondary windings in 20 V+ USB PD and industrial flyback designs. This eliminates the need for external voltage dividers or clamping circuits, preserving timing accuracy and reducing component count-critical for maintaining <60 ns turn-on delay under high dv/dt conditions.

How does the light-load mode reduce standby power?

The APR348W6-7 implements two-tier burst-mode skipping: 2 cycles skipped for 640 µs–2.5 ms intervals, and 8 cycles beyond 2.5 ms. This dynamically scales gate drive activity with load, cutting quiescent current to <220 µA while maintaining regulation-achieving <30 mW no-load consumption without external control signals or firmware.

Can APR348W6-7 be used in high-side and low-side configurations simultaneously?

No-the APR348W6-7 must be configured for either high-side or low-side operation per design, determined by VDD sourcing path (VDET-only for high-side; VCC+VDET for low-side). However, the same part number supports both topologies via PCB layout and bias routing-no different variants or firmware changes are required.

What is the role of the Rx resistor and what value should be used?

Rx (pin 3) sets the turn-on threshold via an internal current source. A 30–40 kΩ resistor yields optimal VTHON (−130 to −60 mV) for reliable zero-voltage switching across temperature and process variation. Values outside this range risk premature turn-on or delayed activation, increasing conduction loss or causing false triggering during ringing.