Diodes Incorporated AP3303S9-13

Overview

AP3303S9-13 from Diodes Incorporated is a peak-current-mode, quasi-resonant (QR) PWM controller for offline flyback AC-DC power supplies. It delivers ultra-low standby power (<50 mW), operates across universal AC input (85–265 VAC), supports 24 kHz minimum / 120 kHz maximum switching frequency with frequency foldback, and integrates HV startup, VCC LDO, and comprehensive protection including SOVP/SUVP, FOCP, OLP, and OTP. It enables USB PD/quick-charge compatible adapter designs.

For engineers reviewing the AP3303S9-13 datasheet, AP3303S9-13 pinout, AP3303S9-13 application, or AP3303S9-13 equivalent, key selection criteria include QR valley detection timing (50 mV threshold), adaptive burst mode entry (VBURST = 0.66–0.933 V), line-compensated constant OCP, integrated HV startup current (0.23–2 mA), and SSOP-9 (Type CJ) package compatibility with thermal resistance of 177 °C/W.

Technical Context

The AP3303S9-13 implements valley-synchronized QR control via DEM pin sensing (50 mV threshold) with 2 µs sample delay and blanking to reject leakage-induced false triggers. Its frequency modulation responds to FB voltage: first-valley operation at full load, multi-valley shifting under green mode, and burst mode activation below VBURST.

It combines internal piecewise linear line compensation (via HV pin current IDEM) to maintain constant output power limit across 85–265 VAC input, and integrates a wide-input VCC LDO (10–40 V VCC_IN → regulated 9–16 V VCC) with 6–11 mA operating current - enabling stable operation in variable-output-voltage adapters.

Key Specifications

Pinout & Package

AP3303S9-13 is housed in a lead-free, RoHS-compliant SSOP-9 (Type CJ) package with exposed pad for thermal enhancement. Pin layout is optimized for compact flyback transformer feedback and gate drive routing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quasi-resonant PWM controller applications.

Compared with NCP1342DR2G and ICE2QS03G, the AP3303S9-13 uniquely integrates HV startup, VCC LDO, DEM-based protection, and adaptive burst mode - enabling single-chip compliance with stringent global efficiency standards without auxiliary components.

Availability

AP3303S9-13 is available at Aetrix Electronics and suitable for USB-C PD adapters, ATX auxiliary power rails, and set-top box power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for AP3303S9-13 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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal ICs for power management, signal integrity, and connectivity applications.

The AP3303 belongs to Diodes' high-efficiency AC-DC controller product line, designed specifically for ultra-low-standby, QR-based flyback converters targeting USB PD, consumer, and industrial adapter markets.

FAQ

What is the purpose of the DEM pin on the AP3303S9-13?

The DEM pin detects transformer demagnetization zero-crossing to enable valley-switching QR operation. It also serves dual protection functions: SOVP (startup threshold 1.0–1.2 V, steady-state 2.5–2.7 V) and SUVP (0.475 V threshold with 20 ms blank time after startup). Its 50 mV valley detection threshold and 2 µs sample delay ensure reliable timing while rejecting noise from leakage inductance ringing.

How does the AP3303S9-13 achieve ultra-low standby power?

It combines three mechanisms: (1) HV pin startup with low-current charging (0.23 mA) before VCC reaches 15.8 V, (2) adaptive burst mode triggered by FB voltage falling below VBURST (0.66–0.933 V depending on DEM level), and (3) VCC maintain mode holding 7.3 V during faults to minimize quiescent draw. These features collectively enable <50 mW no-load consumption in certified USB PD adapters.

Can the AP3303S9-13 be used with synchronous rectification controllers?

Yes - it is explicitly designed to coordinate with Diodes' APR347 synchronous rectifier controller. The AP3303's DEM pin provides accurate valley timing signals, while its GATE driver (350 mA, 150 ns rise time) supports fast turn-on of primary MOSFETs in high-frequency QR systems. This pairing achieves >94% efficiency at 24 W and improves thermal performance versus diode rectification.

What is the function of the CTRL pin, and how is it protected?

The CTRL pin accepts external fault signals (e.g., from OTP thermistor or overtemperature latch) with programmable thresholds: low-level trigger at 0.97–1.03 V and high-level at 2.9–3.1 V. It includes internal clamping (4.5 V max) and 20 ms blanking after low assertion to prevent false triggering. Current sourcing is limited to –90 to –110 µA, and exceeding 5 mA sink current risks permanent damage per datasheet Note 11.