Diodes Incorporated AP39811BS7-13

Overview

AP39811BS7-13 from Diodes Incorporated is a primary-side regulated (PSR) flyback power switcher integrating a 650V N-channel MOSFET and controller for shaver charger applications. It delivers slant IV curve control without opto-coupler or secondary feedback, achieves ≤75mW no-load input power, operates in DCM with PFM/AM hybrid modulation, and provides valley-on switching for improved efficiency and EMI performance.

For engineers reviewing the AP39811BS7-13 datasheet, AP39811BS7-13 pinout, AP39811BS7-13 application, or AP39811BS7-13 equivalent, key selection criteria include slant IV curve programmability via FB–CPR resistor, integrated transformer saturation protection, VCS_H/VCS_L dual current-sense thresholds (600mV/200mV typ), and SO-7 package thermal resistance (θJA = 78°C/W).

Technical Context

The AP39811BS7-13 implements primary-side regulation using auxiliary winding voltage sampling during tONS to derive output voltage, with CV control maintaining VFB = 2.35V (typ) and SV mode enabled by CPR pin voltage modulation. Its enhanced cable compensation logic uses internal VCPC proportional to load current and fixed VCPR_CABLE_MIN (2.14V for 'B' variant) to define the CV-to-SV inflection point.

It combines three-segment peak current control (VCS_L = 200mV, VCS_H = 600mV, VCS_M interpolated) to sustain switching frequency >20kHz across load range, plus valley-on turn-on (tVAL-ON = 32μs typ) and active VCS jitter (±3% modulation) to suppress audible noise and improve conducted/radiated EMI.

Key Specifications

Pinout & Package

AP39811BS7-13 is housed in a surface-mount SO-7 package with exposed drain pads (pins 5 & 6) for thermal dissipation and integrated MOSFET source sensing (pin 4). The 7-pin layout supports compact shaver charger PCB designs with minimal external components.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar primary-side regulated flyback switcher applications.

Compared with MP6908GJ-Z and LNK3206P, AP39811BS7-13 uniquely integrates slant IV generation, eliminating both opto-coupler and secondary controller while delivering certified touch-current compliance-making it the only drop-in solution for IEC 62368-1 shaver charger designs.

Availability

AP39811BS7-13 is available at Aetrix Electronics and suitable for shaver charger production, personal care device adapter development, and compact medical skin therapy device power supply design requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for AP39811BS7-13 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.

The AP39811 belongs to Diodes' PSR Switcher product line, engineered specifically for low-power, space-constrained AC/DC adapters requiring slant IV compliance, no-opto operation, and ultra-low standby consumption.

FAQ

What is the function of the CPR pin in AP39811BS7-13?

The CPR pin enables slant IV curve control by accepting a resistor-connected voltage from the FB pin. Its internal circuitry generates a load-proportional compensation voltage (VCPR) that decreases output voltage linearly beyond the CV–SV inflection point. For AP39811B, VCPR_CABLE_MIN is fixed at 2.14V, defining the SV onset threshold relative to full CC current.

How does AP39811BS7-13 achieve audible-noise-free operation?

It uses three-segment peak current control (VCS_L/VCS_M/VCS_H) to maintain switching frequency above 20kHz across 3–100% load, combined with valley-on turn-on (32μs typical tVAL-ON) and active VCS jitter (±3% modulation). These features eliminate transformer whine and reduce EMI peaks without requiring external frequency dithering circuits.

Can AP39811BS7-13 be used in non-shaver applications?

Yes-it supports any low-power (<10W) flyback application requiring PSR, slant IV, or ultra-low no-load power. Valid use cases include USB-C accessories, compact medical devices, and personal care adapters where CV→SV→CC transition meets safety standards like IEC 62368-1. Designers must verify transformer turns ratio and FB/CPR resistor values for target output profiles.

What thermal considerations apply to the SO-7 package?

The SO-7 package has θJA = 78°C/W and θJC = 2°C/W. To maintain T_J ≤125°C at full load, PCB layout must provide ≥1 inch² copper pour under pins 5/6 (DRAIN) with 2oz copper, and ensure VCC decoupling capacitor is placed within 5mm of pin 3. Thermal relief on SOURCE (pin 4) should be minimized to preserve current-sense accuracy.