Diodes Incorporated AP3917CS7-13

Overview

AP3917CS7-13 from Diodes Incorporated is a universal AC-input step-down power switcher integrating a 650V MOSFET, designed for non-isolated buck and offline flyback topologies in home appliances and IoT devices. It delivers up to 270mA rated output current, achieves <30mW no-load power consumption with external bias, maintains ±5% constant voltage regulation, and operates across 85–300VAC input range.

For engineers reviewing the AP3917CS7-13 datasheet, AP3917CS7-13 pinout, AP3917CS7-13 application, or AP3917CS7-13 equivalent, key selection criteria include its integrated 650V MOSFET, adaptive frequency modulation for light-load efficiency, multi-protection architecture (OTP/OLP/SCP/open-loop), SO-7 thermal performance (θJA = 95°C/W), and low-BOM implementation with single-winding inductor.

Technical Context

The AP3917CS7-13 implements a self-supplied, current-mode PWM controller with internal 650V high-voltage MOSFET and adaptive peak-current limiting. Its VBP supply uses hysteresis-based HV startup (VBP_HVON = 8.2V, VBP_HVOFF = 8.5V) and latch-off restart at 4.5V, enabling robust fault recovery. The FB pin senses output via resistive divider and triggers switching when voltage drops below 2.5V reference.

It employs dynamic frequency scaling-switching frequency and peak current both decrease under light load-to suppress audible noise and improve efficiency down to <30mW no-load. Protection logic includes time-delayed OLP (170ms at 36kHz), SCP with dual leading-edge blanking (tLEB1 = 250–400ns, tLEB2 = 200ns), and OTP shutdown at +150°C junction temperature.

Key Specifications

Pinout & Package

AP3917CS7-13 is housed in a thermally enhanced SO-7 package (4.9mm × 6.0mm × 1.45mm), featuring matte tin-plated leads (MSL Level 3), 0.077g mass, and optimized pad layout per Diodes' SO-7 outline (E1 = 3.85mm, e = 1.27mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar universal AC-input step-down power switcher applications.

Compared with AP3917CS7-13, AP3915CS7-13 trades universal input and advanced light-load optimization for lower cost, while LNK3206D adds isolation and safety features at the expense of component count and design simplicity-making AP3917CS7-13 optimal for cost-constrained, non-isolated, ultra-low-standby applications.

Availability

AP3917CS7-13 is available at Aetrix Electronics and suitable for non-isolated home appliance power supplies, IoT edge device auxiliary rails, and industrial control panel standby circuits requiring stable component supply and long-term manufacturability.

Supply support for AP3917CS7-13 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 industrial, computing, and consumer markets.

The AP3917C belongs to Diodes' AC-DC primary-side switcher product line, engineered specifically for cost-sensitive, non-isolated buck and flyback converters in home appliances and smart IoT endpoints where minimal BOM count and ultra-low standby power are critical.

FAQ

What is the minimum external BP capacitor value required for stable operation?

The AP3917CS7-13 requires a minimum 10µF/16V electrolytic or tantalum capacitor on the BP pin. This value ensures sufficient energy storage for startup and fault recovery, supports the 170ms OLP timer, and maintains stable VBP regulation during load transients. Smaller values may cause erratic restart behavior or premature shutdown under dynamic loads.

Can AP3917CS7-13 operate in continuous conduction mode (CCM)?

Yes-AP3917CS7-13 supports both discontinuous (DCM) and continuous conduction modes. CCM operation occurs at higher output currents (>150mA) and is governed by the equation f_s = V_O(V_IN−V_O)/(2L(V_IN−V_O)), where inductance and load determine boundary conditions. The IC automatically transitions between modes without external configuration.

How does the open-loop protection function during startup?

Open-loop protection is blanked for the first 64 switching cycles after power-up to prevent false triggering during soft-start. After this period, if FB voltage falls below 60mV-indicating loss of feedback path or output short-the IC stops switching and initiates a restart cycle by discharging the BP capacitor to 4.5V before attempting recovery.

Is AP3917CS7-13 qualified for automotive applications?

No-AP3917CS7-13 is not AEC-Q100 qualified. Diodes Incorporated explicitly states that automotive use requires parts qualified to AEC-Q100/101/200 with PPAP capability and IATF 16949 manufacturing. This device targets industrial, consumer, and IoT applications where extended temperature range (−40°C to +125°C) suffices but automotive-grade reliability is not mandated.