描述 Description

The AP31261 is a current mode PWM controller which is optimized
for high performance, low standby power and cost effective offline
flyback converters.
The PWM switching frequency at normal operation is internally fixed
(about 65kHz). In middle load, the IC will enter green mode to
improve system efficiency with the help of frequency foldback. A
minimum switching frequency (about 20kHz) is set to avoid the
audible noise. In no load or light load, the IC will enter the burst mode
to minimize standby power. Furthermore, the frequency dithering
function is built-in to reduce EMI emission. Internal slope compensation allows more stable Peak-Current Mode
control over wide range of input voltage and load conditions. Internal line compensation ensures constant output power limit over entire universal line voltage range. Comprehensive protection features are included, such as cycle-bycycle current limit (OCP), VCC Over Voltage Protection (VOVP), internal OTP, Over Load Protection (OLP) and pins’ fault protection.

特性 Features

Very Low Start-up Current
Current Mode Control
Non-audible-noise Green-mode Control
Internal Slope Compensation
Soft Start During Startup Process
Frequency Fold Back for High Average Efficiency
Secondary Winding Short Protection with FOCP
Soft Switching for Reducing EMI
VCC Maintain Mode
Useful Pin Fault Protection:
?????SENSE Pin Floating
?????CTRL Pin Short to Ground
?????FB/Opto-coupler Open/Short
Comprehensive System Protection Feature:
?????VCC Over Voltage Protection (VOVP)
?????Over Load Protection (OLP)
Mini Size Package of SOT26
Pin to Pin Compatible with AP3125A/V/R/L
Totally Lead-free & Fully RoHS Compliant
Halogen and Antimony Free. “Green” Device

應(yīng)用 Application

Switching AC-DC Adapter/Charger
ATX/BTX Auxiliary Power
Set-top Box (STB) Power Supply
Open Frame Switching Power Supply