AP31261 Datasheet, PDF (1/13 Pages) Diodes Incorporated – GREEN MODE PWM CONTROLLER

Description
A Product Line of
Diodes Incorporated
AP31261
GREEN MODE PWM CONTROLLER
Pin Assignments
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-by-
cycle current limit (OCP), VCC Over Voltage Protection (VOVP),
internal OTP, Over Load Protection (OLP) and pins’ fault protection.
Features
(Top View)
Pin 1 Mark
GND ₁
FB
2
CTRL 3
6 GATE
5 ^VCC
4 ^SENSE
SOT26
 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 (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3)
Applications
 Switching AC-DC Adapter/Charger
 ATX/BTX Auxiliary Power
 Set-top Box (STB) Power Supply
 Open Frame Switching Power Supply
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
AP31261
Document number: DS37514 Rev. 2 - 2
1 of 13
www.diodes.com
May 2015
© Diodes Incorporated