June 2010
FAN6921ML
Integrated Critical Mode PFC/Quasi-Resonant
Current Mode PWM Controller
Features
Integrated PFC and Flyback Controller
Critical Mode PFC Controller
Zero-Current Detection for PFC Stage
Quasi-Resonant Operation for PWM Stage
Internal Minimum toff 8µs for QR PWM Stage
Internal 10ms Soft-Start for PWM
Brownout Protection
H/L Line Over-Power Compensation (OPC)
Latched Protection (FB Pin)
− Over-Power/ Overload Protection
− Short-Circuit Protection
− Open-Loop Protection
Externally Latch Triggering (RT Pin)
Adjustable Over-Temperature Latched (RT Pin)
VDD Pin & Output Voltage OVP (Latched)
Internal Temperature Shutdown (140°C)
Applications
AC/DC NB Adapters
Open-Frame SMPS
Battery Charger
Description
The highly integrated FAN6921ML combines a Power
Factor Correction (PFC) controller and a Quasi-
Resonant PWM controller. Integration provides cost-
effect design and allows for fewer external components.
For PFC, FAN6921ML uses a controlled on-time
technique to provide a regulated DC output voltage and
to perform natural power factor correction. With an
innovative THD optimizer, FAN6921ML can reduce
input current distortion at zero-crossing duration to
improve THD performance.
For PWM, FAN6921ML enhances the power system
performance through valley detection, green-mode
operation, and high / low line over power compensation.
FAN6921ML provides: secondary-side open-loop and
over-current protection, external latch triggering,
adjustable over-temperature protection by RT pin and
external NTC resistor, internal over-temperature
shutdown, VDD pin OVP, and DET pin over-voltage for
output OVP, and brownin/out for AC input voltage
under-voltage protection (UVP).
The FAN6921ML controller is available in a 16-pin small
outline package (SOP).
Ordering Information
Part Number
OLP Mode
Operating
Temperature Range
Package
FAN6921MLMY
Latch
-40°C to +105°C 16-Pin Small Outline Package (SOP)
Packing
Method
Tape & Reel
© 2010 Fairchild Semiconductor Corporation
FAN6921ML • Rev. 1.0.1
www.fairchildsemi.com