C2472 Datasheet, PDF (1/18 Pages) List of Unclassifed Manufacturers – RDFC Controllers for Offline Applications

C2472, C2473 and C2474 Datasheet
RDFC Controllers for Offline Applications
ADVANTAGES
 Low system component count
 High average efficiency
 Low standby power consumption
 EMI compliance without extra components
 High isolation & surge voltage withstand
 High power density in very small size
C2474PW 1
PDIP-8
C2472PX2
SOT23-6
FEATURES
 Highly integrated CMOS controller IC
 Low cost package options
 Drive suitable for low cost bipolar power transistors
 Resonant switching for high efficiency and low EMI
 Frequency optimised for power circuit parasitics
 Protection against overload, over-temperature and under-voltage
C2473PX1
SOP-8
APPLICATIONS
External AC/DC charger/adaptor (single voltage input) e.g. cordless phones, portable electric tools.
Embedded PSU (single voltage input) e.g. set-top boxes, DVD players, audio products, domestic appliances.
OVERVIEW
The C2472, C2473 and C2474 controllers use CamSemi’s Resonant Discontinuous Forward Converter
(RDFC) topology to create a high efficiency, low cost alternative to line-frequency transformer PSUs. By
operating in resonant mode, EMI is greatly reduced, enabling the replacement of linear PSUs in demanding
applications such as audio products and cordless phone chargers. The C2472, C2473 and C2474 controllers
also offer overload protection which is usually associated with more expensive switch mode solutions.
VDD
AUX
Vdd
COL
CS
Switch
saturation
sensing
Resonance
sensing
Current
sensing
Vdd
regulator
RDFC
Control
Base
drive
BAS
GND
Figure 1: Block Diagram of the C2472, C2473 and C2474 Controller ICs
Product data
© Cambridge Semiconductor Ltd 2007
Page 1 of 18
DS-1423-0709C
26-Sep-2007