CURRENT MODE PWM CONTROLLER
DESCRIPTION
SD4870 is a current mode PWM controller IC for high performance,
low standby power offline flyback converter application.
In no load or light load condition, the IC operates in Light Load
Mode to reduce switching loss and improve efficiency.
Large value startup resistor could be used in the startup circuit to
minimize the standby current because of low startup current.
SD4870 offers complete protection functions including cycle-by-
cycle over current protection, over load protection, V
DD
input
voltage over voltage and under voltage protection, etc.
Excellent EMI performance is achieved with frequency shuffling
technique and soft switching control at the totem pole gate driver
output.
DIP-8-300-2.54
SOP-8-225-1.27
SOT-23-6L
FEATURES
* Frequency shuffling to improve EMI performance
* Light Load Mode for minimum standby power
* External programmable switching frequency
* 3uA low startup current
* Internal LEB circuit
* VDD over voltage and under voltage protection
* Gate output maximum voltage clamp
* Over current protection
* Over load protection
* SOT-23-6L/SOP8/DIP8 package
APPLICATIONS
* Battery Chargers
* Adapters
* Set-Top Box Power Supplies
ORDERING INFORMATION
Part No.
SD4870TR
SD4870A
SD4870C
SD4870CTR
Package
SOT-23-6L
DIP-8-300-2.54
SOP-8-225-1.27
SOP-8-225-1.27
4870
SD4870A
SD4870C
SD4870C
Marking
Material
Pb free
Pb free
Pb free
Pb free
Packing Type
Tape & Reel
Tube
Tube
Tape & Reel
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http://www.silan.com.cn
REV:1.0
2009.09.22
Page 1 of 8
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