SC4812
SC4812 is Current Mode PWM Controller manufactured by SEMTECH.
Current Mode PWM Controller with Integrated Start-up Circuit and Op Amp
POWER MANAGEMENT Description
The SC4812 is a highly integrated current mode PWM controller designed for isolated or non-isolated dc-dc converters in telemunication and data munication applications. It minimizes the amount of external discrete ponents needed and leads to substantial cost and space saving converter designs.
Features
Wide input range 12V to 90V High-voltage start-up circuit Current mode control Transconductance error amplifier Leading-edge blanking Cycle by cycle current limit Programmable external soft-start Thermal shutdown SO-8 package. Fully WEEE and Ro HS pliant
The circuitry of the SC4812 includes an integrated high voltage start-up circuit suitable for tele/industrial .. voltage applications. It is disabled during regular opera- tion and improves efficiency. Current mode control with leading-edge blanking simplifies control loop design and internal ramp pensation circuit stabilizes the current loop when operating above 50% duty cycle. Internal error amplifier could be used for non-isolated applications.
Applications
IP phones, Po E Tele isolated converters Off-line isolated power supplies Instrumentation power supplies Battery chargers
Typical Application Circuit
Vin
T1 C2 C3 R2 1 U1
D1 C1
Vout
R1
C4
Q1 7 5 6 R5
2 3 C5 R3 R4 4 C6
FB SC4812 P SS/SHDN
OUT CS GND
Revision: February 6, 2007
.semtech.
POWER MANAGEMENT Pin Configuration
TOP VIEW
Ordering Information
Part Number SC4812STRT(1)(2) Top Mark S C 4812 P ackag e SO-8
VIN FB P
..
VCC OUT GND...
