SC4911 Datasheet | SEMTECH

Description The SC4911 is a highly integrated bias/primary side PWM controller designed for off-line or isolated dc-dc converters in telemunication and data munication applications. The high degree of integration minimizes the amount of discrete parts needed and leads to substantial cost and space saving converter designs. The circuitry of the SC4911 includes line voltage UVLO featuring startup current less than 50µA and program.. mable switching frequency. The device supply is derived from an auxiliary winding on the transformer. The auxiliary winding could also provide output feedback information if an optocoupler is not used. Features ‹ ‹ ‹ ‹ ‹ ‹ Programmable switching frequency up to 500k Hz Line UVLO Protection Undervoltage Lockout Low startup current (45µA) Cycle by cycle current limit 8 pin MSOP. Available in Lead-free, fully WEEE and Ro HS pliant Applications ‹ ‹ ‹ ‹ Tele isolated converters Offline isolated power supplies Instrumentation power supplies Battery chargers Typical Application Circuit D1 C1 C2 C3 R2 R3 R4 C4 C6 U1 SC4911 Q1 1 8 T1 D2 R1 Vin Vout C5 R5 LUVLO 4 R7 C7 P GND RT ILIM R6 C8 R8 R9 Revision: April 5, 2006 .semtech. POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Supply Voltage Supply Current Line UVLO Voltage FB, ILIM and P .. Symbol V CC ICC Maximum 18 20 VCC -0.3 to 6 250 Units V m A V V m A °C °C °C k V Output Current Source or Sink TSTG TJ TLEAD ESD Storage Temperature Range Junction Temperature Range Lead Temperature (Soldering) 10 Sec. ESD Rating (Human Body...