US3034

US3034 8 PIN PWM SWITCHER CONTROLLER IC FEATURES 8 pin SOIC Switching Controller with HICCUP Current Limiting Reduces Diode Power Dissipation to Less than 1% of Normal Operation Soft Start Capacitor allows for smooth Output Voltage ramp up On board MOSFET driver Fastest transient response of any controller method. ( 0 to 100% Duty Cycle in 100 nS ) 1% internal voltage reference Internal Under Voltage Lockout protects MOSFET during start-up PRELIMINARY DATASHEET DESCRIPTION The US3034 IC provides an 8 pin low cost switching controller with true short circuit protection all in a compact 8 pin surface mount package, providing a low cost switching solution for dual supply processor applications that require switching regulator for the 3.3V supply such as the applications with AGP on board. Typically in these applications a dual supply regulator converts 5V to 3.3V for I/O supply and a jumper programmable supply of 1.25V to 3.5V for CORE supply . The IC uses an internal regulator generated from the 12V supply to power the controller as well as the 12V supply to drive the power MOSFET, allowing a low cost N channel MOSFET to be used. The IC also includes an error comparator for fast transient response, a precise voltage reference for setting the output voltage as well as a direct drive of the MOSFET for the minimum part count. APPLICATIONS Dual supply low voltage processor applications, such as: P55C™,CYRIX M2™, POWER PC™ and AMD K6™ Simple 5V to 3.3V switcher for Pentium with AG...