LX1662A Datasheet | Microsemi

DESCRIPTION The LX1662/62A and LX1663/63A are Monolithic Switching Regulator Controller IC’s designed to provide a low cost, high performance adjustable power supply for advanced microprocessors and other applications requiring a very fast transient response and a high degree of accuracy. Short-Circuit Current Limiting without Expensive Current Sense Resistors. Current-sensing mechanism can use PCB trace resistance or the parasitic resistance of the main inductor. The LX1662A and LX1663A have reduced current sense parator threshold for optimum performance using a PCB trace. For applications requiring a high degree of accuracy, a conventional sense resistor can be used to sense current. Programmable Synchronous Rectifier Driver for CPU Core. The main output is adjustable from 1.3V to 3.5V using a 5-bit code. The IC can read a VID signal set by a DIP switch on the motherboard, or hardwired into the processor’s package (as in the case of Pentium® Pro and Pentium II processors). The 5-bit code adjusts the output voltage between 1.30 and 2.05V in 50m V increments and between 2.0 and 3.5V in 100m V increments, conforming to the Intel Corporation specification. The device can drive dual MOSFET’s resulting in typical efficiencies of 85 - 90% even with loads in excess of 10 amperes. For cost sensitive applications, the bottom MOSFET can be replaced with a Schottky diode (non-synchronous operation). Smallest Package Size. The LX1662 is available in a narrow body 14-pin surface mount IC package for space sensitive applications. The LX1663 provides the additional functions of Over Voltage Protection (OVP) and Power Good (PWRGD) output drives for applications requiring output voltage monitoring and protection functions. Ultra-Fast Transient Response Reduces System Cost. The modulated offtime architecture results in the fastest transient response for a given inductor, reducing output capacitor requirements, and reducing the total regulator system cost. Over-Voltage Protection and...