CS5258-1

This new very low dropout regula-tor is designed to power the next generation of advanced microproces-sors. To achieve very low dropout,the internal pass transistor is pow-ered separately from the control cir-cuitry. Furthermore, with the control and power inputs tied together, CS5258-1 can be used in single supply configuration and still offer a better dropout voltage than conventional PNP-NPN based LDO regulators.In this mode the dropout is determined by the minimum control voltage.

CS5258-1 is supplied in a five-terminal TO- 220 package, which allows for the implementation of a remote-sense pin permitting very accurate regula- tion of output voltage directly at the load, where it counts, rather than at the regulator. This remote sensing feature virtually eliminates output voltage variations due to load changes and resistive voltage drops. Typical load regulation measured at the sense pin is 1mV for an output voltage of 2.5V with a load step of 10mA to 8A.

The very fast transient loop response easily meets the needs of the latest microprocessors CS5258-1. In addition, a small capacitor on the Adjust pin will fur- ther improve the transient capabili-ties.

Internal protection circuitry pro-vides for "bust-proof" operation,similar to three-terminal regulators.This circuitry, CS5258-1,which includes over-current, short circuit, supply sequencing and overtemperature protection, will self protect the regu- lator under all fault conditions.

The CS5258-1 is ideal for generating a secondary 2 - 2.5V low voltage supply on a motherboard where both 5V and 3.3V are already available.