Linear Regulators (LDO) | CS5257A-1

This new very low dropout regula tor is designed to power the next generation of advanced microprocessors. To achieve very low dropout, the internal pass transistor is powered separately from the control circuitry. Furthermore, with the control and power inputs tied together, this device 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.

It is supplied in five-terminal TO-220 and D² PAK packages, allowing for the implementation of a remote-sense pin permitting very accurate regulation 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 7A.

The very fast transient loop response easily meets the needs of the latest microprocessors. In addition, a small capacitor on the Adjust pin will further improve the transient capabilities.

Internal protection circuitry provides for "bust-proof" operation, similar to three-terminal regulators. This circuitry, which includes overcurrent, short circuit, supply sequencing and overtemperature protection will self protect the regulator under all fault conditions.

The CS5257A-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.