EZ1900

REGULATOR BALANCE CONTROLLER May 27, 1999 EZ1900 TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com DESCRIPTION The EZ1900 is a high performance positive load current balancer designed for use in applications utilizing 2 regulators in parallel to achieve equal current sharing or identical current for each load. The regulator balance controller allows a flexible motherboard design to be made to cope with different processor configurations. The controller reads a logic level upgrade signal (denoted VCC2DET on the Intel P55C; similar on AMD, Cyrix and PowerPC microprocessors) to control the output voltage of two linear low dropout voltage regulators to the CPU core and I/O planes. In single-voltage plane configurations (VCC2DET floating), both regulators are set to the same output voltage (usually 3.3 - 3.5V) and are configured in masterslave mode. For split plane processors (VCC2DET low), the outputs of the two regulators are switched - the core voltage will be set to a nominal 2.5V while the I/O voltage will remain at 3.3V. The actual output voltages can be adjusted by means of resistors. The EZ1900 programmable current balancer is available in the popular SO-8 surface mount package. FEATURES Current balance controller for regulators in parallel Slave and non-slave voltage modes Slave or non-slave mode computer selected Compatible with 3 or 5 pin low drop regulators Remote sense operation SO-8 package APPLICATIONS Flexible upgrade from single...