LX1672
LX1672 is Multiple Output LoadSHARE PWM manufactured by Microsemi.
TM ®
Multiple Output Load SHARE™ PWM
P RELIMINARY D ATA S HEET
DESCRIPTION
KEY Features
. Microsemi . C OM
The LX1672 is a highly integrated power supply controller IC featuring ..net two PWM switching regulator stages with an additional onboard linear regulator driver. The two constant frequency voltagemode PWM phases can be easily configured as a single Bi-Phase high current output, two independently regulated outputs, or as a DDR memory I/O supply with a tracking DDR termination voltage supply. Power loss and noise, due to the ESR of the input capacitors, are minimized by operating each PWM output 180° out of phase. This architecture also minimizes capacitor requirements while maximizing regulator response. In bi-phase operation, the high current output utilizes a patented current sharing architecture, called Forced Current Sharing†, to allow accurate current sharing without the use of expensive current sense resistors.
This patented approach also gives system designers maximum flexibility with respect to MOSFET supply. Each phase can utilize different supply voltages, for efficient use of available supplies, while programming the ratio of current pulled from each using one of three methods (see application section). The LX1672 incorporates fully programmable soft-start sequencing capabilities. Each output can be configured to e up in any order necessary as required by the application. The LX1672 Features an additional Linear Regulator Driver output, which when coupled with an inexpensive MOSFET is capable of supplying up to 5A for I/O, memory, and other supplies surrounding today’s micro-processor designs. Each regulator voltage output is programmed via a simple voltage-divider network. The LX1672, utilizing MOSFET RDS(ON) impedance, monitors maximum current limit conditions, in each PWM phase without the use of expensive current sense resistors.
- Up to Three Independently Regulated Outputs
- DDR Termination pliant
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