RT9173B pdf datasheet (2A Bus

The RT9173B regulator is designed to convert voltage
supplies ranging from 1.7V to 6V into a desired output
voltage of which adjusted by two external voltage divider
resistors. The regulator is capable of sourcing or sinking
up to 2A of current while regulating an output voltage to
within 40mV.
The RT9173B, used in conjunction with series termination
resistors, provides an excellent voltage source for active
termination schemes of high speed transmission lines as
those seen in high speed memory buses and distributed
backplane designs. The voltage output of the regulator can
be used as a termination voltage for DDR SDRAM.
Current limits in both sourcing and sinking mode, plus onchip
thermal shutdown make the circuit tolerant of the
output fault conditions.
The RT9173B are available in the popular 5-lead TO-252
and fused SOP-8 (the multiple VCNTL pins on the SOP-8
package are internally connected but lowest thermal
resistance) surface mount packages.