The RT9241 is a two-phase buck DC/DC controller
integrated with all control functions for high
performance processor VRM. The RT9241 drives 2
buck switching stages operating in 180 degree
phase shift. The two-phase architecture provides
high output current while maintaining low power
dissipation on power devices and low stress on
input and output capacitors. The high equivalent
operating frequency also reduces the component
dimension and the output voltage ripple in load
transient.
RT9241 regulates both easily set voltage and
current loops. Precise current sharing for power
stage is achieved by differential input current sense
and processing circuit. The settings of current
sense, droop tuning and over current protection are
independent to compensation circuit of voltage loop.
The feature greatly facilitates the flexibility of CPU
power supply design and tuning.
The RT9241 uses a 5-bit DAC of 1.1V to 1.85V
(25mV/step) output with load current droop
compensation to meet the strict VRM transient
requirement. The IC monitors the VCORE voltage
for PGOOD and over voltage protection. Soft start,
over current protection and programmable under
voltage lockout are also provided to assure the
safety of microprocessor and power system.