The RT8801B is a multi-phase synchronous buck controller
which is implemented with full control functions for AMD
K8 compliant CPU. The RT8801B could be operated with
2, 3 or 4 buck switching stages operating in interleaved
phase set automatically. The multiphase architecture
provides high output current while maintaining low power
dissipation on power devices and low stress on input and
output capacitors.
RT8801B is one of RichTek CPU core power solutions
which integrates a specific series programming interface
for the controller peration configuration. There are several
registers implemented for the specific parameters
configuration including VID for core power, and signal for
load current indication. User can program the configuration
of the parameters easily via the specific programming
interface. With the implementation of RT8801B, the part
provides more flexibility and feature for customers advanced
segment product design.
The RT8801B applies the DCR sensing technology newly
as well; with such a topology, the RT8801B extracts the
DCR of output inductor as sense component to deliver a
more precise load line regulation and better thermal
balance for next generation processor application. For
current sense setting, droop tuning, VCORE initial offset
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 DAC output of RT8801B supports AMD CPU
with 6-bit VID input, precise initial value & smooth VCORE
transient at VID jump. The IC monitors the VCORE voltage
for 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. The RT8801B comes to the package of
VQFN-32L 5x5.