The RT8800A is a general-purposed multi-phase
synchronous buck controller dedicating for high power
density applications. The RT8800A operates with 2 or 3
synchronous buck switching stages 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.
The output voltage is precisely regulated to the external
reference voltage at PI pin. The RT8800A can provide Intel?
VRD10.x or AMD? K8 compliant output voltage when
companioned with DAC generator RT9401A/B.
The RT8800A adopts innovative time-sharing DCR current
sensing technique for channel current balance, droop
tuning, and over current protection. Using one common
GM amplifier for current sensing eliminates offset errors
and linearity variation between GMs. As sub-milli-ohmgrade
inductors are widely used in modern mother boards,
slight mismatch of GM amplifiers offset and linearity results
in considerable current shift between phases. The timesharing
DCR current sensing technique is extremely
important to guarantee phase current balance at mass
production.
Other features include overvoltage protection, undervoltage
protection and internal softstart. The RT8800A comes to
a VQFN-16L 3x3 package.