Biostar uses Intersil parts on their B550 boards. Both have the same Dr.MOS design with doublers used for SoC side.
B550GTA 10-phase[6+4] | ISL99360?, PWM: ISL229004
B550GTQ 10-phase[6+4] | ISL99360?, PWM: ISL229004
You find the parts on the product page photos, though a little hard to read but with a little effort you figure it out.
I figured it was the ISL993?