The ASRock Fatal1ty X370 Gaming K4 uses a 12-phase CPU voltage regulator circuit for the CPU. The voltage regulator uses an IR35201 controller chip (digital design). Each phase uses one SM4336NSKP (SM4336) and one SM4337NSKP (SM4336) transistors.
This circuit is shown in Figure 9.
Figure 9: voltage regulator circuit
The ASRock Fatal1ty X370 Gaming K4 uses “12K Black” Japanese solid capacitors. All coils on this motherboard are ferrite ones with 45A specification.
If you want to learn more about the voltage regulator circuit, please read our tutorial on the subject.