ASRock 990FX Extreme9 Motherboard

Voltage Regulator

The CPU voltage regulator circuit of the ASRock 990FX Extreme9 has 12 phases for the CPU main voltage (VDD a.k.a. Vcore) and two for the CPU VDDNB (integrated memory controller, HyperTransport interface controller, and L3 memory cache) voltage. Therefore, it uses a “12+2” configuration.

The voltage regulator is controlled by a CHIL8328 integrated circuit using a digital design, which is superior to the analog (a.k.a. “hybrid”) design usually seen on motherboards from ASRock.

Each phase is driven by a CSD87350Q5D integrated circuit, which incorporates the “high side” and “low side” transistors, providing higher efficiency than discrete solutions. 

Figure 8: Voltage regulator circuit

The ASRock 990FX Extreme9 uses solid electrolytic capacitors, and three SMD (a.k.a. highly-conductive polymerized or simply Hi-c) capacitors are also used. All coils on this motherboard are ferrite-core models, which can provide up to 20% improvement in efficiency.

If you want to learn more about the voltage regulator circuit, please read our tutorial on the subject.