Intel DZ77GA-70K Motherboard
Voltage Regulator
Contents
The CPU voltage regulator circuit of the Intel DZ77GA-70K has eight phases for the CPU main voltage (Vcc a.k.a. Vcore), two for the CPU VSA voltage (memory controller), one for the CPU VTT voltage (PCI Express and DMI interfaces), and one for the CPU integrated video controller (VAXG). Therefore, it uses an “8+2+1+1” configuration.
Figure 9: Voltage regulator circuit
The voltage regulator is controlled by a CHiL CHL8328 integrated circuit, using a digital design, and each phase is controlled by an FDMF6707B integrated circuit, which combines the three required transistors (“high side,” “low side,” and “driver”) and are able to use a switching frequency of up to 1 MHz, allowing efficiency above 90 percent. (Usually, motherboard voltage regulator circuits switch at 250 kHz.) Integrated circuits with these characteristics are known as “DrMOS.”
The Intel DZ77GA-70K uses solid electrolytic capacitors. 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.
The portrayed motherboard comes with a series of LEDs near the EPS12V connector for you to monitor the active phases.
Figure 10: Phase-monitoring LEDs