Patent ID: 7543162

Claim:
A CPU frequency regulating circuit comprising: a detecting circuit coupled to a power circuit of a CPU for receiving and amplifying a load voltage of the power circuit, the detecting circuit comprising an output terminal configured for outputting the amplified load voltage; a comparing circuit coupled to the detecting circuit for comparing the amplified load voltage with a default voltage, the comparing circuit comprises: a first comparator; a second comparator; a third comparator; a fourth comparator; and four voltage dividing circuits corresponding to the first, second, third, and fourth comparators; each of the first, second, third, and fourth comparators having a non-inverting terminal coupled to the output terminal of the detecting circuit, and an inverting terminal coupled to a corresponding one of the four voltage dividing circuits; and an adjusting circuit coupled between the comparing circuit and the CPU for selecting a CPU frequency according to a result of the comparison.