Patent ID: 6184754
Filing Date: 2001-02-06
Classification: H03K

Abstract:
A voltage-controlled oscillator circuit comprising:n (n is an odd integer) inverters connected to each other in a serial connection;a selector control circuit producing a select signal,said selector control circuit containing a selector field-effect transistor,said selector field-effect transistor having a threshold voltage which determines the select signal; anda selector for selecting one of an output signal from an (n-i)-th one (0<i<n) of said n inverters and another output signal from an n-th one of said n inverters in response to the select signal produced by said selector control circuit,wherein said selector supplies the selected signal to a first one of said n inverters,wherein said selector control circuit produces said select signal such that when said threshold voltage of said selector field-effect transistor is smaller than or equal to a preselected value, said selector selects the output signal from said (n-i)-th one of n inverters, and such that when said threshold voltage of said selector field-effect transistor is larger than said preselected value, said selector selects the output signal from said n-th one of n inverters.