Patent ID: 11868173
Assignee: MARVELL ASIA PTE LTD
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. An integrated circuit device (IC) having functional circuitry driven by a clock signal, the IC comprising onboard clock generation circuitry, the onboard clock generation circuitry comprising:
an input configured to accept a frequency reference signal;
at least one variable loading capacitor coupled to the input for converting the frequency reference signal into a calibrated clock signal;
calibration circuitry configured to calibrate the at least one variable loading capacitor based on a reference voltage, the calibration circuitry including:
a source of constant reference voltage,
a source of constant current, and
a pair of complementary switches coupled to the constant current source and to a variable reference capacitor, the complementary switches configured to be clocked according to the frequency reference signal to act as a resistor to convert the constant current to a derived voltage that charges a selected variable capacitor; and
trimming circuitry configured to convert the derived voltage into the calibrated clock signal.