Patent ID: 11870448
Assignee: TEXAS INSTRUMENTS INCORPORATED
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. A clock controlled system comprising:
a phase frequency detector (PFD) and charge pump (CP) having an output and:
a first current source configured to provide a first current at a first current source output responsive to a center frequency of a PLL bandwidth;
a second current source configured to provide a second current at a second current source output responsive to the center frequency;
a first D flip flop (DFF) having a first DFF input and a first DFF output;
a second DFF having a second DFF input and a second DFF output, wherein the second DFF input is configured to receive an input clock signal; and
the PFD and CP configured to provide a third current at the output of the PFD and CP responsive to the first current, the second current, and a phase difference between the first DFF input and the second DFF input;

a compensation circuit including:
a resistive element having a resistance responsive to the center frequency; and
a capacitor circuit coupled to the resistive element;

a transconductance circuit including:
a third current source configured to provide a fourth current at a third current source output responsive to the center frequency; and
an error amplifier having a reference input, first and second amplifier inputs and an amplifier output, wherein the error amplifier has a transconductance responsive to the center frequency, the first amplifier input is coupled to the first current source output, the second amplifier input is coupled to the capacitor circuit, and the error amplifier is configured to receive a signal at the second amplifier input responsive to the third current and the resistance; and

an oscillator having an oscillator input and an oscillator output, wherein the oscillator input is coupled to the amplifier output, the oscillator output is coupled to the first DFF output, and the oscillator is configured to provide a signal at the oscillator a output for generating a feedback signal.