Fast wideband frequency comparator
AssigneeElectronics and Telecommunications Research Institute
InventorsHui Dong Lee, Jae Ho Jung
Life of this patent
Estimating the term…
Abstract
A frequency comparator outputs an input reference signal and a comparison target signal as pulse-form signals, and is charged or discharged with a voltage corresponding to the reference signal to output a reference voltage having a variable first frequency range, and charged or discharged with a voltage corresponding to the comparison target signal to output a comparison target voltage having a variable second frequency range. The frequency comparator compares the reference voltage having the first frequency range and the comparison output voltage having the second frequency range.
Claims20
A frequency comparator comprising:
- a pulse generation unit that outputs a reference signal and a comparison target signal as pulse-form signals;
- a capacitor circuit including:
- an operator performing a logical NOR operation on the reference signal and the comparison target signal to output an operation signal, the operation signal being a result of the NOR operation of the reference signal and the comparison target signal;
- and
- first and second capacitor units, the first and second capacitor units being charged according to the operation signal, the first capacitor unit being discharged according to the reference signal output from the pulse generation unit to output a reference voltage having a variable first frequency range, the second capacitor unit being discharged according to the comparison target signal output from the pulse generation unit to output a comparison target voltage having a variable second frequency range;
- and
- a voltage comparison unit that compares the reference voltage and the comparison output voltage, which are output from the capacitor circuit, to output a comparison result signal.
A frequency comparator comprising:
- a reference signal generation unit that generates a first reference signal having a reference frequency based on an externally input signal and outputs the first reference signal to a pulse generation unit;
- the pulse generation unit that outputs a comparison target signal and a second reference signal that is a pulse-form signal corresponding to the first reference signal;
- a capacitor unit including:
- an operator performing a logical NOR operation on the second reference signal and the comparison target signal to output an operation signal, the operation signal being a result of the NOR operation of the second reference signal and the comparison target signal;
- and
- a plurality of first capacitors and a plurality of second capacitors, the first capacitors and the second capacitors being charged according to the operation signal, the first capacitors being discharged according to the second reference signal output from the pulse generation unit to output a reference voltage, the second capacitors being discharged according to the comparison target signal output from the pulse generation unit to output a comparison target voltage;
- and
- a voltage comparison unit that compares the reference voltage and the comparison output voltage, which are output from the capacitor unit, to output a comparison result signal,
- wherein the plurality of first capacitors are connected in parallel with each other, and a first frequency range of the reference voltage varies as the first capacitors are charged or discharged, and the plurality of second capacitors are connected in parallel with each other, and a second frequency range of the comparison target voltage varies as the second capacitors are charged or discharged.
Dependencies are inferred from the claim text.