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AssigneeMotorola, Inc.
InventorsThomas P. Bushey, Jeremy W. Moore, Morgan Fitzgibbon
Estimating the term…
A charge pump arrangement for a phase-locked-loop has a current source circuit (60) which provides charging current to the phase locked loop, and a current sink circuit (90) which depletes charging current from the phase locked loop. The current source circuit (60) and the current sink circuit (90) have slew rates which have a predetermined relationship. In this way, the charge pump causes substantially no non-linear charge injection in the phase-locked-loop. Cascoded current mirrors (75, 85) are utilised to provide a high voltage with thin gate oxide technology. The arrangement has a relatively small die size. Since bias currents of the arrangement are mirrored according to the output current required, improved transient times are produced, leading to reduced phase noise.
A charge pump for a phase locked loop arrangement, the charge pump comprising:
The charge pump, phase-locked-loop arrangement or mobile transceiver of any preceding claim wherein the charge pump further comprises first and second transistors coupled in cascode arrangement between the current source circuit and the current sink circuit.
A method for providing charge regulation for a phase locked loop arrangement, comprising the steps of:
The charge pump, phase-locked-loop arrangement, mobile transceiver or method of any preceding claim wherein the current source circuit and the current sink circuit each have switching transistors arranged to be switched via their source electrodes.
The charge pump, phase-locked-loop arrangement, mobile transceiver or method of any preceding claim wherein the current sink circuit includes a positive feedback arrangement.
The charge pump, phase-locked-loop arrangement, mobile transceiver or method of any preceding claim wherein the phase-locked-loop arrangement is provided for a cellular transceiver.
A phase-locked-loop arrangement substantially as hereinbefore described and with reference to FIGS. 2, 3b and 4 to 6 of the drawings.
A charge pump substantially as hereinbefore described and with reference to FIGS. 2, 3b and 4 to 8 of the drawings.
A mobile transceiver substantially as hereinbefore described and with reference to FIGS. 2, 3b and 4 to 8 of the drawings.
A method substantially as hereinbefore described and with reference to FIGS. 2, 3b and 4 to 8 of the drawings.
Dependencies are inferred from the claim text.