US 5,691,669 A · Dual adjust current controlled phase locked loop

Abstract

A dual adjust current-controlled phase locked loop is provided for allowing multiple-gain frequency acquisition of a signal. The dual adjust current-controlled phase locked loop includes a phase detector responsive to a reference signal and a synthesized signal for producing a phase error signal; a controller responsive to the phase error signal for generating coarse and fine adjust control signals; and a dual adjust current-controlled oscillator responsive to the coarse and fine adjust control signals for adjusting the oscillating frequency of the synthesized signal. The dual adjust current controlled oscillator includes a differential current controlled ring oscillator comprising a series of delay elements. Each delay element includes a high gain circuit responsive to the coarse adjust control signal and a low gain circuit responsive to the fine adjust control signal.

Claims18

Dependent claims

A dual-adjust current controlled oscillator, comprising:

one or more delay elements arranged in a ring to produce an oscillating output signal,
each delay element producing an output signal at a first output node and a complemented output signal at a second output node, and each delay element being responsive to an input signal at a first input node, a complemented input signal at a second input node,
each delay element comprising a high gain current source directly coupled to said first output node and said second output node, said high gain current source coupled to receive a coarse adjust control signal for controlling a frequency range level of an oscillating frequency range of the output signal and the complemented output signal, and
each delay element comprising a low gain current source directly coupled to said first output node and said second output node, said low gain current source coupled to receive a fine adjust control signal for controlling a frequency of the output signal and complemented output signal, said frequency being within the oscillating frequency range.

1 more element

A method for controlling a dual-adjust current-controlled oscillator, the dual-adjust current-controlled oscillator responsive to a coarse adjust control signal for controlling a range level of an oscillating frequency range and a fine adjust control signal for producing a synthesized signal having an oscillating frequency within the oscillating frequency range, the method comprising the steps of:

(a) comparing the synthesized signal with a reference signal;
(b) generating the coarse adjust control signal and the fine adjust control signal, the coarse adjust control signal reflecting a coarse magnitude and a coarse direction for controlling the range level of the oscillating frequency range and for providing high gain regulation of the oscillating frequency of the synthesized signal, and the fine adjust control signal reflecting a fine magnitude and a fine direction for providing low gain regulation of the oscillating frequency of the synthesized signal.

A phase locked loop for providing multiple-gain frequency acquisition of a signal, comprising:

a phase detector responsive to a reference signal and a synthesized signal for producing a phase error signal;
a controller responsive to the phase error signal for generating a coarse adjust control signal and a fine adjust control signal;
and
a dual adjust current-controlled oscillator for producing the synthesized signal, said dual adjust current-control oscillator being responsive to the coarse adjust control signal for controlling a range level of an oscillating frequency range of the synthesized signal and the fine adjust control signal for controlling an oscillating frequency of the synthesized signal, wherein the oscillating frequency is within the oscillating frequency range.

1 more element

Dependencies are inferred from the claim text.

Dual adjust current controlled phase locked loop

Life of this patent

Dual adjust current controlled phase locked loop

Life of this patent

Abstract

Claims18