Qualcomm Incorporated

Analog Devices,inc.

William Frederick Ellersick

Louis J Nervegna

Jennifer Lloyd

Daniel J Mulcahy

In accordance with the present disclosure, a multi-modulus divider (MMD) circuit configured for operation at high frequencies may include a cascade of multiple divide-by-2-or-3 cells that divides an input clock signal to produce a pulse signal. The MMD circuit may also include a pulse stretching circuit that extends the duration of the pulse signal, thereby outputting an output clock signal. The cascade of divide-by-2-or-3 cells and the pulse stretching circuit may be implemented using full-swing complementary metal-oxide-semiconductor (CMOS) circuits. Each divide-by-2-or-3 cell may be organized so that a critical path of the divide-by-2-or-3 cell comprises a first dynamic flip flop, a second dynamic flip flop, and no more than two logic stages between the first dynamic flip flop and the second dynamic flip flop.

Low power radio frequency divider

An active over-voltage clamp system includes at least one over-voltage detector that is responsive to an input voltage and provides a first current. The system also includes a replica over-voltage circuit that provides a second current, and circuitry subtracting the second current from the first current to produce a difference current. The system further includes a differential clamp activated in response to the difference current. The differential clamp prevents the input voltage from increasing beyond a target voltage.

Voltage clamp

Equalization techniques in clock recovery receivers may include use of a passive equalizer prior to amplification, combined frequency paths in and active and/or passive equalizer, capacitive degeneration and/or negative feedback with low-pass filtering in an active equalizer, a decision feedback equalizer with multiple decision paths, and programmable tail currents to change switching points. A compensation circuit for a pre/post equalizer may include an oscillator fabricated from replica components to compensate for process variations and a look-up table to provide process variation correction in response to programmed equalizer settings.

Equalization in clock recovery receivers

A system and method of calibration develops a function from which is generated a monotonic time response; a gating period is defined from the monotonic time response and any error in the frequency of a reference signal is determined during the gating period; from that error an error signal is generated for adjusting the time constant of a circuit to be calibrated.

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Sudbury, MA, United States of America

William Frederick Ellersick