Texas Instruments Corporation

Wenting Zhou

Ali Kiaei

Reza Hoshyar

Ahmad Reza Bahai

Baher S Haroun

Nirmal Chindhu Warke

Kevin Zheng

Kai Yiu Tam

A high linearity phase interpolator (PI) is disclosed. A phase value parameter indicative of a desired phase difference between an output signal and an input clock signal edge may be provided by control logic. A first capacitor may be charged for a first period of time with a first current that is proportional to the phase value parameter to produce a first voltage on the capacitor that is proportional to the phase value parameter. The first capacitor may be further charged for a second period of time with a second current that has a constant value to form a voltage ramp offset by the first voltage. A reference voltage may be compared to the voltage ramp during the second period of time. The output signal may be asserted at a time when the voltage ramp equals the reference voltage.

High linearity phase interpolator

Disclosed examples include fractional frequency divider circuits, including a counter to provide phase shifted pulse output signals in response to counting of an adjustable integer number Ncycles of an input clock signal, an output circuit to provide an output clock signal having a first edge between first edges of the pulse output signals, as well as a delta-sigma modulator (DSM), clocked by the second pulse output signal to receive a first predetermined value and to provide a DSM output value, and a phase accumulator to receive a step input value representing a sum of the DSM output value and a second predetermined value. The phase accumulator provides a divisor input signal to the counter, and provides a phase adjustment value to the output circuit to control the position of the first edge of the output clock signal between the first edges of the pulse output signals.

Fractional frequency clock divider with direct division

A Continuous Time Linear Equalizer (CTLE) and a method of operating a CTLE in a receiver for a Pulse Amplitude Modulation (PAM) signal are disclosed. The method includes initiating equalization using an initial equalization setting that is optimized to meet a first objective and responsive to a determination, shifting to a final equalization setting that is optimized to meet a second objective.

CTLE gear shifting to enable CDR frequency lock in wired communication

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Milpitas, CA, United States of America

Wenting Zhou