Credo Technology Group Limited

Xike Liu

Runsheng He

Yifei Dai

Chan Ho Yeung

Lawrence Chi Fung Cheng

Kuan Peng

Xiangxiang Ye

Mengying Ma

Xin Wang

Zhining Li

Lawrence (Chi Fung) Cheng

Rui Gao

Kei Peng

YiFei Dai

Gaige Mei

Shuiqing Huang

To reduce crosstalk between bond wires, one illustrative integrated circuit includes an array of photoemitters arranged along a centerline, with adjacent photoemitters having contact pads on opposite sides of the centerline. An illustrative assembly includes an integrated circuit chip having an array of photoemitter contact pads; a printed circuit board having a recess in which the integrated circuit chip is mounted; and bond wires connecting the contact pads with respective contact pads on the printed circuit board. An illustrative cable connector includes a module that optically couples optical fibers to an array of photoemitters on an integrated circuit chip mounted to a printed circuit board. Each photoemitter has contact pads connected to the printed circuit board contact pads by bond wires, the bond wires for each photoemitter being routed in an opposite direction relative to the bond wires for any adjacent photoemitters in the array.

High frequency signal coupling to surface emitters

An illustrative embodiment of a packaged integrated circuit includes: an integrated circuit chip having a SerDes signal pad; and a package substrate having a core via and an arrangement of micro-vias connecting the SerDes signal pad to an external contact for solder ball connection to a PCB trace. The core via has a first parasitic capacitance, the solder ball connection is associated with a second parasitic capacitance, and the arrangement of micro-vias provides a pi-network inductance that improves connection impedance matching. An illustrative method embodiment includes: obtaining an expected impedance of the PCB trace; determining parasitic capacitances of a core via and a solder ball connection to the PCB trace; minimizing the core via capacitance; calculating a pi-network inductance that improves impedance matching with the PCB trace; and adjusting a micro-via arrangement between the core via and the solder ball connection to provide the pi-network inductance.

Package interface with improved impedance continuity

Connector paddle cards are provided with an improved wiring connection geometry that reduces impedance mismatch. One illustrative embodiment is a printed circuit board having, on at least one surface: edge connector traces arranged along a first edge for contacting electrical conductors in a socket connector; an outer set of electrodes arranged parallel to a second edge for attaching exposed ends of sheathed wires in a cable ('outer wires'); and an inner set of electrodes arranged parallel to the second edge for attaching exposed ends of sheathed wires in a cable ('inner wires'), with the electrodes in the inner set being staggered relative to the electrodes in the outer set.

Connector paddle card with improved wiring connection geometry

Illustrative impedance matching circuits and methods provide enhanced performance without meaningfully increasing cost or areal requirements. One illustrative integrated circuit embodiment includes: a pin configured to connect to a substrate pad via a solder bump having a parasitic capacitance; an inductor that couples the pin to a transmit or receive circuit; a first electrostatic discharge (ESD) protection device electrically connected to a pin end of the inductor; and a second ESD protection device electrically connected to a circuit end of the inductor, where the first ESD protection device has a first capacitance that sums with the parasitic capacitance to equal a total capacitance coupled to the circuit end of the inductor.

Compensation network for high speed integrated circuits

Integrated circuits such as multi-channel receivers may require loop inductors resistant to electromagnetic field interference. Such loop inductors may include multiple non-overlapping loops each defining a corresponding dipole, the multiple dipoles summing to zero, with at least one of said loops having unequal areas. The multiple non-overlapping loops may include: a center loop defining a central magnetic dipole; and a plurality of peripheral loops equally spaced around a perimeter of the center loop, each peripheral loop defining a peripheral magnetic dipole oriented opposite the central magnetic dipole, the plurality of peripheral loops substantially canceling a field from the central magnetic dipole. The total number of loops may be odd, with particular embodiments of three, five, and seven loop designs disclosed. Single and multi-turn embodiments are provided.

Enhanced inductors suitable for integrated multi-channel receivers

Disclosed microelectronic assemblies employ an integrated interposer cage to reduce electromagnetic interference with (and from) high-frequency components. One illustrative embodiment includes: at least one IC die having drive cores for a plurality of oscillators, the IC die attached in a flip-chip configuration to a (interposer) substrate, the substrate having: multiple inductors electrically coupled to said drive cores and each enclosed within a corresponding conductive cage integrated into the substrate to reduce mutual coupling between the inductors and noise coupled through substrate. An illustrative interposer embodiment includes: upper contacts arranged to electrically connect with micro bumps on at least one IC die; metallization and dielectric layers that form multiple inductors each surrounded by bars of a conductive cage; lower contacts arranged to electrically connect with bumps on a package substrate; and a substrate with a plurality of TSVs (through-silicon vias) that electrically couple to the lower contacts. Each of the bars includes: at least one of said TSVs, at least one via through the metallization and dielectric layers, and at least one upper contact.

Cage-shielded interposer inductances

A package trace design technique provides at least partial cancelation of reflections. In one illustrative method of providing a high-bandwidth chip-to-chip link with a first die coupled to a second die via a first substrate trace, an intermediate trace, and a second substrate trace, the method includes: (a) determining a first propagation delay for an electrical signal to traverse the first substrate trace, the electrical signal having a predetermined symbol interval; (b) determining a second propagation delay for the electrical signal to traverse the second substrate trace; and (c) setting a length for at least one of the first and second substrate traces, the length yielding a difference between the first and second propagation delays, the difference having a magnitude equal to half the predetermined symbol interval.

Reflection-canceling package trace design

A multichannel receiver includes multiple receiver modules, each having: a voltage-controlled oscillator that generates a clock signal with a controllable frequency; a phase interpolator that applies a controllable phase shift to the clock signal to provide a sampling signal; a sampling element that produces a digital receive signal by sampling an analog receive signal in accordance with the sampling signal; a timing error estimator that operates on the digital receive signal to provide timing error estimates; a phase control filter that derives, from the timing error estimates, a phase control signal supplied to the phase interpolator, wherein the phase control signal minimizes a phase error between the sampling signal and the analog receive signal; and a frequency control filter that derives, from the timing error estimates, a frequency control signal for controlling the clock signal frequency, wherein the frequency control signal minimizes a frequency offset between the clock signal and the analog receive signal.

Growing community of inventors

Shanghai, China

Xike Liu