High Speed Interconnect Solutions HIROSE ELECTRIC IT3-32mm SI Report Three-Piece Mezzanine Connector for 20+ Gbps Applications October 29, 2009

High Speed Interconnect Solutions Outline  What is IT3  HFSS simulation models for connector and via  Insertion and return losses, NEXT, FEXT, and impedance profile  Insertion loss to crosstalk ratio (ICR)  Fully populated vs. 50% density  Connector-only vs. full channel  Eye diagrams  Summary  Appendix  Measurement vs. simulation correlation  Measured ICR for IT3-25mm

High Speed Interconnect Solutions What is IT3  Proven 3-piece design for improved electrical performance and mechanical reliability SignalGround Interposer Signal / Ground configuration Mating side Mating / unmating Locking latch Mating receptacle IT3D-***S-BGA(**) Interposer assembly Mounting side Installed and locked Mounting receptacle IT3M-***S-BGA(**)

High Speed Interconnect Solutions HFSS simulation model  A.s60p file was created, and the differential pair’s response was examined. Only a quadrant of model is shown Signal pin Ground pin Differential pairs

High Speed Interconnect Solutions Via model  A.s60p Touchstone file was also created to study the effect of via stub and coupling.

High Speed Interconnect Solutions IEEE 802.3ap channel spec.  IEEE 802.3ap defined the channel spec. of insertion- loss-to-crosstalk ratio (ICR) up to 5 GHz for 10 Gbps data rate. We will extrapolate this ICR curve to 10 GHz for 20 Gbps data rate. 10 GHz (for 20 Gbps)

High Speed Interconnect Solutions Connector’s ICR  The connector and via transition’s contribution to ICR is independent of channel length, because the insertion loss and crosstalk attenuate at the same rate. Board A Board B Insertion loss FEXT Board A Board B Insertion loss NEXT ICR wrt. FEXT: ICR wrt. NEXT: Connector and via transition is assumed to be at approximately the middle of channel.

High Speed Interconnect Solutions IT3-32mm connector-only response (Fully populated) Impedance and GHz  All insertion and return losses, and NEXT and FEXT are shown.

High Speed Interconnect Solutions IT3-32mm connector-only response (60% density)  Both NEXT and FEXT are reduced, if some pins are skipped (i.e., terminated or assigned to low-speed signals).

High Speed Interconnect Solutions 10 High Speed Interconnect Solutions IT3-32mm connector-only response (50% density)  Even less NEXT and FEXT with 50% density.

High Speed Interconnect Solutions 11 High Speed Interconnect Solutions rise time (20% to 80%)  IT3’s receptacles were designed to have slightly high impedance to offset the via’s and via stub’s low impedance. Connector onlyConnector + ~60mil via stubs

High Speed Interconnect Solutions 12 High Speed Interconnect Solutions ICR in a full channel (Fully populated)  ICR with 14-aggressor connector and via FEXT, and ~60 mil stub meets the extrapolated IEEE 802.3ap spec. for 20 Gbps. 6” IT3 120 mil FR mil stub Via model FEXT for via-connector-via (w/o trace attenuation) ICR with 14 FEXTs 20 Gbps

High Speed Interconnect Solutions 13 High Speed Interconnect Solutions ICR in a full channel (50% density)  ICR with 6-aggressor connector and via FEXT, and ~60 mil stub gives plenty of Gbps, as compared to the extrapolated IEEE 802.3ap spec. 6” IT3 120 mil FR mil stub Via model ICR with 6 FEXTs 20 Gbps FEXT for via-connector-via (w/o trace attenuation)

High Speed Interconnect Solutions 14 High Speed Interconnect Solutions Channel Gbps (Fully populated)  ADS simulation with 3-tap TX equalization gives good open Gbps with ~60mil via stub and 14 FEXT included. Without connector Jitter = 15.06ps Eye Height = mV With connector and 14 FEXT Jitter = 18.57ps Eye Height = mV 6” IT3 120 mil FR mil stub Via model

High Speed Interconnect Solutions 15 High Speed Interconnect Solutions Channel Gbps (50% density)  ADS simulation with 3-tap TX equalization gives good open Gbps with ~60mil via stub and 6 FEXT included. Without connector Jitter = 12.44ps Eye Height = mV With connector and 6 FEXT Jitter = 18.48ps Eye Height = mV 6” IT3 120 mil FR mil stub Via model

High Speed Interconnect Solutions 16 High Speed Interconnect Solutions Channel Gbps (50% density)  ADS simulation with 7-tap TX equalization gives good open Gbps with ~60mil via stub and 6 FEXT included. Without connector Jitter = 12.89ps Eye Height = mV With connector and 6 FEXT Jitter = 19.39ps* Eye Height = mV* 6” IT3 120 mil FR mil stub Via model *Degradation is mainly due to via stubs.

High Speed Interconnect Solutions 17 High Speed Interconnect Solutions Summary  IT3 meets the extrapolated IEEE802.3ap’s ICR spec. for 20+ Gbps.  Both characterization and demo boards are available for evaluation.

High Speed Interconnect Solutions HIROSE ELECTRIC Appendix A Measurement vs. simulation correlation

High Speed Interconnect Solutions 19 High Speed Interconnect Solutions Measurement Setup  To measure the connector’s performance directly, we pre-characterized and de-embedded the test boards. - = Connector + Test BoardsBottom Test BoardTop Test BoardConnector Only Bottom test board Top test board -

High Speed Interconnect Solutions 20 High Speed Interconnect Solutions Insertion and return losses  Good correlation in differential insertion and return losses.

High Speed Interconnect Solutions 21 High Speed Interconnect Solutions NEXT  Good correlation in differential NEXT.

High Speed Interconnect Solutions 22 High Speed Interconnect Solutions FEXT  Good correlation in differential FEXT.

High Speed Interconnect Solutions HIROSE ELECTRIC Appendix B Measured ICR for IT3-25mm

High Speed Interconnect Solutions 24 High Speed Interconnect Solutions Test board  VNA measurements were taken on 120mil test boards with IT3-25mm connector, 2 via transitions, and 6”+6” PCB traces routed through the middle layers. * The ICR curves in the following slides will also be valid for other trace length.

High Speed Interconnect Solutions 25 High Speed Interconnect Solutions Optimized 60% density for 20 Gbps  IT3 meets ICR spec. (with FEXT) for 20 Gbps if 40% pins are “skipped”. ICR wrt. NEXT*ICR wrt. FEXT* * These curves include 8 aggressors for one IT3-25mm connector and two via transitions. The skipped pins are terminated in this case. “Skipped” pins Victim pair W U R N L J G E C A