Copper and Multi-Mode Fiber Cables ... Single Ended. Differential. Comments.
Modulator. In development. In mass ... World First Single Chip 40G/100G MZ.
40G/100G Mach-Zehnder Modulator Driver Technology
Loi Nguyen
Outline
Introduction 40G DQPSK technology Modulator driver technology Surface mount packaging technology Summary
Page 2
Inphi Proprietary and Confidential
Megatrend: Increasing Bandwidth Demand IP Traffic in Exabytes (1e18) per Month 50.0
60%
45.0
Enterprise
40.0
Consumer
35.0
Video
50% 40%
30.0 25.0
30%
20.0 20%
15.0 10.0
10%
5.0 0.0
0% 2005
Multi-Media
2006
2007
2008
2009
2010
2011
2012
Source; Cisco Systems 2007
• More contents from more sources
Data Voice
• Consumers expect higher quality of experience • Video will be 50% of IP traffic by 2012
Page 3
(Source: Qualcomm Jefferies Conference Oct ’07)
• Explosion in bandwidth demand puts severe pressure on network infrastructures
Megatrend: Serial Data Faster and Farther
30 Gb/s
100GbE FC16X (14.5Gb) 10 Gb/s
5 Gb/s
PCIe Gen3 (8Gb) FBDIMM2 (4.8-9.6Gb) SAS/SATA Gen3 (6Gb) USB 3.0 PCIe Gen2 (1 m) (5Gb)
FC8X (8.5Gb)
FBDIMM1 (3.2Gb+) SAS/SATA Gen2 (3Gb)
FC4X (4.25Gb)
1 Gb/s
Computers & Storage
PCIe Gen2 (30 m)
FR4 Circuit Boards 0
Copper and Multi-Mode Fiber Cables
1m
10m
100m
Single Mode Fiber
1km
10km
Distance 100km
PCI-Express USB3.0, Serial-ATA Fibre Channel Computers
Server racks
Storage farms 10G and 40G SONET 10GbE and 100GbE
Telecom Line Cards Page 4
10GbE
Between Racks
Between buildings
Metro
Long Haul
40G/100G Optical Networking
40G deployment began in 2006, 100G deployment is expected by 2011 “Client side” uses 40G VSR to interface with routers “Line side” uses 40G DWDM to increase national backbone network capacity, typically with reach > 1,000 km 40G DWDM requires external Mach-Zehnder modulators and drivers 40G VSR 10GE=> 40GE/100GE
10G => 40G DWDM => 100G DWDM
10G DWDM => 40G DWDM Page 5
40G DWDM Modulation Formats
Inphi 2514DZ
20G
20G 2:16 DEMUX CDR
I
Inphi 4335TA
Inphi 4335TA
Inphi 2514DZ Q
Balanced PDs Balance d PDs
Fiber Out
Performance
16:2 MUX CMU
DQPSK
RZ Pulse Carver
DQPSK Modulator
Laser
CLK
DEMOD Fiber In
DPSK
ODB
Time
40G DQPSK is the latest and most advanced modulation format Most spectral efficient Most resilient to PMD and OADM filtering tolerance Ramping to production now! Page 6
40G QPSK Signal Mapping I(k) QPSK Modulator
Eout
Q(k)
Modulator Transfer Curve
Vin Vp
(I,Q)=(1,0)
(I,Q)=(0,0)
Vp
2*Vp = 8Vpp
q
(I,Q)=(1,1)
(I,Q)=(0,1)
40G DQPSK modulators require drivers with 8Vpp output swing Page 7
Key Considerations for Modulator Drivers Two major architectures – “Microwave” distributed / traveling wave amplifiers (TWAs) – Switching drivers based on differential pair circuits
2*Vp Vp
Commonly used for single ended design, output transistors need to deliver 2*Vp output swing Page 8
Commonly used for differential design, output transistors need to deliver Vp output swing only
Differential design is preferable from reliability point of view
Reliability Consideration
Breakdown Voltage( BV)
GaAs Breakdown Voltage vs. Cutoff Frequency
20 18 16 14 12 10 8 6 4 2 0
Typical breakdown voltage for 0.15-mm
Single ended drive
Differential drive
0
20
40
60 ft (GHz)
Page 9
80
100
Fundamental tradeoffs between breakdown voltage and speed High speed Si and SiGe cannot be used due to low breakdown voltages (< 4V) GaAs PHEMT with 0.15-mm gate is the preferred technology with breakdown voltage from 10 to 14V Single-ended drive operates close to breakdown voltage Differential drive solves this problem by operating in pushpull configuration, resulting in significantly more margin
Differential vs. Single Ended Single Ended
Differential
Comments
Modulator
In development
In mass production with multiple sources, requires 8Vpp min over all conditions
Differential drive dominates
Modulator Driver Output Swing
7.5 Vpp typical, difficult to achieve >8Vpp over all conditions
Operating in push-pull, 9.5Vpp typical, > 8Vpp over all conditions
Differential drive dominates
GPPO Package
Fewer GPPO connectors required
Need 2X the number of GPPO connectors
Single ended has advantage
SMT Package
Difficult to run high speed traces on board
Best for high speed traces on board at >20 Gbps
30Gbps operation on Roger boards is proven by Inphi
Page 10
2514DZ: Differential Output Swing
40G DQPSK modulators require 8Vpp over temp and voltage
To meet this requirement, drivers need to deliver >9Vpp typical
Difficult to achieve in single-ended design without compromising long term reliability
Differential drivers solve this problem by operating in push-pull configuration
Page 11
Modulator Spec > 8Vpp
40G DQPSK Optical Transmitter pie/2
bias 1
CW
bias 3
optical bias feedback
bias 2 bias1 bias2 bias3
Bias controller 2514DZ
2514DZ
SMI MUX
40G DQPSK optical eye
40G DQPSK MUX, Courtesy of SMI Page 12
40G DQPSK Modulator, Courtesy of SOCC
40G DQPSK Transponder Evolution Smaller Size Lower Power Lower Cost
12.5X4.3” 2007 Metal package with GPPO discrete components
5X7” Now Metal package with GPPO More integrated components
3.5X4.5” Near Future
Surface Mount Technology Highly integrated components Page 13
40G/100G Differential Modulator Driver Roadmap • • • •
Largest Output Swing High Reliability Smaller Size Lower Cost
2006 2008
ES Sampling Now Page 14
Benefits of Inphi Modulator Driver Solutions Largest output swing – Works seamlessly with leading modulators and MUX
High performance – Field proven for both 40G DQPSK and 100G Dual Polarization QPSK applications
High reliability – Differential solution results in ½ voltage stress on individual transistors relative to competing single-ended solutions
Small size – SMT package, 7X7mm2, 90% reduction in footprint relative to current GPPO package Page 15
Inphi 25G SMT Packaging Technology Field proven, in mass production since 2002 Fast rise/fall times, 12 ps typical Low jitter, 2 ps typical Well suited for 40G DQPSK and 100G DP-QPSK applications 25G Eye Diagram on PC Board
25G D Flip Flop in 7X7 mm2 ceramic LGA package Page 16
2811DZ: 40G/100G Modulator Driver in SMT Package
Applications –
40G DQPSK
–
100G DP-QPSK
Benefits –
Small size, 90% reduction in footprint
–
Largest output swing, capable of driving all leading MZ modulators
–
Unique, patented true differential architecture => no skews between I & Q
–
Lower cost than current solutions in metal package with GPPO connectors
Package Length (mm) Width (mm) 2 Footprint Area (mm )
World First Single Chip 40G/100G MZ driver in 7X7 mm2 SMT package
2514DZ 2811DZ % Reduction GPPO SMT 20.3 7.0 66% 22.3 7.0 69% 452.7
49.0
89% Evaluation Board with Dual 2811DZs
Page 17
Summary 40G market is healthy, driven by strong consumer bandwidth demand and IP traffic Inphi broadband analog solutions enable 40G/100G broadband connectivity Inphi is driving the ecosystem to transition from large and expensive metal package with GPPO to compact, lower cost SMT solutions
Page 18
