DS90CR285, DS90CR286
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DS90CR285/DS90CR286 +3.3V Rising Edge Data Strobe LVDS 28-Bit Channel Link-66 MHz
Check for Samples: DS90CR285,DS90CR286
1FEATURES DESCRIPTION
The DS90CR285 transmitter converts 28 bits of
2 Single +3.3V Supply LVCMOS/LVTTL data into four LVDS (Low Voltage
Chipset (Tx + Rx) Power Consumption <250 Differential Signaling) data streams. A phase-locked
mW (typ) transmit clock is transmitted in parallel with the data
Power-Down Mode (<0.5 mW total) streams over a fifth LVDS link. Every cycle of the
transmit clock 28 bits of input data are sampled and
Up to 231 Megabytes/sec Bandwidth transmitted. The DS90CR286 receiver converts the
Up to 1.848 Gbps Data Throughput LVDS data streams back into 28 bits of
Narrow Bus Reduces Cable Size LVCMOS/LVTTL data. At a transmit clock frequency
of 66 MHz, 28 bits of TTL data are transmitted at a
290 mV Swing LVDS Devices for Low EMI rate of 462 Mbps per LVDS data channel. Using a 66
+1V Common Mode Range (Around +1.2V) MHz clock, the data throughput is 1.848 Gbit/s (231
PLL Requires no External Components Mbytes/s).
Both Devices are Offered in a Low Profile 56- The multiplexing of the data lines provides a
Lead TSSOP Package substantial cable reduction. Long distance parallel
Rising Edge Data Strobe single-ended buses typically require a ground wire
per active signal (and have very limited noise
Compatible with TIA/EIA-644 LVDS Standard rejection capability). Thus, for a 28-bit wide data and
ESD Rating > 7 kV one clock, up to 58 conductors are required. With the
Operating Temperature: 40°C to +85°C Channel Link chipset as few as 11 conductors (4 data
pairs, 1 clock pair and a minimum of one ground) are
needed. This provides a 80% reduction in required
cable width, which provides a system cost savings,
reduces connector physical size and cost, and
reduces shielding requirements due to the cables'
smaller form factor.
The 28 LVCMOS/LVTTL inputs can support a variety
of signal combinations. For example, seven 4-bit
nibbles or three 9-bit (byte + parity) and 1 control.
1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 1999–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
DS90CR285, DS90CR286
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Block Diagram
Figure 1. DS90CR285 - 56-Lead TSSOP Figure 2. DS90CR285 - 56-Lead TSSOP
See Package Number DGG0056A See Package Number DGG0056A
Pin Diagrams for TSSOP Packages
Figure 3. DS90CR285 Figure 4. DS90CR286
See Package Number DGG (R-PDSO-G56) See Package Number DGG (R-PDSO-G56)
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Typical Application
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings (1)(2)
Supply Voltage (VCC)0.3V to +4V
CMOS/TTL Input Voltage 0.3V to (VCC + 0.3V)
CMOS/TTL Output Voltage 0.3V to (VCC + 0.3V)
LVDS Receiver Input Voltage 0.3V to (VCC + 0.3V)
LVDS Driver Output Voltage 0.3V to (VCC + 0.3V)
LVDS Output Short Circuit Duration Continuous
Junction Temperature +150°C
Storage Temperature 65°C to +150°C
Lead Temperature (Soldering, 4 sec.) +260°C
Solder Reflow Temperature Maximum Package Power DS90CR285MTD 1.63 W
Dissipation @ +25°C DS90CR286MTD 1.61 W
Package Derating: DS90CR285MTD 12.5 mW/°C above +25°C
DS90CR286MTD 12.4 mW/°C above +25°C
ESD Rating (HBM, 1.5 k, 100 pF) > 7 kV
(1) “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to
imply that the device should be operated at these limits. “Electrical Characteristics” specify conditions for device operation.
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/ Distributors for availability and specifications.
Recommended Operating Conditions Min Nom Max Units
Supply Voltage (VCC) 3.0 3.3 3.6 V
Operating Free Air Temperature (TA)40 +25 +85 °C
Receiver Input Range 0 2.4 V
Supply Noise Voltage (VCC) 100 mVPP
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Electrical Characteristics
Over recommended operating supply and temperature ranges unless otherwise specified
Symbol Parameter Conditions Min Typ Max Unit
s
LVCMOS/LVTTL DC SPECIFICATIONS
VIH High Level Input Voltage 2.0 VCC V
VIL Low Level Input Voltage GND 0.8 V
VOH High Level Output Voltage IOH =0.4 mA 2.7 3.3 V
VOL Low Level Output Voltage IOL = 2 mA 0.06 0.3 V
VCL Input Clamp Voltage ICL =18 mA 0.79 1.5 V
IIN Input Current VIN = VCC, GND, 2.5V or 0.4V ±5.1 ±10 μA
IOS Output Short Circuit Current VOUT = 0V 60 120 mA
LVDS DRIVER DC SPECIFICATIONS
VOD Differential Output Voltage RL= 100Ω250 290 450 mV
ΔVOD Change in VOD between Complimentary Output 35 mV
States
VOS Offset Voltage(1) 1.125 1.25 1.375 V
ΔVOS Change in VOS between Complimentary Output 35 mV
States
IOS Output Short Circuit Current VOUT = 0V, RL= 100Ω 3.5 5 mA
IOZ Output TRI-STATE Current PWR DWN = 0V, ±1 ±10 μA
VOUT = 0V or VCC
LVDS RECEIVER DC SPECIFICATIONS
VTH Differential Input High Threshold VCM = +1.2V +100 mV
VTL Differential Input Low Threshold 100 mV
IIN Input Current VIN = +2.4V, VCC = 3.6V ±10 μA
VIN = 0V, VCC = 3.6V ±10 μA
TRANSMITTER SUPPLY CURRENT
ICCTW Transmitter Supply Current Worst Case (with RL= 100Ω, f = 32.5 MHz 31 45 mA
Loads) CL= 5 pF, f = 37.5 MHz 32 50 mA
Worst Case Pattern f = 66 MHz 37 55 mA
(Figure 5 Figure 6)
, TA=10°C to +70°C
RL= 100Ω, f = 40 MHz 38 51 mA
CL= 5 pF, f = 66 MHz 42 55 mA
Worst Case Pattern
(Figure 5 Figure 6)
, TA=40°C to +85°C
ICCTZ Transmitter Supply Current Power Down PWR DWN = Low 10 55 μA
Driver Outputs in TRI-STATE
under Powerdown Mode
RECEIVER SUPPLY CURRENT
ICCRW Receiver Supply Current Worst Case CL= 8 pF, f = 32.5 MHz 49 65 mA
Worst Case Pattern f = 37.5 MHz 53 70 mA
(Figure 5 Figure 7)f = 66 MHz 78 105 mA
, TA=10°C to +70°C
CL= 8 pF, f = 40 MHz 55 82 mA
Worst Case Pattern f = 66 MHz 78 105 mA
(Figure 5 Figure 7)
, TA=40°C to +85°C
ICCRZ Receiver Supply Current Power Down PWR DWN = Low 10 55 μA
Receiver Outputs Stay Low during
Powerdown Mode
(1) VOS previously referred as VCM.
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Transmitter Switching Characteristics
Over recommended operating supply and 40°C to +85°C ranges unless otherwise specified
Symbol Parameter Min Typ Max Units
LLHT LVDS Low-to-High Transition Time (Figure 6) 0.5 1.5 ns
LHLT LVDS High-to-Low Transition Time (Figure 6) 0.5 1.5 ns
TCIT TxCLK IN Transition Time (Figure 8) 5 ns
TCCS TxOUT Channel-to-Channel Skew (Figure 9) 250 ps
TPPos0 Transmitter Output Pulse Position for Bit0 f = 40 MHz 0.4 0 0.4 ns
(1)(Figure 20)
TPPos1 Transmitter Output Pulse Position for Bit1 3.1 3.3 4.0 ns
TPPos2 Transmitter Output Pulse Position for Bit2 6.5 6.8 7.6 ns
TPPos3 Transmitter Output Pulse Position for Bit3 10.2 10.4 11.0 ns
TPPos4 Transmitter Output Pulse Position for Bit4 13.7 13.9 14.6 ns
TPPos5 Transmitter Output Pulse Position for Bit5 17.3 17.6 18.2 ns
TPPos6 Transmitter Output Pulse Position for Bit6 21.0 21.2 21.8 ns
TPPos0 Transmitter Output Pulse Position for Bit0 f = 66 MHz 0.4 0 0.3 ns
(2)(Figure 20)
TPPos1 Transmitter Output Pulse Position for Bit1 1.8 2.2 2.5 ns
TPPos2 Transmitter Output Pulse Position for Bit2 4.0 4.4 4.7 ns
TPPos3 Transmitter Output Pulse Position for Bit3 6.2 6.6 6.9 ns
TPPos4 Transmitter Output Pulse Position for Bit4 8.4 8.8 9.1 ns
TPPos5 Transmitter Output Pulse Position for Bit5 10.6 11.0 11.3 ns
TPPos6 Transmitter Output Pulse Position for Bit6 12.8 13.2 13.5 ns
TCIP TxCLK IN Period (Figure 10 )15 T 50 ns
TCIH TxCLK IN High Time (Figure 10) 0.35T 0.5T 0.65T ns
TCIL TxCLK IN Low Time (Figure 10) 0.35T 0.5T 0.65T ns
TSTC TxIN Setup to TxCLK IN (Figure 10) 2.5 ns
THTC TxIN Hold to TxCLK IN (Figure 10) 0 ns
TCCD TxCLK IN to TxCLK OUT Delay @ 25°C,VCC=3.3V (Figure 12) 3 3.7 5.5 ns
TPLLS Transmitter Phase Lock Loop Set (Figure 14) 10 ms
TPDD Transmitter Powerdown Delay (Figure 18) 100 ns
(1) The min. and max. are based on the actual bit position of each of the 7 bits within the LVDS data stream across PVT.
(2) The min. and max. limits are based on the worst bit by applying a 400ps/+300ps shift from ideal position.
Receiver Switching Characteristics
Over recommended operating supply and 40°C to +85°C ranges unless otherwise specified
Symbol Parameter Min Typ Max Units
CLHT CMOS/TTL Low-to-High Transition Time (Figure 7) 2.2 5.0 ns
CHLT CMOS/TTL High-to-Low Transition Time (Figure 7) 2.2 5.0 ns
RSPos0 Receiver Input Strobe Position for Bit 0 (1)(Figure 21) f = 40 MHz 1.0 1.4 2.15 ns
RSPos1 Receiver Input Strobe Position for Bit 1 4.5 5.0 5.8 ns
RSPos2 Receiver Input Strobe Position for Bit 2 8.1 8.5 9.15 ns
RSPos3 Receiver Input Strobe Position for Bit 3 11.6 11.9 12.6 ns
RSPos4 Receiver Input Strobe Position for Bit 4 15.1 15.6 16.3 ns
RSPos5 Receiver Input Strobe Position for Bit 5 18.8 19.2 19.9 ns
RSPos6 Receiver Input Strobe Position for Bit 6 22.5 22.9 23.6 ns
(1) The min. and max. are based on the actual bit position of each of the 7 bits within the LVDS data stream across PVT.
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Receiver Switching Characteristics (continued)
Over recommended operating supply and 40°C to +85°C ranges unless otherwise specified
Symbol Parameter Min Typ Max Units
RSPos0 Receiver Input Strobe Position for Bit 0 (2)(Figure 21) f = 66 MHz 0.7 1.1 1.4 ns
RSPos1 Receiver Input Strobe Position for Bit 1 2.9 3.3 3.6 ns
RSPos2 Receiver Input Strobe Position for Bit 2 5.1 5.5 5.8 ns
RSPos3 Receiver Input Strobe Position for Bit 3 7.3 7.7 8.0 ns
RSPos4 Receiver Input Strobe Position for Bit 4 9.5 9.9 10.2 ns
RSPos5 Receiver Input Strobe Position for Bit 5 11.7 12.1 12.4 ns
RSPos6 Receiver Input Strobe Position for Bit 6 13.9 14.3 14.6 ns
RSKM RxIN Skew Margin (3)(Figure 22) f = 40 MHz 490 ps
f = 66 MHz 400 ps
RCOP RxCLK OUT Period (Figure 11) 15 T 50 ns
RCOH RxCLK OUT High Time (Figure 11) f = 40 MHz 6.0 10.0 ns
f = 66 MHz 4.0 6.1 ns
RCOL RxCLK OUT Low Time (Figure 11) f = 40 MHz 10.0 13.0 ns
f = 66 MHz 6.0 7.8 ns
RSRC RxOUT Setup to RxCLK OUT (Figure 11) f = 40 MHz 6.5 14.0 ns
f = 66 MHz 2.5 8.0 ns
RHRC RxOUT Hold to RxCLK OUT (Figure 11) f = 40 MHz 6.0 8.0 ns
f = 66 MHz 2.5 4.0 ns
RCCD RxCLK IN to RxCLK OUT Delay (Figure 13) f = 40 MHz 4.0 6.7 8.0 ns
f = 66 MHz 5.0 6.6 9.0 ns
RPLLS Receiver Phase Lock Loop Set (Figure 15) 10 ms
RPDD Receiver Powerdown Delay (Figure 19) 1 μs
(2) The min. and max. limits are based on the worst bit by applying a 400ps/+300ps shift from ideal position.
(3) Receiver Skew Margin is defined as the valid data sampling region at the receiver inputs. This margin takes into account the transmitter
pulse positions (min and max) and the receiver input setup and hold time (internal data sampling window). This margin allows LVDS
interconnect skew, inter-symbol interference (both dependent on type/length of cable), and clock jitter less than 250 ps).
AC TIMING DIAGRAMS
Figure 5. “Worst Case” Test Pattern
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Figure 6. DS90CR285 (Transmitter) LVDS Output Load and Transition Times
Figure 7. DS90CR286 (Receiver) CMOS/TTL Output Load and Transition Times
Figure 8. DS90CR285 (Transmitter) Input Clock Transition Time
(1) Measurements at VDIFF = 0V
(2) TCCS measured between earliest and latest LVDS edges.
(3) TxCLK Differential LowHigh Edge
Figure 9. DS90CR285 (Transmitter) Channel-to-Channel Skew
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Figure 10. DS90CR285 (Transmitter) Setup/Hold and High/Low Times
Figure 11. DS90CR286 (Receiver) Setup/Hold and High/Low Times
Figure 12. DS90CR285 (Transmitter) Clock In to Clock Out Delay
Figure 13. DS90CR286 (Receiver) Clock In to Clock Out Delay
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Figure 14. DS90CR285 (Transmitter) Phase Lock Loop Set Time
Figure 15. DS90CR286 (Receiver) Phase Lock Loop Set Time
Figure 16. Seven Bits of LVDS in Once Clock Cycle
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Figure 17. 28 ParalIeI TTL Data Inputs Mapped to LVDS Outputs
Figure 18. Transmitter Powerdown DeIay
Figure 19. Receiver Powerdown Delay
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Figure 20. Transmitter LVDS Output Pulse Position Measurement
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Figure 21. Receiver LVDS Input Strobe Position
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C—Setup and Hold Time (Internal data sampling window) defined by Rspos (receiver input strobe position) min and
max
Tppos—Transmitter output pulse position (min and max)
RSKM Cable Skew (type, length) + Source Clock Jitter (cycle to cycle) + ISI (Inter-symbol interference)
Cable Skew—typically 10 ps–40 ps per foot, media dependent
(1) Cycle-to-cycle jitter is less than 250 ps
(2) ISI is dependent on interconnect length; may be zero
Figure 22. Receiver LVDS Input Skew Margin
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DS90CR285 DGG (TSSOP) Package Pin Description Channel Link Transmitter
Pin Name I/O No. Description
TxIN I 28 TTL level input.
TxOUT+ O 4 Positive LVDS differential data output.
TxOUTO 4 Negative LVDS differential data output.
TxCLK IN I 1 TTL IeveI clock input. The rising edge acts as data strobe. Pin name TxCLK IN.
TxCLK OUT+ O 1 Positive LVDS differential clock output.
TxCLK OUTO 1 Negative LVDS differential clock output.
PWR DWN I 1 TTL level input. Assertion (low input) TRI-STATES the outputs, ensuring low current at power down.
VCC I 4 Power supply pins for TTL inputs.
GND I 5 Ground pins for TTL inputs.
PLL VCC I 1 Power supply pin for PLL.
PLL GND I 2 Ground pins for PLL.
LVDS VCC I 1 Power supply pin for LVDS outputs.
LVDS GND I 3 Ground pins for LVDS outputs.
DS90CR286 DGG (TSSOP) Package Pin Description Channel Link Receiver
Pin Name I/O No. Description
RxIN+ I 4 Positive LVDS differential data inputs.
RxINI 4 Negative LVDS differential data inputs.
RxOUT O 28 TTL level data outputs.
RxCLK IN+ I 1 Positive LVDS differential clock input.
RxCLK INI 1 Negative LVDS differential clock input.
RxCLK OUT O 1 TTL level clock output. The rising edge acts as data strobe. Pin name RxCLK OUT.
PWR DWN I 1 TTL level input.When asserted (low input) the receiver outputs are low.
VCC I 4 Power supply pins for TTL outputs.
GND I 5 Ground pins for TTL outputs.
PLL VCC I 1 Power supply for PLL.
PLL GND I 2 Ground pin for PLL.
LVDS VCC I 1 Power supply pin for LVDS inputs.
LVDS GND I 3 Ground pins for LVDS inputs.
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APPLICATIONS INFORMATION
The Channel Link devices are intended to be used in a wide variety of data transmission applications. Depending
upon the application the interconnecting media may vary. For example, for lower data rate (clock rate) and
shorter cable lengths (< 2m), the media electrical performance is less critical. For higher speed/long distance
applications the media's performance becomes more critical. Certain cable constructions provide tighter skew
(matched electrical length between the conductors and pairs). Twin-coax for example, has been demonstrated at
distances as great as 5 meters and with the maximum data transfer of 1.848 Gbit/s. Additional applications
information can be found in the following Interface Application Notes:
AN = #### Topic
AN-1041 Introduction to Channel Link
(SNLA218)
AN-1108 Channel Link PCB and Interconnect Design-In
(SNLA008) Guidelines
AN-806 Transmission Line Theory
(SNLA026)
AN-905 Transmission Line Calculations and Differential
(SNSNLA035L Impedance
A008)
AN-916 Cable Information
(SNLA219)
CABLES
A cable interface between the transmitter and receiver needs to support the differential LVDS pairs. The 21-bit
CHANNEL LINK chipset (DS90CR215/216) requires four pairs of signal wires and the 28-bit CHANNEL LINK
chipset (DS90CR285/286) requires five pairs of signal wires. The ideal cable/connector interface would have a
constant 100Ωdifferential impedance throughout the path. It is also recommended that cable skew remain below
150 ps (@ 66 MHz clock rate) to maintain a sufficient data sampling window at the receiver.
In addition to the four or five cable pairs that carry data and clock, it is recommended to provide at least one
additional conductor (or pair) which connects ground between the transmitter and receiver. This low impedance
ground provides a common mode return path for the two devices. Some of the more commonly used cable types
for point-to-point applications include flat ribbon, flex, twisted pair and Twin-Coax. All are available in a variety of
configurations and options. Flat ribbon cable, flex and twisted pair generally perform well in short point-to-point
applications while Twin-Coax is good for short and long applications. When using ribbon cable, it is
recommended to place a ground line between each differential pair to act as a barrier to noise coupling between
adjacent pairs. For Twin-Coax cable applications, it is recommended to utilize a shield on each cable pair. All
extended point-to-point applications should also employ an overall shield surrounding all cable pairs regardless
of the cable type. This overall shield results in improved transmission parameters such as faster attainable
speeds, longer distances between transmitter and receiver and reduced problems associated with EMS or EMI.
The high-speed transport of LVDS signals has been demonstrated on several types of cables with excellent
results. However, the best overall performance has been seen when using Twin-Coax cable. Twin-Coax has very
low cable skew and EMI due to its construction and double shielding. All of the design considerations discussed
here and listed in the supplemental application notes provide the subsystem communications designer with many
useful guidelines. It is recommended that the designer assess the tradeoffs of each application thoroughly to
arrive at a reliable and economical cable solution.
BOARD LAYOUT
To obtain the maximum benefit from the noise and EMI reductions of LVDS, attention should be paid to the
layout of differential lines. Lines of a differential pair should always be adjacent to eliminate noise interference
from other signals and take full advantage of the noise canceling of the differential signals. The board designer
should also try to maintain equal length on signal traces for a given differential pair. As with any high speed
design, the impedance discontinuities should be limited (reduce the numbers of vias and no 90 degree angles on
traces). Any discontinuities which do occur on one signal line should be mirrored in the other line of the
differential pair. Care should be taken to ensure that the differential trace impedance match the differential
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impedance of the selected physical media (this impedance should also match the value of the termination
resistor that is connected across the differential pair at the receiver's input). Finally, the location of the CHANNEL
LINK TxOUT/RxIN pins should be as close as possible to the board edge so as to eliminate excessive pcb runs.
All of these considerations will limit reflections and crosstalk which adversely effect high frequency performance
and EMI.
UNUSED INPUTS
All unused inputs at the TxIN inputs of the transmitter must be tied to ground. All unused outputs at the RxOUT
outputs of the receiver must then be left floating.
INPUTS
The TxIN and control inputs are compatible with LVCMOS and LVTTL levels. These pins are not 5V tolerant.
TERMINATION
Use of current mode drivers requires a terminating resistor across the receiver inputs. The CHANNEL LINK
chipset will normally require a single 100Ωresistor between the true and complement lines on each differential
pair of the receiver input. The actual value of the termination resistor should be selected to match the differential
mode characteristic impedance (90Ωto 120Ωtypical) of the cable. Figure 23 shows an example. No additional
pull-up or pull-down resistors are necessary as with some other differential technologies such as PECL. Surface
mount resistors are recommended to avoid the additional inductance that accompanies leaded resistors. These
resistors should be placed as close as possible to the receiver input pins to reduce stubs and effectively
terminate the differential lines.
DECOUPLING CAPACITORS
Bypassing capacitors are needed to reduce the impact of switching noise which could limit performance. For a
conservative approach three parallel-connected decoupling capacitors (Multi-Layered Ceramic type in surface
mount form factor) between each VCC and the ground plane(s) are recommended. The three capacitor values are
0.1 μF, 0.01μF and 0.001 μF. An example is shown in Figure 24. The designer should employ wide traces for
power and ground and ensure each capacitor has its own via to the ground plane. If board space is limiting the
number of bypass capacitors, the PLL VCC should receive the most filtering/bypassing. Next would be the LVDS
VCC pins and finally the logic VCC pins.
Figure 23. LVDS Serialized Link Termination
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Figure 24. CHANNEL LINK
Decoupling Configuration
CLOCK JITTER
The CHANNEL LINK devices employ a PLL to generate and recover the clock transmitted across the LVDS
interface. The width of each bit in the serialized LVDS data stream is one-seventh the clock period. For example,
a 66 MHz clock has a period of 15 ns which results in a data bit width of 2.16 ns. Differential skew (Δt within one
differential pair), interconnect skew (Δt of one differential pair to another) and clock jitter will all reduce the
available window for sampling the LVDS serial data streams. Care must be taken to ensure that the clock input
to the transmitter be a clean low noise signal. Individual bypassing of each VCC to ground will minimize the noise
passed on to the PLL, thus creating a low jitter LVDS clock. These measures provide more margin for channel-
to-channel skew and interconnect skew as a part of the overall jitter/skew budget.
COMMON MODE vs. DIFFERENTIAL MODE NOISE MARGIN
The typical signal swing for LVDS is 300 mV centered at +1.2V. The CHANNEL LINK receiver supports a 100
mV threshold therefore providing approximately 200 mV of differential noise margin. Common mode protection is
of more importance to the system's operation due to the differential data transmission. LVDS supports an input
voltage range of Ground to +2.4V. This allows for a ±1.0V shifting of the center point due to ground potential
differences and common mode noise.
POWER SEQUENCING AND POWERDOWN MODE
Outputs of the CNANNEL LINK transmitter remain in TRI-STATE until the power supply reaches 2V. Clock and
data outputs will begin to toggle 10 ms after VCC has reached 3V and the Powerdown pin is above 1.5V. Either
device may be placed into a powerdown mode at any time by asserting the Powerdown pin (active low). Total
power dissipation for each device will decrease to 5 μW (typical).
The CHANNEL LINK chipset is designed to protect itself from accidental loss of power to either the transmitter or
receiver. If power to the transmit board is lost, the receiver clocks (input and output) stop. The data outputs
(RxOUT) retain the states they were in when the clocks stopped. When the receiver board loses power, the
receiver inputs are shorted to V CC through an internal diode. Current is limited (5 mA per input) by the fixed
current mode drivers, thus avoiding the potential for latchup when powering the device.
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Figure 25. Single-Ended and Differential Waveforms
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REVISION HISTORY
Changes from Revision B (March 2013)