NSC DS92LV0421SQ 10 - 75 mhz channel link ii serializer/deserializer with lvds parallel interface Datasheet

DS92LV0421 / DS92LV0422
May 26, 2010
10 - 75 MHz Channel Link II Serializer/Deserializer with
LVDS Parallel Interface
General Description
Features
The DS92LV0421 (serializer) and DS92LV0422 (deserializer)
chipset translates a Channel Link LVDS video interface (4
LVDS Data + LVDS Clock) into a high-speed serialized interface over a single CML pair.
The DS92LV0421 and DS92LV0422 enable applications that
currently use the popular Channel Link or Channel Link style
devices to seamlessly upgrade to an embedded clock interface to reduce interconnect cost or ease design challenges.
The parallel LVDS interface also reduces FPGA I/O pins,
board trace count and alleviates EMI issues, when compared
to traditional single-ended wide bus interfaces.
Programmable transmit de-emphasis, receive equalization,
on-chip scrambling and DC balancing enables longer distance transmission over lossy cables and backplanes. The
Deserializer automatically locks to incoming data without an
external reference clock or special sync patterns, providing
easy “plug-and-go” operation.
The DS92LV0421 and DS92LV0422 are programmable
though an I2C interface as well as by pins. A built-in ATSPEED BIST feature validates link integrity and may be used
for system diagnostics.
The DS92LV0421 and DS92LV0422 can be used interchangeably with the DS92LV2421 or DS92LV2422. This allows designers the flexibility to connect to the host device and
receiving devices with different interface types, LVDS or LVCMOS.
■ 5-channel (4 data + 1 clock) Channel Link LVDS parallel
■
■
■
■
■
■
■
■
interface supports 24-bit data 3-bit control at 10 – 75 MHz
AC Coupled STP Interconnect up to 10 meters in length
Integrated serial CML terminations
AT–SPEED BIST Mode and status pin
Optional I2C compatible Serial Control Bus
Power Down Mode minimizes power dissipation
1.8V or 3.3V compatible control pin interface
>8 kV ESD (HBM) protection
-40° to +85°C temperature range
SERIALIZER – DS92LV0421
■ Data scrambler for reduced EMI
■ DC–balance encoder for AC coupling
■ Selectable output VOD and adjustable de-emphasis
DESERIALIZER – DS92LV0422
■ Random data lock; no reference clock required
■ Adjustable input receiver equalization
■ EMI minimization on output parallel bus (Spread Spectrum
Clock Generation and LVDS VOD select)
Applications
■
■
■
■
■
Embedded Video and Display
Machine Vision, Industrial Imaging, Medical Imaging
Office Automation — Printers, Scanners, Copiers
Security and Video Surveillance
General purpose data communication
Applications Diagram
30120927
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
© 2010 National Semiconductor Corporation
301209
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DS92LV0421 / DS92LV04225 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel
Interface
PRELIMINARY
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Block Diagrams
30120928
30120972
Ordering Information
NSID
Package Description
Quantity
SPEC
Package ID
DS92LV0421SQE
36–pin LLP, 6.0 X 6.0 X 0.8 mm, 0.5 mm pitch
250
NOPB
SQA36A
DS92LV0421SQ
36–pin LLP, 6.0 X 6.0 X 0.8 mm, 0.5 mm pitch
1000
NOPB
SQA36A
DS92LV0421SQX
36–pin LLP, 6.0 X 6.0 X 0.8 mm, 0.5 mm pitch
2500
NOPB
SQA36A
DS92LV0422SQE
48–pin LLP, 7.0 X 7.0 X 0.8 mm, 0.5 mm pitch
250
NOPB
SQA48A
DS92LV0422SQ
48–pin LLP, 7.0 X 7.0 X 0.8 mm, 0.5 mm pitch
1000
NOPB
SQA48A
DS92LV0422SQX
48–pin LLP, 7.0 X 7.0 X 0.8 mm, 0.5 mm pitch
2500
NOPB
SQA48A
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
DS92LV0421 Pin Diagram
30120919
DS92LV0421 — Top View
DS92LV0421 Pin Descriptions
Pin Name
Pin #
I/O, Type
Description
Channel Link Parallel Input Interface
RxIN[3:0]+
2, 33, 31, 29
I, LVDS
True LVDS Data Input
This pair should have a 100 Ω termination for standard LVDS levels.
RxIN[3:0]-
1, 34, 32, 30,
28
I, LVDS
Inverting LVDS Data Input
This pair should have a 100 Ω termination for standard LVDS levels.
RxCLKIN+
35
I, LVDS
True LVDS Clock Input
This pair should have a 100 Ω termination for standard LVDS levels.
RxCLKIN-
34
I, LVDS
Inverting LVDS Clock Input
This pair should have a 100 Ω termination for standard LVDS levels.
Control and Configuration
PDB
23
I, LVCMOS Power-down Mode Input
w/ pull-down PDB = 1, Device is enabled (normal operation).
Refer to ”Power Up Requirements and PDB Pin” in the Applications Information Section.
PDB = 0, Device is powered down
When the Device is in the power-down state, the driver outputs (DOUT+/-) are both logic
high, the PLL is shutdown, IDD is minimized. Control Registers are RESET.
3
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Pin Name
Pin #
VODSEL
20
De-Emph
19
MAPSEL
26
CONFIG
[1:0]
10, 9
I/O, Type
Description
I, LVCMOS Differential Driver Output Voltage Select — Pin or Register Control
w/ pull-down VODSEL = 1, LVDS VOD is ±450 mV, 900 mVp-p (typ) — Long Cable / De-E Applications
VODSEL = 0, LVDS VOD is ±300 mV, 600 mVp-p (typ)
I, Analog
w/ pull-up
De-Emphasis Control — Pin or Register Control
De-Emph = open (float) - disabled
To enable De-emphasis, tie a resistor from this pin to GND or control via register.
See Table 4
I, LVCMOS Channel Link Map Select — Pin or Register Control
w/ pull-down MAPSEL = 1, MSB on RxIN3+/-. Figure 22
MAPSEL = 0, LSB on RxIN3+/-. Figure 21
I, LVCMOS Operating Modes — Pin or Limited Register Control
w/ pull-down Determines the device operating mode and interfacing device. Table 1
CONFIG[1:0] = 00: Interfacing to DS92LV2422 or DS92LV0422, Control Signal Filter
DISABLED
CONFIG[1:0] = 01: Interfacing to DS92LV2422 or DS92LV0422, Control Signal Filter
ENABLED
CONFIG [1:0] = 10: Interfacing to DS90UR124, DS99R124
CONFIG [1:0] = 11: Interfacing to DS90C124
ID[x]
4
I, Analog
Serial Control Bus Device ID Address Select — Optional
Resistor to Ground and 10 kΩ pull-up to 1.8V rail. See Table 10.
SCL
6
I, LVCMOS
SDA
7
I/O, LVCMOS Serial Control Bus Data Input / Output - Optional
Open Drain SDA requires an external pull-up resistor VDDIO.
BISTEN
21
I, LVCMOS BIST Mode — Optional
w/ pull-down BISTEN = 1, BIST is enabled
BISTEN = 0, BIST is disabled
RES[7:0]
25, 3, 36, 27,
18, 13, 12, 8
Serial Control Bus Clock Input - Optional
SCL requires an external pull-up resistor to VDDIO.
I, LVCMOS Reserved - tie LOW
w/ pull-down
Channel Link II Serial Interface
DOUT+
16
O, CML
True Output.
The output must be AC Coupled with a 0.1 μF capacitor.
DOUT-
15
O, CML
Inverting Output.
The output must be AC Coupled with a 0.1 μF capacitor.
Power and Ground
VDDL
5
Power
Logic Power, 1.8 V ±5%
VDDP
11
Power
PLL Power, 1.8 V ±5%
VDDHS
14
Power
TX High Speed Logic Power, 1.8 V ±5%
VDDTX
17
Power
Output Driver Power, 1.8 V ±5%
VDDRX
24
Power
RX Power, 1.8 V ±5%
VDDIO
22
Power
LVCMOS I/O Power and Channel Link I/O Power 1.8 V ±5% OR 3.3 V ±10%
DAP
Ground
DAP is the large metal contact at the bottom side, located at the center of the LLP
package. Connect to the ground plane (GND) with at least 9 vias.
GND
NOTE: 1= HIGH, 0 L= LOW
The VDD (VDDn and VDDIO) supply ramp should be faster than 1.5 ms with a monotonic rise. If slower then 1.5 ms then a capacitor
on the PDB pin is needed to ensure PDB arrives after all the VDD have settled to the recommended operating voltage.
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
DS92LV0422 Pin Diagram
30120971
DS92LV0422 — Top View
DS92LV0422 Pin Descriptions
Pin Name
Pin #
I/O, Type
Description
Channel Link II Serial Interface
RIN++
40
I, CML
True Input.
The output must be AC Coupled with a 0.1 μF capacitor.
RIN-
41
I, CML
Inverting Input.
The output must be AC Coupled with a 0.1 μF capacitor.
Channel Link Parallel Output Interface
RxIN[3:0]+ 15, 19, 21, 23
O, LVDS
True LVDS Data Output
This pair should have a 100 Ω termination for standard LVDS levels.
RxIN[3:0]-
16, 20, 22, 24
O, LVDS
Inverting LVDS Data Output
This pair should have a 100 Ω termination for standard LVDS levels.
RxCLKIN+
17
O, LVDS
True LVDS Clock Output
This pair should have a 100 Ω termination for standard LVDS levels.
RxCLKIN-
18
O, LVDS
Inverting LVDS Clock Output
This pair should have a 100 Ω termination for standard LVDS levels.
5
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Pin Name
Pin #
I/O, Type
Description
LVCMOS Outputs
LOCK
27
O, LVCMOS LOCK Status Output
LOCK = 1, PLL is locked, output stated determined by OEN.
LOCK = 0, PLL is unlocked, output states determined by OSS_SEL and OEN.
See Table 5.
Control and Configuration
PDB
1
I, LVCMOS Power-down Mode Input
w/ pull-down PDB = 1, Device is enabled (normal operation).
Refer to ”Power Up Requirements and PDB Pin” in the Applications Information Section.
PDB = 0, Device is powered down
When the Device is in the power-down state, the driver outputs (DOUT+/-) are both logic
high, the PLL is shutdown, IDD is minimized. Control Registers are RESET.
VODSEL
33
I, LVCMOS Parallel LVDS Driver Output Voltage Select — Pin or Register Control
w/ pull-down VODSEL = 1, LVDS VOD is ±450 mV, 900 mVp-p (typ) — Long Cable / De-E Applications
VODSEL = 0, LVDS VOD is ±300 mV, 600 mVp-p (typ)
OEN
30
I, LVCMOS Output Enable.
w/ pull-down See Table 5.
OSS_SEL
35
I, LVCMOS Output Sleep State Select Input.
w/ pull-down See Table 5.
LFMODE
36
I, LVCMOS SSCG Low Frequency Mode — Pin or Register Control
w/ pull-down LF_MODE = 1, low frequency mode (TxCLKOUT = 10–20 MHz)
LF_MODE = 0, high frequency mode (TxCLKOUT = 20–65 MHz)
SSCG not avaialble above 65 MHz.
MAPSEL
34
I, LVCMOS Channel Link Map Select — Pin or Register Control
w/ pull-down MAPSEL = 1, MSB on TxOUT3+/-.
MAPSEL = 0, LSB on TxOUT3+/-.
CONFIG
[1:0]
11, 10
I, LVCMOS Operating Modes — Pin or Limited Register Control
w/ pull-down Determine the device operating mode and interfacing device.
CONFIG[1:0] = 00: Interfacing to DS92LV2421 or DS92LV0421, Control Signal Filter
DISABLED
CONFIG[1:0] = 01: Interfacing to DS92LV2421 or DS92LV0421, Control Signal Filter
ENABLED
CONFIG [1:0] = 10: Interfacing to DS90UR241, DS99R421
CONFIG [1:0] = 11: Interfacing to DS90C124
SSC[2:0]
7, 2, 3
I, LVCMOS Spread Spectrum Clock Generation (SSCG) Range Select
w/ pull-down See Table 8 Table 9
RES
37
I, LVCMOS Reserved
w/ pull-down
Control and Configuration — STRAP PIN
EQ
28 [PASS]
STRAP
EQ Gain Control of Channel Link II Serial Input
I, LVCMOS EQ = 1, EQ gain is enabled (~13 dB)
w/ pull-down EQ = 0, EQ gain is disabled (~1.625 dB)
Optional BIST Mode
BISTEN
PASS
29
28
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I, LVCMOS BIST Mode — Optional
w/ pull-down BISTEN = 1, BIST is enabled
BISTEN = 0, BIST is disabled
O, LVCMOS
PASS Output (BIST Mode) — Optional
PASS =1, no errors detected
PASS = 0, errors detected
Leave open if unused. Route to a test point (pad) recommended.
6
Pin #
I/O, Type
Description
Serial Control Bus Device ID Address Select — Optional
Resistor to Ground and 10 kΩ pull-up to 1.8V rail. See .
Optional Serial Bus Control
ID[x]
12
I, Analog
SCL
5
I, LVCMOS
Open Drain
SDA
4
Serial Control Bus Clock Input - Optional
SCL requires an external pull-up resistor to 3.3V.
I/O, LVCMOS Serial Control Bus Data Input / Output - Optional
Open Drain SDA requires an external pull-up resistor 3.3V.
Power and Ground
VDDL
6, 31
Power
Logic Power, 1.8 V ±5%
VDDA
38, 43
Power
Analog Power, 1.8 V ±5%
VDDP
6
Power
PLL Power, 1.8 V ±5%
VDDSC
46, 47
Power
SSC Generator Power, 1.8 V ±5%
VDDTX
24
Power
Channel Link LVDS Parallel Output Power, 1.8 V ±5%
VDDIO
25
Power
LVCMOS I/O Power and Channel Link I/O Power 1.8 V ±5% OR 3.3 V ±10%
GND
9, 14, 26, 32,
39, 44, 45, 48
Ground
Ground
DAP
DAP
Ground
DAP is the large metal contact at the bottom side, located at the center of the LLP
package. Connect to the ground plane (GND) with at least 9 vias.
NOTE: 1= HIGH, 0 L= LOW
The VDD (VDDn and VDDIO) supply ramp should be faster than 1.5 ms with a monotonic rise. If slower then 1.5 ms then a capacitor
on the PDB pin is needed to ensure PDB arrives after all the VDD have settled to the recommended operating voltage.
7
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Pin Name
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Air Discharge
(RIN+, RIN-)
Contact Discharge
(RIN+, RIN-)
ESD Rating (HBM)
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage – VDDn (1.8V)
Supply Voltage – VDDIO
Supply Voltage – VDDTX (3.3V)
LVCMOS I/O Voltage
LVDS Input Voltage
LVDS Output Voltage
CML Driver Output Voltage
Receiver Input Voltage
Junction Temperature
Storage Temperature
36L LLP Package
Maximum Power Dissipation
Capacity at 25°C
Derate above 25°C
−0.3V to +2.5V
−0.3V to +4.0V
−0.3V to +4.0V
−0.3V to +(VDDIO + 0.3V)
−0.3V to (VDDIO + 0.3V)
−0.3V to (VDDTX + 0.3V)
−0.3V to (– VDDn + 0.3V)
−0.3V to (VDD + 0.3V)
+150°C
−65°C to +150°C
θJC
48L LLP Package
Maximum Power Dissipation
Capacity at 25°C
Derate above 25°C
For soldering specifications:
See product folder at www.national.com and
www.national.com/ms/MS/MS-SOLDERING.pdf
Recommended Operating
Conditions
Supply Voltage (VDDn)
Supply Voltage (VDDTX)
LVCMOS Supply
Voltage (VDDIO)
OR
LVCMOS Supply
Voltage (VDDIO)
Operating Free Air
Temperature (TA)
RxCLKIN/TxCLKOUT
Clock Frequency
Supply Noise (Note 10)
1/ θJA°C/W
27.7 °C/W
θJC
ESD Rating (IEC, powered-up
only), RD = 330Ω, CS = 150 pF
≥±1.25 kV
≥±250 V
ESD Rating (MM)
4.5 °C/W
θJA
≥±8 kV
≥±8 kV
ESD Rating (CDM)
1/ θJA°C/W
27.4 °C/W
θJA
≥±30 kV
Min
1.71
3.0
1.71
Nom
1.8
3.3
1.8
Max
1.89
3.6
1.89
Units
V
V
V
3.0
3.3
3.6
V
−40
10
+25
+85
75
°C
MHz
100
mVP-P
3.0 °C/W
DC Electrical Characteristics
Over recommended operating supply and temperature ranges unless otherwise specified. (Note 2, Note 3, Note 4)
Symbol
Parameter
Conditions
Pin/Freq.
Min
Typ
Max
Units
2.0
VDDIO
V
0.65*
VDDIO
VDDIO
V
GND
0.8
V
GND
0.35*
VDDIO
V
DS92LV0421 LVCMOS INPUT DC SPECIFICATIONS
VDDIO = 3.0 to 3.6V
VIH
High Level Input Voltage
VDDIO = 1.71 to 1.89V
VDDIO = 3.0 to 3.6V
VIL
IIN
Low Level Input Voltage
Input Current
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VDDIO = 1.71 to 1.89V
VDDIO = 3.0
to 3.6V
VIN = 0V or VDDIO
VDDIO = 1.7
to 1.89V
8
PDB,
VODSEL,
MAPSEL,
CONFIG[1:0],
BISTEN
−15
±1
+15
μA
−15
±1
+15
μA
Parameter
Conditions
Pin/Freq.
Min
Typ
Max
Units
2.0
VDDIO
V
0.65*
VDDIO
VDDIO
V
GND
0.8
V
GND
0.35*
VDDIO
V
DS92LV0422 LVCMOS I/O DC SPECIFICATIONS
VDDIO = 3.0 to 3.6V
VIH
High Level Input Voltage
VDDIO = 1.71 to 1.89V
VDDIO = 3.0 to 3.6V
VIL
IIN
Low Level Input Voltage
Input Current
VDDIO = 1.71 to 1.89V
VIN = 0V or VDDIO
VOH
High Level Output Voltage
IOH = -0.5 mA
VOL
Low Level Output Voltage
IOL = +0.5 mA
IOS
IOZ
Output Short Circuit Current
TRI-STATE® Output Current
VDDIO = 3.0
to 3.6V
PDB,
VODSEL,
OEN,
MAPSEL,
LFMODE,
SSC[2:0],
BISTEN
VDDIO = 1.7
to 1.89V
−15
±1
+15
μA
−15
±1
+15
μA
VDDIO –
0.2
VDDIO
GND
VDDIO = 3.0 to
LOCK,
3.6 V
PASS
VDDIO = 1.71
to 1.89V
VOUT = 0V
VDDIO = 3.0 to
PDB = 0V, OSS_SEL
3.6 V
= 0V, VOUT = 0V or
VDDIO = 1.71
VDDIO
to 1.89V
V
0.2
V
-10
mA
-3
-10
+10
-15
+15
μA
DS92LV0421 CHANNEL LINK PARALLEL LVDS RECEIVER DC SPECIFICATIONS
VTH
Differential Threshold High
Voltage
VTL
Differential Threshold Low
Voltage
|VID|
Differential Input Voltage
Swing
VCM
Common Mode Voltage
IIN
Input Current
+100
mV
VCM = 1.2V, Figure 1
−100
RxIN[3:0]+/-,
RxCLKIN+/-,
200
600
mV
VDDIO = 3.3V
0
1.2
2.4
VDDIO = 1.8V
0
1.2
1.7
−10
±1
+10
μA
VODSEL = L
100
250
400
mV
VODSEL = H
200
400
600
V
DS92LV0422 CHANNEL LINK PARALLEL LVDS DRIVER DC SPECIFICATIONS
|VOD|
Differential Output Voltage
VODp-p
Differential Output Voltage A –
B
ΔVOD
Output Voltage Unbalance
VOS
Offset Voltage
ΔVOS
Offset Voltage Unbalance
IOS
Output Short Circuit Current
IOZ
Output TRI-STATE® Current
RL = 100Ω
500
mVp-p
VODSEL = H RxCLKOUT
+,
TxCLKOUT-,
VODSEL = L
TxOUT[3:0]+,
VODSEL = H TxOUT[3:0]-
800
mVp-p
1.0
1
50
mV
1.2
1.5
V
50
mV
1.2
1
V
-5
-10
9
mV
VODSEL = L
mA
+10
μA
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Symbol
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Symbol
Parameter
Conditions
Pin/Freq.
Min
Typ
Max
VODSEL = 0
±225
±300
±375
VODSEL = 1
±350
±450
±550
Units
DS92LV0421 Channel Link II CML DRIVER DC SPECIFICATIONS
VOD
Differential Output Voltage
VODp-p
Differential Output Voltage
(DOUT+) – (DOUT-)
RL = 100Ω,
De-emph = disabled,
Figure 3
mV
VODSEL = 0
600
mVp-p
VODSEL = 1
900
mVp-p
RL = 100Ω, De-emph = disabled,
VODSEL = L
ΔVOD
Output Voltage Unbalance
VOS
Offset Voltage – Single-ended RL = 100Ω,
At TP A & B, Figure 2
De-emph = disabled
ΔVOS
Offset Voltage Unbalance
Single-ended
At TP A & B, Figure 2
RL = 100Ω, De-emph = disabled
IOS
Output Short Circuit Current
DOUT+/- = 0V,
De-emph = disabled
RT
Internal Termination Resistor
1
VODSEL = 0 DOUT+,
VODSEL = 1 DOUT-
VODSEL = 0
TBD
mV
1.65
V
1.575
V
1
mV
−36
mA
80
120
Ω
+50
mV
DS92LV0422 CHANNEL LINK II CML RECEIVER DC SPECIFICATIONS
VTH
Differential Input Threshold
High Voltage
VTL
Differential Input Threshold
Low Voltage
VCM
Common mode Voltage,
Internal VBIAS
RT
Input Termination
VCM = +1.2V (Internal VBIAS)
RIN+,
RIN-
-50
mV
1.2
85
V
100
115
Ω
65
TBD
mA
TBD
TBD
mA
TBD
TBD
mA
TBD
TBD
mA
TBD
TBD
mA
TBD
TBD
mA
DS92LV0421 SUPPLY CURRENT
IDDT1
IDDIOT1
IDDT2
IDDIOT2
Supply Current
(includes load current)
RL = 100Ω, f = 65MHz
IDDT3
Checker Board
Pattern,
De-emph = disabled,
VODSEL = H, Figure
16
VDD= 1.89V
Checker Board
Pattern,
De-emph = disabled,
VODSEL = L, Figure
16
VDD= 1.89V
RANDOM pattern,
De-emph = disabled,
VODSEL = H
IDDIOT3
IDDZ
IDDIOZ
VDDIO=
1.89V
VDDIO
VDDIO = 3.6V
VDDIO=
1.89V
All VDD pins
VDDIO
VDDIO = 3.6V
VDD= 1.89V
All VDD pins
VDDIO=
1.89V
VDDIO
VDDIO = 3.6V
VDD= 1.89V
Supply Current Power-down
All VDD pins
All VDD pins
TBD
mA
TBD
mA
TBD
mA
100
TBD
µA
TBD
TBD
µA
TBD
TBD
µA
TBD
TBD
mA
VDDTX = 3.6 V VDDTX
TBD
TBD
mA
VDDIO = 1.89 VDDIO
V
TBD
TBD
mA
VDDIO = 3.6 V
TBD
TBD
mA
PDB = 0V , (All other VDDIO=
LVCMOS Inputs = 0V) 1.89V
VDDIO
VDDIO = 3.6V
DS92LV0422 SUPPLY CURRENT
IDD1
IDDTX1
Supply Current
(Includes load current)
75 MHz Clock
IDDIO1
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Checker Board
Pattern,
VODSEL = H,
SSCG = On
VDDn = 1.89
V
10
All VDD(1:8)
pins
IDDZ
Parameter
Supply Current Power Down
IDDTXZ
Conditions
PDB = 0V,
All other LVCMOS
Inputs = 0V
IDDIOZ
Pin/Freq.
Min
Typ
Max
Units
VDD = 1.89 V All VDD(1:8)
pins
TBD
TBD
mA
VDDTX = 3.6 V VDDTX
TBD
TBD
mA
VDDIO = 1.89 VDDIO
V
TBD
TBD
mA
VDDIO = 3.6V
TBD
TBD
mA
Min
Typ
Max
Units
Switching Characteristics
Over recommended operating supply and temperature ranges unless otherwise specified.
Symbol
Parameter
Conditions
DS92LV0421 CHANNEL LINK PARALLEL LVDS INPUT
tRSP0
Receiver Strobe Position-bit 0
TBD
1.1
TBD
ns
tRSP1
Receiver Strobe Position-bit 1
TBD
3.3
TBD
ns
tRSP2
Receiver Strobe Position-bit 2
TBD
5.5
TBD
ns
tRSP3
Receiver Strobe Position-bit 3
TBD
7.7
TBD
ns
tRSP4
Receiver Strobe Position-bit 4
TBD
9.9
TBD
ns
tRSP5
Receiver Strobe Position-bit 5
TBD
12.1
TBD
ns
tRSP6
Receiver Strobe Position-bit 6
TBD
14.3
TBD
ns
RJIT
RxCLKIN Cycle-to-Cycle Jitter
(Input clock requirement)
TBD
ns
0.6
ns
RxCLKIN = 75 MHz,
RxIN[3:0]
Figure 5
DS92LV0422 CHANNEL LINK PARALLEL LVDS OUTPUT
tLHT
Low to High Transition Time
tTHLT
High to Low Transition Time
tDCCJ
Cycle-to-Cycle Output Jitter
tTTP1
Transmitter Pulse Position for
bit 1
tTTP0
RL = 100Ω
0.3
0.3
0.6
ns
TxCLKOUT± = 10 MHz
900
2100
ps
TxCLKOUT± = 75MHz
75
125
ps
10 – 75 MHz
0
UI
Transmitter Pulse Position for
bit 0
1
UI
tTTP6
Transmitter Pulse Position for
bit 6
2
UI
tTTP5
Transmitter Pulse Position for
bit 5
3
UI
tTTP4
Transmitter Pulse Position for
bit 4
4
UI
tTTP3
Transmitter Pulse Position for
bit 3
5
UI
tTTP2
Transmitter Pulse Position for
bit 2
6
UI
tSD
Delay-Latency
tTPDD
Power Down Delay
Active to OFF
75 MHz
tTXZR
Enable Delay
OFF to Active
75 MHz
TBD
TBD
ns
6
10
ns
40
55
ns
DS92LV0421 Channel Link II CML OUTPUT
tHLT
Output Low-to-High Transition
Time
Figure 3
RL = 100Ω, De-emphasis = disabled,
VODSEL = 0
100
200
300
ps
RL = 100Ω, De-emphasis = disabled,
VODSEL = 1
100
200
300
ps
11
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Symbol
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Symbol
tHLT
Parameter
Output High-to-Low Transition
Time
Figure 4
Conditions
Min
Typ
Max
Units
RL = 100Ω, De-emphasis = disabled,
VODSEL = 0
130
260
390
ps
RL = 100Ω, De-emphasis = disabled,
VODSEL = 1
100
200
300
ps
TBD
TBD
ns
10
ms
140*T
TBD
ns
0.3
TBD
UI
tXZD
Ouput Active to OFF Delay,
Figure 9
tPLD
PLL Lock Time, Figure 7
RL = 100Ω
tSD
Delay - Latency, Figure 10
RL = 100Ω
tDJIT
Output Total Jitter,
Figure 12
RL = 100Ω, De-Emph = disabled,
RANDOM pattern
λSTXBW
Jitter Transfer
Function -3 dB Bandwidth
TBD
kHz
δSTX
Jitter Transfer
Function Peaking
TBD
dB
SSCG = OFF,
10 MHz
TBD
ms
SSCG = ON,
10 MHz
TBD
ms
SSCG = OFF,
75 MHz
TBD
ms
SSCG = ON,
75 MHz
TBD
ms
EQ = OFF
Jitter Frequency > 10 MHz
>0.45
UI
DS92LV0422 CHANNEL LINK II CML INPUT
tDDLT
tDJIT
Lock Time
Input Jitter Tolerance
DS92LV0422 LVCMOS OUTPUTS
tCLH
Low to High Transition Time
10
15
ns
High to Low Transition Time
CL = 8 pF
LOCK pin,
PASS pin
tCHL
10
15
ns
tPASS
BIST PASS Valid Time,
BISTEN = 1
PASS pin
10 MHz
560
570
ns
75 MHz
70
75
ns
DS92LV0422 SSCG MODE
tDEV
Spread Spectrum Clocking
Deviation Frequency
TxCLKOUT = 10 – 65 MHz,
SSC[2:0] = ON
±0.5
±2
%
tMOD
Spread Spectrum Clocking
Modulation Frequency
TxCLKOUT = 10 – 65 MHz,
SSC[2:0] = ON
8
100
kHz
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12
Over recommended operating supply and temperature ranges unless otherwise specified.
Symbol
Parameter
Conditions
VIH
Input High Level
SDA and SCL
VIL
Input Low Level Voltage
SDA and SCL
VHY
Input Hysteresis
Max
Units
0.7*
VDDIO
Min
Typ
VDDIO
V
GND
0.3*
VDDIO
V
>50
mV
VOL
SDA, IOL = 3mA
0
0.36
V
Iin
SDA or SCL, Vin = VDDIO or GND
-10
+10
µA
SDA, RPU = X, Cb ≤ 400pF, Figure 18
TBD
TBD
ns
TBD
TBD
ns
tR
SDA RiseTime – READ
tF
SDA Fall Time – READ
tSU;DAT
Set Up Time — READ
Figure 18
TBD
ns
tHD;DAT
Hold Up Time — READ
Figure 18
TBD
ns
tSP
Input Filter
Cin
Input Capacitance
SDA or SCL
50
ns
<5
pF
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability
and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in
the Recommended Operating Conditions is not implied. The Recommended Operating Conditions indicate conditions at which the device is functional and the
device should not be operated beyond such conditions.
Note 2: The Electrical Characteristics tables list guaranteed specifications under the listed Recommended Operating Conditions except as otherwise modified
or specified by the Electrical Characteristics Conditions and/or Notes. Typical specifications are estimations only and are not guaranteed.
Note 3: Typical values represent most likely parametric norms at VDD = 3.3V, Ta = +25 degC, and at the Recommended Operation Conditions at the time of
product characterization and are not guaranteed.
Note 4: Current into device pins is defined as positive. Current out of a device pin is defined as negative. Voltages are referenced to ground except VOD, ΔVOD,
VTH and VTL which are differential voltages.
Note 5: When the device output is at TRI-STATE the Deserializer will lose PLL lock. Resynchronization / Relock must occur before data transfer require tPLD
Note 6: tPLD is the time required by the device to obtain lock when exiting power-down state with an active RxCLKIN.
Note 7: UI – Unit Interval is equivalent to one serialized data bit width (1UI = 1 / 28*PCLK). The UI scales with PCLK frequency.
Note 8: tDPJ is the maximum amount the period is allowed to deviate over many samples.
Note 9: tDCCJ is the maximum amount of jitter between adjacent clock cycles.
Note 10: Supply noise testing was done with minimum capacitors on the PCB. A sinusoidal signal is AC coupled to the VDDn (1.8V) supply with amplitude = 100
mVp-p measured at the device VDDn pins. Bit error rate testing of input to the Ser and output of the Des with 10 meter cable shows no error when the noise
frequency on the Ser is less than 750 kHz. The Des on the other hand shows no error when the noise frequency is less than 400 kHz.
Note 11: Specification is guaranteed by characterization and is not tested in production.
Note 12: Specification is guaranteed by design and is not tested in production.
13
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
DC and AC Serial Control Bus Characteristics
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
AC Timing Diagrams and Test Circuits
30120962
FIGURE 1. Channel Link DC VTH/VTL Definition
30120946
FIGURE 2. Output Test Circuit
30120930
FIGURE 3. Output Waveforms
30120947
FIGURE 4. Output Transition Times
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14
FIGURE 5. DS92LV0421 Channel Link Receiver Strobe Positions
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15
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120961
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120970
FIGURE 6. DS92LV0422 LVDS Transmitter Pulse Positions
30120948
FIGURE 7. DS92LV0421 Lock Time
30120968
FIGURE 8. DS92LV0422 Lock Time
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16
FIGURE 9. DS92LV0421 Disable Time
30120910
FIGURE 10. DS92LV0421 Latency Delay
30120967
FIGURE 11. DS92LV0422 Latency Delay
17
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120949
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120950
FIGURE 12. DS92LV0421 Output Jitter
30120975
FIGURE 13. DS92LV0422 Output State Diagram
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18
FIGURE 14. DS92LV0422 Power Down Delay
30120980
FIGURE 15. DS92LV0422 Enable Delay
30120932
FIGURE 16. Checkerboard Data Pattern
19
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120979
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120952
FIGURE 17. BIST PASS Waveform
30120936
FIGURE 18. Serial Control Bus Timing Diagram
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20
The DS92LV0421 / DS92LV0422 chipset transmits and receives 24-bits of data and 3 control signals, formatted as
Channel Link LVDS data, over a single serial CML pair operating at 280 Mbps to 2.1 Gbps serial line rate. The serial
stream contains an embedded clock, video control signals
and is DC-balance to enhance signal quality and supports AC
coupling.
The Des can attain lock to a data stream without the use of a
separate reference clock source, which simplifies system
complexity and overall cost. The Des also synchronizes to the
Ser regardless of the data pattern, delivering true automatic
“plug and lock” performance. It can lock to the incoming serial
stream without the need of special training patterns or sync
characters. The Des recovers the clock and data by extracting
the embedded clock information, validating and then deserializing the incoming data stream providing a parallel Channel
Link LVDS bus to the display, ASIC, or FPGA.
The DS92LV0421 / DS92LV0422 chipset can operate with up
to 24 bits of raw data with three slower speed control bits encoded within the serial data stream. For applications that
require less the maximum 24 pclk speed bit spaces, the user
will need to ensure that all unused bit spaces or parallel LVDS
channels are set to valid logic states, as all parallel lanes and
27 bit spaces will always be sampled.
Block Diagrams for the chipset are shown at the beginning of
this datasheet.
TABLE 1. DS92LV0421 Configuration Modes
CON
FIG1
CON Mode
FIG0
Des Device
L
L
Normal Mode, Control
Signal Filter disabled
DS92LV0422,
DS92LV2422
L
H
Normal Mode, Control
Signal Filter enabled
DS92LV0422,
DS92LV2422
H
L
Backwards Compatible
DS90UR124,
DS99R124
H
H
Backwards Compatible
DS90C124
TABLE 2. DS92LV0422 Configuration Modes
CON
FIG1
Parallel LVDS Data Transfer
The DS92LV0421/DS92LV0422 can be configured to accept/
transmit 24-bit data with 2 different mapping schemes: The
normal Channel Link LVDS format (MSBs on LVDS channel
3) can be selected by configuring the MAPSEL pin to HIGH.
See Figure 13 for the normal Channel Link LVDS mapping.
An alternate mapping scheme is available (LSBs on LVDS
channel 3) by configuring the MAPSEL pin to LOW. See Figure 14 for the alternate LVDS mapping. The mapping
schemes can also be selected by register control.
The alternate mapping scheme is useful in some applications
where the receiving system, typically a display, requires that
the LSBs for the 24-bit color data be sent on LVDS channel
3.
CON Mode
FIG0
Des Device
L
L
Normal Mode, Control
Signal Filter disabled
DS92LV0421,
DS92LV2421
L
H
Normal Mode, Control
Signal Filter enabled
DS92LV0421,
DS92LV2421
H
L
Backwards Compatible
DS90UR241,
DS99R421
H
H
Backwards Compatible
DS90C241
Video Control Signal Filter
The three control bits can be used to communicate any low
speed signal. The most common use for these bits is in the
display or machine vision applications. In a display application
these bits are typically assigned as: Bit 26 – DE, Bit 24 – HS,
Bit 25 – VS. In the machine vision standard, Camera Link,
these bits are typically assigned: Bit 26 – DVAL, Bit 24 –
LVAL, Bit 25 – FVAL.
When operating the devices in Normal Mode, the Video Control Signals (DE, HS, VS) have the following restrictions:
• Normal Mode with Control Signal Filter Enabled:
DE and HS — Only 2 transitions per 130 clock cycles are
transmitted, the transition pulse must be 3 PCLK or longer.
• Normal Mode with Control Signal Filter Disabled:
DE and HS — Only 2 transitions per 130 clock cycles are
transmitted, no restriction on minimum transition pulse.
• VS — Only 1 transition per 130 clock cycles are
transmitted, minimum pulse width is 130 clock cycles.
Video Control Signals are defined as low frequency signals
with limited transitions. Glitches of a control signal can cause
a visual display error. This feature allows for the chipset to
validate and filter out any high frequency noise on the control
signals. See Figure 20.
Serial Data Transfer
The DS92LV0421 transmits a pixel of data in the following
format: C1 and C0 represent the embedded clock in the serial
stream. C1 is always HIGH and C0 is always LOW. b[23:0]
contain the scrambled RGB data. DCB is the DC-Balanced
control bit. DCB is used to minimize the short and long-term
DC bias on the signal lines. This bit determines if the data is
unmodified or inverted. DCA is used to validate data integrity
in the embedded data stream and can also contain encoded
control (VS,HS,DE). Both DCA and DCB coding schemes are
generated by the DS92LV0421 and decoded by the paring
deserializer automatically. Figure 19 illustrates the serial
stream per PCLK cycle.
30120937
FIGURE 19. Channel Link II Serial Stream
21
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
OPERATING MODES AND BACKWARD COMPATIBILITY
(CONFIG[1:0])
The DS92LV0421 and DS92LV0422 are backward compatible with previous generations of National Ser/Des. Configuration modes are provided for backwards compatibility with
the DS90C241/DS90C124 and also the DS90UR241/
DS90UR124 and DS99R241/DS99R124 by setting the respective mode with the CONFIG[1:0] pins as shown in Table
1 and Table 2. The selection also determine whether the
Video Control Signal filter feature is enabled or disabled in
Normal mode. Backward compatibility modes are selectable
through the control pins only. The Control Signal Filter can be
selected by pin or through register programming.
Functional Description
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
BIT MAPPING SELECT
The DS92LV0421 and DS92LV0422 can be configured to accept the LVDS parallel data with 2 different mapping
schemes: LSBs on RxIN[3] shown in Figure 21 or MSBs on
RxIN[3] shown in Figure 22. The user selects which mapping
scheme is controlled by MAPSEL pin or by Register.
30120942
FIGURE 20. Video Control Signal Filter Wavefrom
30120965
FIGURE 21. 8–bit Channel Link Mapping: LSB's on RxIN3
30120966
FIGURE 22. 8–bit Channel Link Mapping: MSB's on RxIN3
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22
Ser — De-Emphasis (De-Emph)
The De-Emph pin controls the amount of de-emphasis beginning one full bit time after a logic transition that the device
drives. This is useful to counteract loading effects of long or
lossy cables. This pin should be left open for standard switching currents (no de-emphasis) or if controlled by register. Deemphasis is selected by connecting a resistor on this pin to
ground, with R value between 0.5 kΩ to 1 MΩ, or by register
setting. When using De-Emphasis it is recommended to set
VODSEL = H.
EMI Reduction Features
TABLE 4. De-Emphasis Resistor Value
Resistor Value (kΩ)
De-Emphasis Setting
Open
Disabled
0.6
- 12 dB
1.0
- 9 dB
2.0
- 6 dB
5.0
- 3 dB
Data Randomization & Scrambling
Channel Link II Ser / Des feature a 3 step encoding process
which enables the use of AC coupled interconnects and also
helps to manage EMI. The serializer first passes the parallel
data through a scrambler which randomizes the data. The
randomized data is then DC balanced. The DC balanced and
randomized data then goes through a bit shuffling circuit and
is transmitted out on the serial line. This encoding process
helps to prevent static data patterns on the serial stream. The
resulting frequency content of the serial stream ranges from
the parallel clock frequency to the nyquist rate. For example,
if the Ser / Des chip set is operating at a parallel clock frequency of 50 MHz, the resulting frequency content of serial
stream ranges from 50 MHz to 700 MHz ( 50 MHz *28 bits =
1.4 Gbps / 2 = 700 MHz ).
Ser — Spread Spectrum Compatibility
The RxCLKIN of the Channel Link input is capable of tracking
spread spectrum clocking (SSC) from a host source. The RxCLKIN will accept spread spectrum tracking up to 35kHz
modulation and ±0.5, ±1 or ±2% deviations (center spread).
The maximum conditions for the RxCLKIN input are: a modulation frequency of 35kHz and amplitude deviations of ±2%
(4% total).
30120960
FIGURE 23. De-Emph vs. R value
Power Saving Features
Ser — Power Down Feature (PDB)
The DS92LV0421 has a PDB input pin to ENABLE or POWER
DOWN the device. This pin is controlled by the host and is
used to save power, disabling the link when the display is not
needed. In the POWER DOWN mode, the high-speed driver
outputs are both pulled to VDD and present a 0V VOD state.
Note – in POWER DOWN, the optional Serial Bus Control
Registers are RESET.
Ser — Integrated Signal Conditioning Features
Ser — VOD Select (VODSEL)
The DS92LV0421 differential output voltage may be increased by setting the VODSEL pin High. When VODSEL is
Low, the DC VOD is at the standard (default) level. When
VODSEL is High, the DC VOD is increased in level. The increased VOD is useful in extremely high noise environments
and also on extra long cable length applications. When using
de-emphasis it is recommended to set VODSEL = H to avoid
excessive signal attenuation especially with the larger deemphasis settings. This feature may be controlled by the
external pin or by register.
Ser — Stop Clock Feature
The DS92LV0421 will enter a low power SLEEP state when
the RxCLKIN is stopped. A STOP condition is detected when
the input clock frequency is less than 3 MHz. The clock should
be held at a static Low or high state. When the RxCLKIN starts
again, the device will then lock to the valid input RxCLKIN and
then transmits the RGB data to the desializer. Note – in STOP
CLOCK SLEEP, the optional Serial Bus Control Registers
values are RETAINED.
TABLE 3. Ser — Differential Output Voltage
Input
Effect
VODSEL
VOD
mV
VOD
mVp-p
H
±420
840
L
±280
560
1.8V or 3.3V VDDIO Operation
The DS92LV0421 parallel control bus can operate with 1.8 V
or 3.3 V levels (VDDIO) for host compatibility. The 1.8 V levels
will offer a system power savings.
23
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
SERIALIZER Functional Description
The Ser converts a Channel Link LVDS clock and data bus to
a single serial output data stream, and also acts as a signal
generator for the chipset Built In Self Test (BIST) mode. The
device can be configured via external pins or through the optional serial control bus. The Ser features enhanced signal
quality on the link by supporting: a selectable VOD level, a
selectable de-emphasis signal conditioning and also the
Channel Link II data coding that provides randomization,
scrambling, and DC Balanacing of the data. The Ser includes
multiple features to reduce EMI associated with display data
transmission. This includes the randomization and scrambling of the serial data and also the system spread spectrum
clock support. The Ser features power saving features with a
sleep mode, auto stop clock feature, and optional 1.8 V or
3.3V I/O compatibility.
See also the Functional Description of the chipset's serial
control bus and BIST modes.
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Optional Serial Bus Control
Please see the following section on the optional Serial Bus
Control Interface.
Oscillator Output — Optional
The DS92LV0422 provides an optional TxCLKOUT when the
input clock (serial stream) has been lost. This is based on an
internal oscillator. The frequency of the oscillator may be selected. This feature may be controlled by the external pin or
through the registers.
Optional BIST Mode
Please see the following section on the chipset BIST mode
for details.
CLOCK-DATA RECOVERY STATUS FLAC (LOCK),
OUTPUT ENABLE (OEN) AND OUTPUT STATE SELECT
()SS_SEL)
When PDB is driven HIGH, the CDR PLL begins locking to
the serial input, LOCK is LOW and the Channel Link interface
state is determined by the state of the OSS_SEL pin.
After the DS92LV0422 completes its lock sequence to the input serial data, the LOCK output is driven HIGH, indicating
valid data and clock recovered from the serial input is available on the Channel Link outputs. The TxCLKOUT output is
held at its current state at the change from OSC_CLK (if this
is enabled via OSC_SEL) to the recovered clock (or vice versa). Note that the Channel Link outputs may be held in an
inactive state (TRI-STATE®) through the use of the Output
Enable pin (OEN).
If there is a loss of clock from the input serial stream, LOCK
is driven LOW and the state of the outputs are based on the
OSS_SEL setting (configuration pin or register).
DESERIALIZER Functional
Description
The Des converts a single input serial data stream to a wide
parallel output bus, and also provides a signal check for the
chipset Built In Self Test (BIST) mode. The device can be
configured via external pins and strap pins or through the optional serial control bus. The Des features enhance signal
quality on the link with an integrated equalizer on the serial
input and Channel Link II data encoding which provides randomization, scrambling, and DC balanacing of the data. The
Des includes multiple features to reduce EMI associated with
data transmission. This includes the randomization and
scrambling of the data, the output spread spectrum clock
generation (SSCG) support and output clock and data slew
rate select. The Des features power saving features with a
power down mode, and optional LVCMOS (1.8 V) interface
compatibility.
TABLE 5. Des Output State Table
INPUTS
OUTPUTS
PDB
OEN
OSS_SEL
LOCK
OTHER OUTPUTS
L
X
X
X
TxCLKOUT is TRI-STATE®
TxOUT[3:0] are TRI-STATE®
PASS is TRI-STATE®
L
X
L
L
TxCLKOUT is TRI-STATE®
TxOUT[3:0] are TRI-STATE®
PASS is HIGH
H
L
H
L
TxCLKOUT is TRI-STATE®
TxOUT[3:0] are TRI-STATE®
PASS is TRI-STATE®
H
H
H
L
TxCLKOUT is TRI-STATE® or OSC Output through Register bit
TxOUT[3:0] are TRI-STATE®
PASS is TRI-STATE®
H
L
X
H
TxCLKOUT is TRI-STATE®
TxOUT[3:0] are TRI-STATE®
PASS is HIGH
H
H
X
H
TxCLKOUT is Active
TxOUT[3:0] are Active
PASS is Active
(Normal operating mode)
Des — Integrated Signal Conditioning Features — Des
Des — Input Equalizer Gain (EQ)
The Des can enable receiver input equalization of the serial
stream to increase the eye opening to the Des input. Note this
function cannot be seen at the RxIN+/- input. The equalization
feature may be controlled by the external pin or by register.
Des — Common Mode Filter Pin (CMF) — Optional
The Des provides access to the center tap of the internal termination. A capacitor may be placed on this pin for additional
common-mode filtering of the differential pair. This can be
useful in high noise environments for additional noise rejection capability. A 0.1μF capacitor may be connected to this
pin to Ground.
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TABLE 6. Receiver Equalization
Configuration Table
24
EQ (Strap Option)
Effect
L
OFF, ~1.625 dB
H
~13 dB
Des — VOD Select (VODSEL)
The differential output voltage of teh Channel Link interface
is controlled by the VODSEL input.
TABLE 7. Des — Differential Output
Voltage Table
VODSEL
Result
L
VOD is 250 mV TYP (500 mVp-p)
H
VOD is 400 mV TYP (800 mVp-p)
TABLE 8. SSCG Configuration (LF_MODE = L) — Des Output
SSC[3:0] Inputs
LF_MODE = L (20 — 65 MHz)
Result
SSC3
SSC2
SSC1
SSC0
fdev (%)
fmod (kHz)
L
L
L
L
N/A
CLK/2168
L
L
L
H
±0.5
L
L
H
L
±1.0
L
L
H
H
±1.5
L
H
L
L
±2.0
L
H
L
H
±0.5
L
H
H
L
±1.0
L
H
H
H
±1.5
H
L
L
L
±2.0
H
L
L
H
±0.5
H
L
H
L
±1.0
H
L
H
H
±1.5
H
H
L
L
±2.0
H
H
L
H
±0.5
H
H
H
L
±1.0
H
H
H
H
±1.5
25
CLK/1300
CLK/868
CLK/650
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Des — SSCG Generation — Optional
The Des provides an internally generated spread spectrum
clock (SSCG) to modulate its outputs. Both clock and data
outputs are modulated. This will aid to lower system EMI.
Output SSCG deviations to ±2% (4% total) at up to 100 kHz
modulations is available. See Table . This feature may be
controlled by external STRAP pins or by register.
EMI Reduction Features
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
TABLE 9. SSCG Configuration (LF_MODE = H) — Des Output
SSC[3:0] Inputs
LF_MODE = H (10 — 20 MHz)
Result
SSC3
SSC2
SSC1
SSC0
fdev (%)
fmod (kHz)
L
L
L
L
N/A
CLK/620
L
L
L
H
±0.5
L
L
H
L
±1.0
L
L
H
H
±1.5
L
H
L
L
±2.0
L
H
L
H
±0.5
L
H
H
L
±1.0
L
H
H
H
±1.5
H
L
L
L
±2.0
H
L
L
H
±0.5
H
L
H
L
±1.0
H
L
H
H
±1.5
H
H
L
L
±2.0
H
H
L
H
±0.5
H
H
H
L
±1.0
H
H
H
H
±1.5
CLK/370
CLK/258
CLK/192
30120973
FIGURE 24. SSCG Waveform
Power Saving Features
Des — Stop Stream SLEEPFeature
The DS92LV0422 will enter a low power SLEEP state when
the input serial stream is stopped. A STOP condition is detected when the embedded clock bits are not present. When
the serial stream starts again, the Des will then lock to the
incoming signal and recover the data. Note – in STOP CLOCK
SLEEP, the optional Serial Bus Control Registers values are
RETAINED.
Des — Power Down Feature (PDB)
The DS92LV0422 has a PDB input pin to ENABLE or POWER
DOWN the device. This pin is controlled by the host and is
used to save power, disabling the Des when the display is not
needed. An auto detect mode is also available. In this mode,
the PDB pin is tied HIGH and the Des will enter POWER
DOWN when the serial stream stops. When the serial stream
starts up again, the Des will lock to the input stream and assert
the LOCK pin and output valid data. In the POWER DOWN
mode, the LVDS data and clock output states are determined
by the OSS_SEL status. Note – in POWER DOWN, the optional Serial Bus Control Registers are RESET.
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1.8V or 3.3V VDDIO Operation
The DS92LV0422 parallel control bus can operate with 1.8 V
or 3.3 V levels (VDDIO) for host compatibility. The 1.8 V levels
will offer a system power savings.
26
An optional At-Speed Built In Self Test (BIST) feature supports the testing of the high-speed serial link. This is useful in
the prototype stage, equipment production, in-system test
and also for system diagnostics. In the BIST mode only a input
clock is required along with control to the Ser and Des BISTEN input pins. The Ser outputs a test pattern (PRBS7) and
drives the link at speed. The Des detects the PRBS7 pattern
and monitors it for errors. A PASS output pin toggles to flag
any payloads that are received with 1 to 24 errors. Upon completion of the test, the result of the test is held on the PASS
output until reset (new BIST test or Power Down). A high on
PASS indicates NO ERRORS were detected. A Low on PASS
indicates one or more errors were detected. The duration of
the test is controlled by the pulse width applied to the Des
BISTEN pin.
Inter-operability is supported between this Channel Link II device and all Channel Link II generations (Gen 1/2/3) — see
respective datasheets for details on entering BIST mode and
control.
Sample BIST Sequence
See Figure 25 for the BIST mode flow diagram.
Step 1: Place the serializer in BIST Mode by setting Ser BISTEN = H. The BIST Mode is enabled via the BISTEN pin. An
RxCLKIN is required for all the Ser options. When the deserializer detects the BIST mode pattern and command the
parallel data and control signal outputs are shut off.
Step 2: Place the deserializer in BIST mode by setting the
BISTEN = H. The Des is now in the BIST mode and checks
the incoming serial payloads for errors. If an error in the payload (1 to 24) is detected, the PASS pin will switch low for one
half of the clock period. During the BIST test, the PASS output
can be monitored and counted to determine the payload error
rate.
Step 3: To Stop the BIST mode, the deserializer BISTEN pin
is set Low. The deserializer stops checking the data and the
final test result is held on the PASS pin. If the test ran error
free, the PASS output will be High. If there was one or more
errors detected, the PASS output will be Low. The PASS output state is held until a new BIST is run, the device is RESET,
or Powered Down. The BIST duration is user controlled by the
duration of the BISTEN signal.
Step 4: To return the link to normal operation, the ser and des
BISTEN input are set Low. The Link returns to normal operation.
Figure 26 shows the waveform diagram of a typical BIST test
for two cases. Case 1 is error free, and Case 2 shows one
30120943
FIGURE 25. BIST Mode Flow Diagram
BER Calculations
It is possible to calculate the approximate Bit Error Rate
(BER). The following is required:
• Pixel Clock Frequency (MHz)
• BIST Duration (seconds)
• BIST test Result (PASS)
The BER is less than or equal to one over the product of 24
times the RxCLKIN rate times the test duration. If we assume
a 65MHz RxCLKIN, a 10 minute (600 second) test, and a
PASS, the BERT is ≤ 1.07 X 10E-12
The BIST mode runs a check on the data payload bits. The
LOCK pin also provides a link status. It the recovery of the C0
and C1 bits does not reconstruct the expected clock signal,
the LOCK pin will switch Low. The combination of the LOCK
and At-Speed BIST PASS pin provides a powerful tool for
system evaluation and performance monitoring.
27
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
with multiple errors. In most cases it is difficult to generate
errors due to the robustness of the link (differential data transmission etc.), thus they may be introduced by greatly extending the cable length, faulting the interconnect, reducing signal
condition enhancements (De-Emphasis, VODSEL, or deserializer Equalization).
Built In Self Test (BIST)
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
30120964
FIGURE 26. BIST Waveforms
of the recommended value to set other three possible addresses may be used. See Table 10.
The Serial Bus protocol is controlled by START, START-Repeated, and STOP phases. A START occurs when SCL
transitions Low while SDA is High. A STOP occurs when SDA
transition High while SCL is also HIGH. See Figure 28
Optional Serial Bus Control
The DS92LV0421 and DS92LV0422 may be configured by
the use of a serial control bus that is I2C protocol compatible.
By default, the I2C reg_0x00'h is set to 00'h and all configuration is set by control/strap pins. A write of 01'h to reg_0x00'h
will enable/allow configuration by registers; this will override
the control/strap pins. Multiple devices may share the serial
control bus since multiple addresses are supported. See Figure 27.
The serial bus is comprised of three pins. The SCL is a Serial
Bus Clock Input. The SDA is the Serial Bus Data Input / Output signal. Both SCL and SDA signals require an external pull
up resistor to VDDIO. For most applications a 4.7 kΩ pull up
resistor to 3.3V may be used. The resistor value may be adjusted for capacitive loading and data rate requirements. The
signals are either pulled High, or driven Low.
30120951
FIGURE 28. START and STOP Conditions
To communicate with a remote device, the host controller
(master) sends the slave address and listens for a response
from the slave. This response is referred to as an acknowledge bit (ACK). If a slave on the bus is addressed correctly,
it Acknowledges (ACKs) the master by driving the SDA bus
low. If the address doesn't match a device's slave address, it
Not-acknowledges (NACKs) the master by letting SDA be
pulled High. ACKs also occur on the bus when data is being
transmitted. When the master is writing data, the slave ACKs
after every data byte is successfully received. When the master is reading data, the master ACKs after every data byte is
received to let the slave know it wants to receive another data
byte. When the master wants to stop reading, it NACKs after
the last data byte and creates a stop condition on the bus. All
communication on the bus begins with either a Start condition
or a Repeated Start condition. All communication on the bus
ends with a Stop condition. A READ is shown in Figure 29
and a WRITE is shown in Figure 30.
30120941
FIGURE 27. Serial Control Bus Connection
The third pin is the ID[X] pin. This pin sets one of five possible
device addresses. Three different connections are possible.
The pin may be tied to ground. The pin may be pulled to
VDD (1.8V, NOT VDDIO)) with a 10 kΩ resistor. Or a 10 kΩ pull
up resistor (to VDD 1.8V, NOT VDDIO)) and a pull down resistor
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28
TABLE 11. ID[x] Resistor Value – DS92LV0422
TABLE 10. ID[x] Resistor Value – DS92LV0421
Resistor
RID kΩ
Address
7'b
Address
8'b
0 appended
(WRITE)
Resistor
RID kΩ
Address
7'b
Address
8'b
0 appended
(WRITE)
0.47
7b' 111 0001 (h'71)
8b' 1110 0010 (h'E2)
2.7
7b' 111 0010 (h'72)
8b' 1110 0100 (h'E4)
0.47
7b' 110 1001 (h'69)
8b' 1101 0010 (h'D2)
8.2
7b' 111 0011 (h'73)
8b' 1110 0110 (h'E6)
2.7
7b' 110 1010 (h'6A)
8b' 1101 0100 (h'D4)
Open
7b' 111 0110 (h'76)
8b' 1110 1100 (h'EC)
8.2
7b' 110 1011 (h'6B)
8b' 1101 0110 (h'D6)
Open
7b' 110 1110 (h'6E)
8b' 1101 1100 (h'DC)
30120938
FIGURE 29. Serial Control Bus — READ
30120939
FIGURE 30. Serial Control Bus — WRITE
29
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
If the Serial Bus is not required, the three pins may be left
open (NC).
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
TABLE 12. DS92LV0421 SERIALIZER — Serial Bus Control Registers
ADD ADD Register Name
(dec) (hex)
0
1
2
0
1
2
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Ser Config 1
Device ID
De-Emphasis
Control
Bit(s)
R/W
Defa Function
ult
(bin)
7
R/W
0
Reserved
Reserved
6
R/W
0
MAPSEL
0: LSB on RxIN3
1: MSB on RxIN3
5
R/W
0
Reserved
Reserved
4
R/W
0
VODSEL
0: Low
1: High
3:2
R/W
00
CONFIG
00: Control Signal Filter Disabled
01: Control Signal Filter Enabled
10: Reserved
11: Reserved
1
R/W
0
SLEEP
Note – not the same function as PowerDown (PDB)
0: normal mode
1: Sleep Mode – Register settings retained.
0
R/W
0
REG
0: Configurations set from control pins
1: Configuration set from registers (except I2C_ID)
7
R/W
0
REG ID
0: Address from ID[X] Pin
1: Address from Register
6:0
R/W
1101 ID[X]
000
Serial Bus Device ID, IDs are:
7b '1101 001 (h'69)
7b '1101 010 (h'6A)
7b '1101 011 (h'6B)
7b '1101 110 (h'6E)
All other addresses are Reserved.
7:5
R/W
000
De-E Setting
000: set by external Resistor
001: -1 dB
010: -2 dB
011: -3.3 dB
100: -5 dB
101: -6.7 dB
110: -9 dB
111: -12 dB
4
R/W
0
De-E EN
0: De-Emphasis Enabled
1: De-Emphasis Disabled
3:0
R/W
000
Reserved
Reserved
30
Description
ADD ADD Register Name
(dec) (hex)
0
1
2
0
1
2
Des Config 1
Device ID
Des Features 1
Bit(s)
R/W
Defa Function
ult
(bin)
7
R/W
0
LFMODE
SSCG Mode — low frequency support
0: 20 to 65 MHz Operation
1: 10 to 20 MHz Operation
6
R/W
0
MAPSEL
Channel Link Map Select
0: LSB on TxOUT3+/1: MSB on TxOUT3+/-
5
R/W
0
Reserved
Reserved
4
R/W
0
Reserved
Reserved
3:2
R/W
00
CONFIG
00: Control Signal Filter Disabled
01: Control Signal Filter Enabled
10: Reserved
11: Reserved
1
R/W
0
SLEEP
Note – not the same function as PowerDown (PDB)
0: normal mode
1: Sleep Mode – Register settings retained.
0
R/W
0
REG Control
0: Configurations set from control pins
1: Configuration set from registers (except I2C_ID)
7
R/W
0
REG ID
0: Address from ID[X] Pin
1: Address from Register
6:0
R/W
7
R/W
0
OEN
Output Enable Input
Table 5
6
R/W
0
OSS_SEL
Output Sleep State Select
Table 5
5:4
R/W
00
Reserved
Reserved
3
R/W
0
VODSEL
LVDS Driver Output Voltage Select
0: LVDS VOD is ±250 mV, 500 mVp-p (typ)
1: LVDS VOD is ±400 mV, 800 mVp-p (typ)
2:0
R/W
000
OSC_SEL
000: OFF
001:RESERVED
010: 25 MHz ±40%
011: 16.7 MHz ±40%
100: 12.5 MHz ±40%
101: 10 MHz ±40%
110: 8.3 MHz ±40%
111: 6.3MHz ±40%
1110 ID[X]
000
Description
Serial Bus Device ID, IDs are:
7b' 111 0001 (h'71)
7b' 111 0010 (h'72)
7b' 111 0011 (h'73)
7b' 111 0110 (h'76)
All other addresses are Reserved.
31
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
TABLE 13. DS92LV0422 DESERIALIZER — Serial Bus Control Registers
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
ADD ADD Register Name
(dec) (hex)
3
3
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Des Features 2
Bit(s)
R/W
Defa Function
ult
(bin)
Description
7:5
R/W
000
EQ Gain
000: ~1.625 dB
001: ~3.25 dB
010: ~4.87 dB
011: ~6.5 dB
100: ~8.125 dB
101: ~9.75 dB
110: ~11.375 dB
111: ~13 dB
4
R/W
0
EQ Enable
0: EQ = disabled
1: EQ = enabled
3
R/W
0
Reserved
Reserved
2:0
R/W
000
SSC
IF LFMODE = 0 then:
000: SSCG OFF
001: fdev = ±0.9%, fmod = CLK/2168
010: fdev = ±1.2%, fmod = CLK/2168
011: fdev = ±1.9%, fmod = CLK/2168
100: fdev = ±2.3%, fmod = CLK/2168
101: fdev = ±0.7%, fmod = CLK/21300
110: fdev = ±1.3%, fmod = CLK/1300
111: fdev = ±1.57%, fmod = CLK/1300
IF LFMODE = 1, then:
001: fdev = ±0.7%, fmod = CLK/625
010: fdev = ±1.3%, fmod = CLK/625
011: fdev = ±1.8%, fmod = CLK/625
100: fdev = ±2.2%, fmod = CLK/625
101: fdev = ±0.7%, fmod = CLK/385
110: fdev = ±1.2%, fmod = CLK/385
111: fdev = ±1.7%, fmod = CLK/385
32
DISPLAY APPLICATION
The DS92LV0421 and DS92LV0422 chipset is intended for
interface between a host (graphics processor) and a Display.
It supports an 24-bit color depth (RGB888) and up to 1024 X
768 display formats. In a RGB888 application, 24 color bits
(R[7:0], G[7:0], B[7:0]), Pixel Clock (PCLK) and three control
bits (VS, HS and DE) are supported across the serial link with
PCLK rates from 10 to 75 MHz. The chipset may also be used
in 18-bit color applications. In this application three to six general purpose signals may also be sent from host to display.
DS92LV0421 TYPICAL APPLICATION CONNECTION
Figure 31 shows a typical application of the DS92LV0421 for
a 75 MHz 24-bit Color Display Application. The LVDS inputs
require external 100 ohm differential termination resistors.
The CML outputs require 0.1 μF AC coupling capacitors to the
30120944
FIGURE 31. DS92LV0421 Typical Connection Diagram
33
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
line. The line driver includes internal termination. Bypass capacitors are placed near the power supply pins. At a minimum,
four 0.1 µF capacitors and a 4.7 µF capacitor should be used
for local device bypassing. System GPO (General Purpose
Output) signals control the PDB and BISTEN pins. The application assumes the companion deserializer (DS92LV0422)
therefore the configuration pins are also both tied Low. In this
example the cable is long, therefore the VODSEL pin is tied
High and a De-Emphasis value is selected by the resistor R1.
The interface to the host is with 1.8 V LVCMOS levels, thus
the VDDIO pin is connected also to the 1.8V rail. The Optional
Serial Bus Control is not used in this example, thus the SCL,
SDA and ID[x] pins are left open. A delay cap is placed on the
PDB signal to delay the enabling of the device until power is
stable. Bypass capacitors are placed near the power supply
pins. Ferrite beads are placed on the power lines for effective
noise suppression.
Applications Information
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
panion deserializer (DS92LV0422) therefore the configuration pins are also both tied Low. . The interface to the host is
with 1.8 V LVCMOS levels, thus the VDDIO pin is connected
also to the 1.8V rail. The Optional Serial Bus Control is not
used in this example, thus the SCL, SDA and ID[x] pins are
left open. A delay cap is placed on the PDB signal to delay
the enabling of the device until power is stable. Bypass capacitors are placed near the power supply pins. Ferrite beads
are placed on the power lines for effective noise suppression.
DS92LV0422 TYPICAL APPLICATION CONNECTION
shows a typical application of the DS92LV0422 for a 75 MHz
24-bit Color Display Application. The CML inputs require 0.1
μF AC coupling capacitors to the line. The line driver includes
internal termination. Bypass capacitors are placed near the
power supply pins. At a minimum, four 0.1 µF capacitors and
a 4.7 µF capacitor should be used for local device bypassing.
System GPO (General Purpose Output) signals control the
PDB and BISTEN pins. The application assumes the com-
30120974
FIGURE 32. DS92LV0422 Typical Connection Diagram
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34
Live Link Insertion
The serializer and deserializer devices support live link or cable hot plug applications. The automatic receiver lock to random data “plug & go” hot insertion capability allows the
DS92LV0422 to attain lock to the active data stream during a
live cable insertion event.
Transmission Media
The DS92LV0421 and the companion deserializer chipset is
intended to be used in a point-to-point configuration, through
a PCB trace, or through twisted pair cable. The DS92LV0421
provide internal terminations providing a clean signaling environment. The interconnect for LVDS should present a differential impedance of 100 Ohms. Use cables and connectors
that have matched differential impedance to minimize
impedance discontinuities. Shielded or un-shielded cables
Alternate Color / Data Mapping
Color Mapped data Pin names are provided to specify a recommended mapping for 24-bit and 18-bit Applications. When
connecting to earlier generations of Channel Link II deserializer devices, a color mapping review is recommended to
ensure the correct connectivity is obtained. Table 14 provides
examples for interfacing between DS92LV0421 and different
deserializers.
TABLE 14. Serializer Alternate Color / Data Mapping
Channel Link
Bit Number
RGB (LSB
Example)
DS92LV2422
RxIN3
Bit 26
B1
B1
Bit 25
B0
B0
Bit 24
G1
G1
Bit 23
G0
G0
Bit 22
R1
R1
Bit 21
R0
R0
Bit 20
DE
DE
ROUT20
Bit 19
VS
VS
ROUT19
ROUT19
Bit 18
HS
HS
ROUT18
ROUT18
Bit 17
B7
B7
ROUT17
ROUT17
Bit 16
B6
B6ROUT10
ROUT16
ROUT16
Bit 15
B5
B5
ROUT15
ROUT15
Bit 14
B4
B4
ROUT14
ROUT14
Bit 13
B3
B3
ROUT13
Bit 12
B2
B2
ROUT12
ROUT12
Bit 11
G7
G7
ROUT11
ROUT11
Bit 10
G6
G6
ROUT10
ROUT10
Bit 9
G5
G5
ROUT9
ROUT9
Bit 8
G4
G4
ROUT8
ROUT8
Bit 7
G3
G3
ROUT7
Bit 6
G2
G2
ROUT6
Bit 5
R7
R7
ROUT5
ROUT5
Bit 4
R6
R6
ROUT4
ROUT4
Bit 3
R5
R5
ROUT3
ROUT3
Bit 2
R4
R4
ROUT2
ROUT2
Bit 1
R3
R3
ROUT1
ROUT1
Bit 0
R2
RxIN2
RxIN1
RxIN0
N/A
DS92LV0421
Settings
MAPSEL = 0
DS90C124
N/A
TxOUT2
TxOUT1
ROUT20
ROUT13
ROUT7
TxOUT0
ROUT6
R2
ROUT0
N/A
ROUT23
OS2
ROUT23
ROUT22
OS1
ROUT22
ROUT21
OS0
CONFIG [1:0] = 00
35
DS90UR124 DS99R124Q
ROUT0
CONFIG [1:0] = 10
ROUT21
CONFIG [1:0] = 11
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DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
may be used depending upon the noise environment and application requirements.
Power Up Requirements and PDB Pin
The VDD (VDDn and VDDIO) supply ramp should be faster than
1.5 ms with a monotonic rise. If slower then 1.5 ms then a
capacitor on the PDB pin is needed to ensure PDB arrives
after all the VDD have settled to the recommended operating
voltage. When PDB pin is pulled to VDDIO, it is recommended
to use a 10 kΩ pull-up and a 22 uF cap to GND to delay the
PDB input signal.
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
TABLE 15. Deserializer Alternate Color / Data Mapping
Channel Link
Bit Number
RGB (LSB
Example)
DS92LV2421
TxOUT3
Bit 26
B1
B1
TxOUT2
TxOUT1
TxOUT0
N/A
Bit 25
B0
B0
G1
G1
Bit 23
G0
G0
Bit 22
R1
R1
Bit 21
R0
R0
Bit 20
DE
DE
DIN20
Bit 19
VS
VS
DIN19
DIN19
Bit 18
HS
HS
DIN18
DIN18
Bit 17
B7
B7
DIN17
DIN17
Bit 16
B6
B6ROUT10
DIN16
DIN16
Bit 15
B5
B5
DIN15
DIN15
Bit 14
B4
B4
DIN14
Bit 13
B3
B3
DIN13
RxIN2
DIN20
DIN14
RxIN1
DIN13
Bit 12
B2
B2
DIN12
DIN12
Bit 11
G7
G7
DIN11
DIN11
Bit 10
G6
G6
DIN10
DIN10
Bit 9
G5
G5
DIN9
DIN9
Bit 8
G4
G4
DIN8
DIN8
Bit 7
G3
G3
DIN7
Bit 6
G2
G2
DIN6
Bit 5
R7
R7
DIN5
DIN5
Bit 4
R6
R6
DIN4
DIN4
Bit 3
R5
R5
DIN3
DIN3
Bit 2
R4
R4
DIN2
DIN2
Bit 1
R3
R3
DIN1
DIN1
Bit 0
R2
R2
DIN0
DIN0
N/A
DIN923
OS2
DIN923
DIN922
OS1
DIN922
DIN921
OS0
DIN921
MAPSEL = 0
CONFIG [1:0] = 00
DIN7
RxIN0
CONFIG [1:0] = 10
DIN6
CONFIG [1:0] = 11
capacitor is recommend at the point of power entry. This is
typically in the 50uF to 100uF range and will smooth low frequency switching noise. It is recommended to connect power
and ground pins directly to the power and ground planes with
bypass capacitors connected to the plane with via on both
ends of the capacitor. Connecting power or ground pins to an
external bypass capacitor will increase the inductance of the
path.
A small body size X7R chip capacitor, such as 0603, is recommended for external bypass. Its small body size reduces
the parasitic inductance of the capacitor. The user must pay
attention to the resonance frequency of these external bypass
capacitors, usually in the range of 20-30 MHz. To provide effective bypassing, multiple capacitors are often used to
achieve low impedance between the supply rails over the frequency of interest. At high frequency, it is also a common
practice to use two vias from power and ground pins to the
planes, reducing the impedance at high frequency.
Some devices provide separate power and ground pins for
different portions of the circuit. This is done to isolate switch-
PCB LAYOUT AND POWER SYSTEM CONSIDERATIONS
Circuit board layout and stack-up for the LVDS devices should
be designed to provide low-noise power feed to the device.
Good layout practice will also separate high frequency or
high-level inputs and outputs to minimize unwanted stray
noise pickup, feedback and interference. Power system performance may be greatly improved by using thin dielectrics (2
to 4 mils) for power / ground sandwiches. This arrangement
provides plane capacitance for the PCB power system with
low-inductance parasitics, which has proven especially effective at high frequencies, and makes the value and placement
of external bypass capacitors less critical. External bypass
capacitors should include both RF ceramic and tantalum electrolytic types. RF capacitors may use values in the range of
0.01 uF to 0.1 uF. Tantalum capacitors may be in the 2.2 uF
to 10 uF range. Voltage rating of the tantalum capacitors
should be at least 5X the power supply voltage being used.
Surface mount capacitors are recommended due to their
smaller parasitics. When using multiple capacitors per supply
pin, locate the smaller value closer to the pin. A large bulk
www.national.com
DS90C241
Bit 24
N/A
DS92LV0422
Settings
DS90UR241 DS99R421Q
36
LVDS INTERCONNECT GUIDELINES
See AN-1108 and AN-905 for full details.
• Use 100Ω coupled differential pairs
• Use the S/2S/3S rule in spacings
– S = space between the pair
– 2S = space between pairs
– 3S = space to LVCMOS signal
• Minimize the number of Vias
• Use differential connectors when operating above
500Mbps line speed
• Maintain balance of the traces
• Minimize skew within the pair
• Terminate as close to the TX outputs and RX inputs as
possible
Additional general guidance can be found in the LVDS
Owner’s Manual - available in PDF format from the National
web site at: www.national.com/lvds
37
www.national.com
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
ing noise effects between different sections of the circuit.
Separate planes on the PCB are typically not required. Pin
Description tables typically provide guidance on which circuit
blocks are connected to which power pin pairs. In some cases, an external filter many be used to provide clean power to
sensitive circuits such as PLLs.
Use at least a four layer board with a power and ground plane.
Locate LVCMOS signals away from the LVDS lines to prevent
coupling from the LVCMOS lines to the LVDS lines. Closelycoupled differential lines of 100 Ohms are typically recommended for LVDS interconnect. The closely coupled lines
help to ensure that coupled noise will appear as commonmode and thus is rejected by the receivers. The tightly coupled lines will also radiate less.
Information on the LLP style package is provided in National
Application Note: AN-1187.
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Physical Dimensions inches (millimeters) unless otherwise noted
DS92LV0421 36–pin LLP Package (6.0 mm X 6.0 mm X 0.8 mm, 0.5 mm pitch)
NS Package Number SQA36A
DS92LV0422 48–pin LLP Package (7.0 mm X 7.0 mm X 0.8 mm, 0.5 mm pitch)
NS Package Number SQA48A
www.national.com
38
www.national.com
39
DS92LV0421 / DS92LV0422 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel Interface
Notes
DS92LV0421 / DS92LV04225 10 - 75 MHz Channel Link II Serializer/Deserializer with LVDS Parallel
Interface
Notes
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