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 www.national.com 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 www.national.com 2 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 www.national.com 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. www.national.com 4 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 14 FIGURE 5. DS92LV0421 Channel Link Receiver Strobe Positions www.national.com 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 www.national.com 16 FIGURE 9. DS92LV0421 Disable Time 30120910 FIGURE 10. DS92LV0421 Latency Delay 30120967 FIGURE 11. DS92LV0422 Latency Delay 17 www.national.com 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 www.national.com 18 FIGURE 14. DS92LV0422 Power Down Delay 30120980 FIGURE 15. DS92LV0422 Enable Delay 30120932 FIGURE 16. Checkerboard Data Pattern 19 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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. www.national.com 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 www.national.com 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. www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 www.national.com 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 For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Design Support Amplifiers www.national.com/amplifiers WEBENCH® Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage References www.national.com/vref Design Made Easy www.national.com/easy www.national.com/powerwise Applications & Markets www.national.com/solutions Mil/Aero www.national.com/milaero PowerWise® Solutions Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors SolarMagic™ www.national.com/solarmagic PLL/VCO www.national.com/wireless www.national.com/training PowerWise® Design University THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. 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