HDMI/DVI TMDS Equalizer ADV3003 FEATURES FUNCTIONAL BLOCK DIAGRAM PE_EN TX_EN PARALLEL CONTROL VTTI IP[3:0] IN[3:0] AVEE CONTROL LOGIC + 4 – 4 EQ BUFFER HIGH SPEED VTTO PE 4 + 4 – OP[3:0] ON[3:0] BUFFERED Figure 1. TYPICAL APPLICATION DIAGRAM HDTV SET MEDIA CENTER HDMI RECEIVER GAME CONSOLE SET-TOP BOX 4:1 HDMI SWITCH APPLICATIONS ADV3003 BACK PANEL CONNECTORS FRONT PANEL CONNECTOR 07212-002 DVD PLAYER Multiple input displays Advanced television set (HDTV) front panel connectors HDMI/DVI cable extenders Figure 2. GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The ADV3003 is a 4-channel transition minimized differential signaling (TMDS) buffer featuring equalized inputs and pre-emphasized outputs. The ADV3003 features 50 Ω input and output terminations, providing full-swing output signal recovery and minimizing reflections for improved system signal integrity. The ADV3003 is targeted at HDMI™/DVI applications and is ideal for use in systems with long cable runs, long PCB traces, and designs with interior cabling. 1. The ADV3003 is provided in a 40-lead, LFCSP, surface-mount, RoHS-compliant, plastic package and is specified to operate over the −40°C to +85°C temperature range. AVCC ADV3003 07212-001 One input, one output HDMI/DVI high speed signal equalizer/driver Enables HDMI 1.3 receive-compliant input Four TMDS channels per input/output Supports 250 Mbps to 2.25 Gbps data rates Supports 25 MHz to 225 MHz pixel clocks Fully buffered unidirectional inputs/outputs Equalized inputs for operation with long HDMI cables (20 meters at 2.25 Gbps) Pre-emphasized outputs Matched 50 Ω input and output on-chip terminations Low added jitter Transmitter disable feature Reduces power dissipation Disables input terminations Single-supply operation (3.3 V) Standards compliant: HDMI receiver, DVI 40-lead, 6 mm × 6 mm, RoHS-compliant LFCSP 2. 3. 4. 5. 6. Supports data rates up to 2.25 Gbps, enabling 1080p deep color (12-bit color) HDMI formats and greater than UXGA (1600 × 1200) DVI resolutions. The 12 dB input cable equalizer enables the use of long cables at the input. For a typical 24 AWG cable, the ADV3003 compensates for more than 20 meters at data rates up to 2.25 Gbps. The selectable 6 dB of output pre-emphasis allows the ADV3003 to drive high loss output cables or long PCB traces. Matched 50 Ω on-chip input and output terminations improve system signal integrity. An external control pin, PE_EN, sets the output pre-emphasis to either 0 dB or 6 dB. An external control pin, TX_EN, simultaneously disables both the transmitter and the on-chip input terminations. This feature reduces the power dissipation of the ADV3003 and indicates to a connected source when the ADV3003 is disabled. Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2008 Analog Devices, Inc. All rights reserved. ADV3003 TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ..............................................6 Applications ....................................................................................... 1 Theory of Operation ...................................................................... 10 Functional Block Diagram .............................................................. 1 Introduction ................................................................................ 10 Typical Application Diagram .......................................................... 1 Input Channels ........................................................................... 10 General Description ......................................................................... 1 Output Channels ........................................................................ 10 Product Highlights ........................................................................... 1 Application Notes ........................................................................... 12 Revision History ............................................................................... 2 Pinout ........................................................................................... 12 Specifications..................................................................................... 3 Cable Lengths and Equalization ............................................... 12 Absolute Maximum Ratings............................................................ 4 Pre-Emphasis .............................................................................. 12 Thermal Resistance ...................................................................... 4 PCB Layout Guidelines.............................................................. 12 Maximum Power Dissipation ..................................................... 4 Outline Dimensions ....................................................................... 15 ESD Caution .................................................................................. 4 Ordering Guide .......................................................................... 15 Pin Configuration and Function Descriptions ............................. 5 REVISION HISTORY 2/08—Revision 0: Initial Version Rev. 0 | Page 2 of 16 ADV3003 SPECIFICATIONS TA = 27°C, AVCC = 3.3 V, VTTI = 3.3 V, VTTO = 3.3 V, AVEE = 0 V, differential input swing = 1000 mV, pattern = PRBS 27 − 1, data rate = 2.25 Gbps, TMDS outputs terminated with external 50 Ω resistors to 3.3 V, unless otherwise noted. Table 1. Parameter DYNAMIC PERFORMANCE Maximum Data Rate (DR) per Channel Bit Error Rate (BER) Added Deterministic Jitter Added Random Jitter Differential Intrapair Skew Differential Interpair Skew 1 EQUALIZATION PERFORMANCE Receiver (Fixed Setting) 2 Transmitter (Pre-Emphasis On) 3 INPUT CHARACTERISTICS Input Voltage Swing Input Common-Mode Voltage (VICM) OUTPUT CHARACTERISTICS 4 High Voltage Level Low Voltage Level Rise/Fall Time (20% to 80%) TERMINATION Input Termination Resistance Output Termination Resistance POWER SUPPLY AVCC QUIESCENT CURRENT AVCC VTTI VTTO Conditions/Comments Min NRZ PRBS 223 − 1 DR ≤ 2.25 Gbps, PRBS 27 − 1 2.25 Typ Max Unit Gbps 10−9 At output At output 25 1 1 50 ps (p-p) ps (rms) ps ps Boost frequency = 1.125 GHz Boost frequency = 1.125 GHz 12 6 dB dB Differential 150 AVCC − 800 1200 AVCC mV mV Single-ended high speed channel Single-ended high speed channel AVCC − 200 AVCC − 600 75 AVCC + 10 AVCC − 400 178 mV mV ps Single-ended Single-ended 50 50 Operating range (3.3 V ± 10%) 3 Ω Ω 3.3 3.6 V Output disabled Output enabled, pre-emphasis off Output enabled, pre-emphasis on Input termination on 5 Output termination on, pre-emphasis off Output termination on, pre-emphasis on Output disabled 20 32 66 40 40 80 0 40 50 80 54 50 100 1 mA mA mA mA mA mA mA Output disabled Output enabled, pre-emphasis off Output enabled, pre-emphasis on TX_EN, PE_EN 66 370 686 148 553 937 mW mW mW 0.8 V V POWER DISSIPATION 6 PARALLEL CONTROL INTERFACE Input High Voltage, VIH Input Low Voltage, VIL 2 1 Differential interpair skew is measured between the TMDS pairs of the HDMI/DVI link. ADV3003 output meets the transmitter eye diagram mask as defined in the HDMI Standard Version 1.3a and the DVI Standard Version 1.0. 3 Cable output meets the receiver eye diagram mask as defined in the HDMI Standard Version 1.3a and the DVI Standard Version 1.0. 4 PE = 0 dB. 5 Typical value assumes the HDMI/DVI link is active with nominal signal swings. Minimum and maximum limits are measured at the extremes of input termination resistance and input voltage swing, respectively . 6 The total power dissipation excludes power dissipated in the 50 Ω off-chip loads. 2 Rev. 0 | Page 3 of 16 ADV3003 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 2. Parameter AVCC to AVEE VTTI VTTO Internal Power Dissipation High Speed Input Voltage High Speed Differential Input Voltage Parallel Interface (TX_EN, PE_EN) Storage Temperature Range Operating Temperature Range Junction Temperature Rating 3.7 V AVCC + 0.6 V AVCC + 0.6 V 2.0 W AVCC − 1.4 V < VIN < AVCC + 0.6 V 2.0 V AVEE − 0.3 V < VIN < AVCC + 0.6 V −65°C to +125°C −40°C to +85°C 150°C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. θJA is specified for the worst-case conditions, that is, a device soldered in a 4-layer JEDEC circuit board for surface-mount packages. JC is specified for the exposed pad soldered to the circuit board with no airflow. Table 3. Package Type 40-Lead LFCSP θJA 31.9 θJC 2.6 Unit °C/W MAXIMUM POWER DISSIPATION The maximum power that can be safely dissipated by the ADV3003 is limited by the associated rise in junction temperature. The maximum safe junction temperature for plastic encapsulated devices is determined by the glass transition temperature of the plastic, approximately 150°C. Temporarily exceeding this limit may cause a shift in parametric performance due to a change in the stresses exerted on the die by the package. Exceeding a junction temperature of 175°C for an extended period can result in device failure. To ensure proper operation, it is necessary to observe the maximum power derating as determined by the thermal resistance coefficients. ESD CAUTION Rev. 0 | Page 4 of 16 ADV3003 40 39 38 37 36 35 34 33 32 31 NC NC NC AVEE NC NC NC NC AVCC NC PIN CONFIGURATION AND FUNCTION DESCRIPTIONS PIN 1 INDICATOR ADV3003 TOP VIEW (Not to Scale) 30 29 28 27 26 25 24 23 22 21 AVCC PE_EN TX_EN AVEE AVCC AVCC AVEE AVCC AVCC NC NOTES 1. NC = NO CONNECT. 2. THE ADV3003 LFCSP HAS AN EXPOSED PADDLE (ePAD) ON THE UNDERSIDE OF THE PACKAGE, WHICH AIDS IN HEAT DISSIPATION. THE ePAD MUST BE ELECTRICALLY CONNECTED TO THE AVEE SUPPLY PLANE TO MEET ELECTRICAL AND THERMAL SPECIFICATIONS. 07212-003 ON0 OP0 VTTO ON1 OP1 AVCC ON2 OP2 ON3 OP3 11 12 13 14 15 16 17 18 19 20 IN0 1 IP0 2 IN1 3 IP1 4 VTTI 5 IN2 6 IP2 7 IN3 8 IP3 9 AVCC 10 Figure 3. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 2 3 4 5 6 7 8 9 10, 16, 22, 23, 25, 26, 30, 32 11 12 13 14 15 17 18 19 20 24, 27, 37, ePAD 28 29 21, 31, 33, 34, 35, 36, 38, 39, 40 1 Mnemonic IN0 IP0 IN1 IP1 VTTI IN2 IP2 IN3 IP3 AVCC ON0 OP0 VTTO ON1 OP1 ON2 OP2 ON3 OP3 AVEE TX_EN PE_EN NC Type 1 HS, I HS, I HS, I HS, I Power HS, I HS, I HS, I HS, I Power HS, O HS, O Power HS, O HS, O HS, O HS, O HS, O HS, O Power Control Control NC Description High Speed Input Complement. High Speed Input. High Speed Input Complement. High Speed Input. Input Termination Supply. Nominally connected to AVCC. High Speed Input Complement. High Speed Input. High Speed Input Complement. High Speed Input. Positive Analog Supply. 3.3 V nominal. High Speed Output Complement. High Speed Output. Output Termination Supply. Nominally connected to AVCC. High Speed Output Complement. High Speed Output. High Speed Output Complement. High Speed Output. High Speed Output Complement. High Speed Output. Negative Analog Supply. 0 V nominal. High Speed Output Enable Parallel Interface. High Speed Pre-Emphasis Enable Parallel Interface. No Connect. HS = high speed, I = input, O = output. Rev. 0 | Page 5 of 16 ADV3003 TYPICAL PERFORMANCE CHARACTERISTICS TA = 27°C, AVCC = 3.3 V, VTTI = 3.3 V, VTTO = 3.3 V, AVEE = 0 V, differential input swing = 1000 mV, pattern = PRBS 27 − 1, data rate = 2.25 Gbps, TMDS outputs terminated with external 50 Ω resistors to 3.3 V, unless otherwise noted. HDMI CABLE ADV3003 DIGITAL PATTERN GENERATOR SERIAL DATA ANALYZER EVALUATION BOARD REFERENCE EYE DIAGRAM AT TP1 TP1 TP2 TP3 07212-004 SMA COAX CABLE 0.125UI/DIV AT 2.25Gbps 0.125UI/DIV AT 2.25Gbps 07212-008 0.125UI/DIV AT 2.25Gbps Figure 6. Rx Eye Diagram at TP2 (Cable = 20 Meters, 24 AWG) 07212-006 250mV/DIV Figure 7. Rx Eye Diagram at TP3, EQ = 12 dB (Cable = 2 Meters, 24 AWG) 250mV/DIV Figure 5. Rx Eye Diagram at TP2 (Cable = 2 Meters, 24 AWG) 07212-007 250mV/DIV 0.125UI/DIV AT 2.25Gbps 07212-005 250mV/DIV Figure 4. Test Circuit Diagram for Rx Eye Diagrams Figure 8. Rx Eye Diagram at TP3, EQ = 12 dB (Cable = 20 Meters, 24 AWG) Rev. 0 | Page 6 of 16 ADV3003 TA = 27°C, AVCC = 3.3 V, VTTI = 3.3 V, VTTO = 3.3 V, AVEE = 0 V, differential input swing = 1000 mV, pattern = PRBS 27 − 1, data rate = 2.25 Gbps, TMDS outputs terminated with external 50 Ω resistors to 3.3 V, unless otherwise noted. HDMI CABLE ADV3003 DIGITAL PATTERN GENERATOR SERIAL DATA ANALYZER EVALUATION BOARD REFERENCE EYE DIAGRAM AT TP1 TP1 TP2 TP3 07212-009 SMA COAX CABLE 0.125UI/DIV AT 2.25Gbps 0.125UI/DIV AT 2.25Gbps 07212-013 0.125UI/DIV AT 2.25Gbps Figure 11. Tx Eye Diagram at TP2, PE = 6 dB 07212-011 250mV/DIV Figure 12. Tx Eye Diagram at TP3, PE = 0 dB (Cable = 6 Meters, 24 AWG) 250mV/DIV Figure 10. Tx Eye Diagram at TP2, PE = 0 dB 07212-012 250mV/DIV 0.125UI/DIV AT 2.25Gbps 07212-010 250mV/DIV Figure 9. Test Circuit Diagram for Tx Eye Diagrams Figure 13. Tx Eye Diagram at TP3, PE = 6 dB (Cable = 10 Meters, 24 AWG) Rev. 0 | Page 7 of 16 ADV3003 TA = 27°C, AVCC = 3.3 V, VTTI = 3.3 V, VTTO = 3.3 V, AVEE = 0 V, differential input swing = 1000 mV, pattern = PRBS 27 − 1, data rate = 2.25 Gbps, TMDS outputs terminated with external 50 Ω resistors to 3.3 V, unless otherwise noted. 0.6 0.6 ALL CABLES = 24 AWG PE = 6dB 0.5 0.5 0.4 0.4 JITTER (UI) JITTER (UI) ALL CABLES = 24 AWG 1080p, 12- BIT 0.3 1.65Gbps 0.2 0.3 1080p, 12-BIT 0.2 1080p, 8-BIT 720p/1080i, 8-BIT 1080p, 8-BIT 1.65Gbps 0.1 720p/1080i, 8-BIT 480p, 8-BIT 480p, 8-BIT 0 5 10 15 25 20 INPUT CABLE LENGTH (m) 0 07212-014 0 4 6 8 10 12 14 16 OUTPUT CABLE LENGTH (m) Figure 14. Jitter vs. Input Cable Length (See Figure 4 for Test Setup) Figure 17. Jitter vs. Output Cable Length (See Figure 9 for Test Setup) 50 1.2 1.0 1080p, 12-BIT EYE HEIGHT (V) 40 JITTER (ps) 2 0 07212-017 0.1 1080p, 8-BIT 30 720p/1080i, 8-BIT 20 0.8 0.6 0.4 DJ p-p 10 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 DATA RATE (Gbps) 0 07212-015 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 DATA RATE (Gbps) Figure 15. Jitter vs. Data Rate 07212-018 0.2 RJ rms Figure 18. Eye Height vs. Data Rate 1.2 50 1.0 40 EYE HEIGHT (V) 30 20 10 0.8 0.6 0.4 0.2 3.1 3.2 3.3 3.4 SUPPLY VOLTAGE (V) 3.5 3.6 Figure 16. Jitter vs. Supply Voltage 0 3.0 3.1 3.2 3.3 3.4 3.5 SUPPLY VOLTAGE (V) Figure 19. Eye Height vs. Supply Voltage Rev. 0 | Page 8 of 16 3.6 07212-019 RJ rms 0 3.0 07212-016 JITTER (ps) DJ p-p ADV3003 TA = 27°C, AVCC = 3.3 V, VTTI = 3.3 V, VTTO = 3.3 V, AVEE = 0 V, differential input swing = 1000 mV, pattern = PRBS 27 − 1, data rate = 2.25 Gbps, TMDS outputs terminated with external 50 Ω resistors to 3.3 V, unless otherwise noted. 80 50 45 70 40 60 JITTER (ps) JITTER (ps) 35 50 40 DJ p-p 30 DJ p-p 30 25 20 15 20 10 5 RJ rms RJ rms 0 0.5 1.0 1.5 2.0 DIFFERENTIAL INPUT VOLTAGE SWING (V) 0 2.5 07212-020 0 2.9 3.1 3.3 3.5 3.7 INPUT COMMON-MODE VOLTAGE (V) Figure 20. Jitter vs. Differential Input Voltage Swing Figure 23. Jitter vs. Input Common-Mode Voltage 50 DIFFERENTIAL INPUT RESISTANCE (Ω) 120 40 JITTER (ps) 2.7 07212-023 10 30 DJ p-p 20 10 115 110 105 100 95 90 85 –15 10 35 60 85 TEMPERATURE (°C) Figure 21. Jitter vs. Temperature 140 100 FALL 60 40 20 –20 0 20 40 60 80 TEMPERATURE (°C) 100 07212-022 RISE AND FALL TIME (ps) RISE 120 0 –40 –20 0 20 40 60 80 TEMPERATURE (°C) Figure 24. Differential Input Resistance vs. Temperature 160 80 80 –40 Figure 22. Rise and Fall Time vs. Temperature Rev. 0 | Page 9 of 16 100 07212-024 0 –40 07212-021 RJ rms ADV3003 THEORY OF OPERATION INTRODUCTION The primary function of the ADV3003 is to buffer the four high speed channels of a single HDMI or DVI link. The HDMI/DVI link consists of four differential, high speed channels and four auxiliary single-ended, low speed control signals. The high speed channels include a data-word clock and three transition minimized differential signaling (TMDS) data channels running at 10× the data-word clock frequency for data rates up to 2.25 Gbps. All four high speed TMDS channels on the ADV3003 are identical; that is, the pixel clock can be run on any of the four TMDS channels. Receive channel compensation (12 dB of fixed equalization) is provided for the high speed channels to support long input cables. The ADV3003 also includes selectable pre-emphasis for driving high loss output cables or long PCB traces. The input equalizer provides 12 dB of high frequency boost. No specific cable length is suggested for this equalization level because cable performance varies widely among manufacturers; however, in general, the ADV3003 does not degrade input signals, even for short input cables. The ADV3003 can equalize more than 20 meters of a 24 AWG cable at 2.25 Gbps, for reference cables that exhibit an insertion loss of −15 dB at the fundamental frequency of this data rate. OUTPUT CHANNELS Each high speed output differential pair of the ADV3003 terminates to the 3.3 V VTTO power supply through two single-ended 50 Ω on-chip resistors, as shown in Figure 26. VTTO 50Ω 50Ω OP[3:0] ON[3:0] In the intended application, the ADV3003 is placed between a source and a sink, with long cable runs at both the input and the output. TX_EN INPUT CHANNELS VTTI 50Ω 50Ω AVEE Figure 26. High Speed Output Simplified Schematic The output termination resistors of the ADV3003 back-terminate the output TMDS transmission lines. These back-terminations, as recommended in the HDMI 1.3 specification, act to absorb reflections from impedance discontinuities on the output traces, improving the signal integrity of the output traces and adding flexibility to how the output traces can be routed. For example, interlayer vias can be used to route the ADV3003 TMDS outputs on multiple layers of the PCB without severely degrading the quality of the output signal. TX_EN IP[3:0] IN[3:0] 07212-025 CABLE EQ AVEE 07212-026 IOUT Each high speed input differential pair terminates to the 3.3 V VTTI power supply through a pair of single-ended 50 Ω on-chip resistors, as shown in Figure 25. When the transmitter of the ADV3003 is disabled by setting the TX_EN control pin as shown in Table 5, the input termination resistors are also disabled to provide a high impedance node at the inputs. Disabling the input terminations when the transmitter is disabled indicates to any connected HDMI sources that the link through the ADV3003 is inactive. Figure 25. High Speed Input Simplified Schematic Rev. 0 | Page 10 of 16 ADV3003 The ADV3003 has an external control pin, TX_EN. The TX_EN pin must be connected to either a logic high (1) or low (0), in accordance with the logic values set forth in Table 1. The use of the TX_EN pin is described in Table 5. When the transmitter is enabled by setting TX_EN to 1, both the input and output terminations are enabled. Setting TX_EN to 0 disables the transmitter, reducing power when the transmitter is not in use. When the transmitter is disabled, the input termination resistors are also disabled to present a high impedance state at the input and indicate to any connected HDMI sources that the link through the ADV3003 is inactive. Table 5. Transmitter Enable Setting TX_EN 0 1 Input Termination Off On Transmitter State Off On Output Termination On On The ADV3003 also includes two levels of programmable output pre-emphasis, 0 dB and 6 dB. The output pre-emphasis level can be manually configured by setting the PE_EN pin. The PE_EN pin must be connected to either a logic high (1) or low (0), in accordance with the logic values set forth in Table 1. The use of the PE_EN pin is described in Table 6. No specific cable length is suggested for use with either pre-emphasis setting, because cable performance varies widely among manufacturers. Table 6. Pre-Emphasis Enable Setting PE_EN 0 1 Boost 0 dB 6 dB In a typical application, the output of the ADV3003 is connected to the input of an HDMI/DVI receiver, which provides a second set of matched terminations in accordance with the HDMI 1.3 specification. If neither receiver nor receiver termination is connected to the output of the ADV3003 in the end-application, each ADV3003 output pin should be tied to 3.3 V through a 50 Ω resistor. Rev. 0 | Page 11 of 16 ADV3003 APPLICATION NOTES The ADV3003 is a TMDS buffer featuring equalized inputs and pre-emphasized outputs. It is intended for use as a buffer in HDMI/DVI systems with long input cable runs, and is fully HDMI 1.3 receive-compliant. PINOUT The ADV3003 is designed to have an HDMI/DVI receiver pinout at its input and a transmitter pinout at its output. This makes the ADV3003 ideal for use in advanced TV front-panel connectors and AVR-type applications where a designer routes both the inputs and the outputs directly to HDMI/DVI connectors—all of the high speed signals can be routed on one side of the board. The ADV3003 provides 12 dB of input equalization, so it can compensate for the signal degradation of long input cables. In addition, the ADV3003 can also provide up to 6 dB of pre-emphasis that boosts the output TMDS signals and allows the ADV3003 to precompensate when driving long PCB traces or high loss output cables. The net effect of the input equalization and output pre-emphasis is that the ADV3003 can compensate for signal degradation of both the input and output cables; it acts to reopen a closed input data eye and transmit a full-swing HDMI signal to an end receiver. PRE-EMPHASIS The pre-emphasis of the ADV3003 acts to boost the initial voltage swing of the output signals. Pre-emphasis provides a distinct advantage in systems where the ADV3003 is driving either high loss cables or long PCB traces, because the added boost helps to ensure that the data eye at the far end of the output cables or PCB traces meets the HDMI receive mask. The use of pre-emphasis in a system is highly application specific. PCB LAYOUT GUIDELINES The ADV3003 is a 4-channel TMDS buffer, targeted for use in HDMI and DVI video applications. Although the HDMI/DVI link consists of four differential, high speed channels and four single-ended, low speed auxiliary control signals, the ADV3003 buffers only the high speed signals. The high speed signals carry the audiovisual (AV) data, which is encoded by a technique called TMDS. For HDMI, the TMDS data is further encrypted in accordance with the high bandwidth digital content protection (HDCP) standard. The length of cable that can be used in a typical HDMI/DVI application depends on a large number of factors including The TMDS signals are differential, unidirectional, and high speed (up to 2.25 Gbps). The channels that carry the video data must have a controlled impedance, be terminated at the receiver, and be capable of operating up to at least 2.25 Gbps. It is especially important to note that the PCB traces that carry the TMDS signals should be designed with a controlled differential impedance of 100 Ω. The ADV3003 provides single-ended 50 Ω terminations on chip for both its inputs and outputs. Transmitter termination is not fully specified by the HDMI standard, but its inclusion in the ADV3003 improves the overall system signal integrity. • TMDS Signals CABLE LENGTHS AND EQUALIZATION The 12 dB equalizer of the ADV3003 is optimized for video data rates of 2.25 Gbps and can equalize more than 20 meters of 24 AWG HDMI cable at the input at 2.25 Gbps, the data rate corresponding to the video format 1080p with 12-bit deep color. • • • Cable quality: The quality of the cable in terms of conductor wire gauge and shielding. Thicker conductors have lower signal degradation per unit length. Data rate: The data rate being sent over the cable. The signal degradation over HDMI cables increases with data rate. Edge rates: The edge rates of the source. Slower input edges result in more significant data eye closure at the end of a cable. Receiver sensitivity: The sensitivity of the terminating receiver. Because of these considerations, specific cable types and lengths are not recommended for use with this equalizer. The ADV3003 equalizer does not degrade signal integrity, even for short input cables. In the HDMI/DVI standard, four differential pairs carry the TMDS signals. In DVI, three of these pairs are dedicated to carrying RGB video and sync data. For HDMI, audio data is also interleaved with the video data; the DVI standard does not incorporate audio information. The fourth high speed differential pair is used for the AV data-word clock, which runs at one-tenth the speed of the video data channels. The four high speed channels of the ADV3003 are identical. No concession was made to lower the bandwidth of the fourth channel for the pixel clock, so any channel can be used for any TMDS signal; the user chooses which signal is routed over which channel. In addition, the TMDS channels are symmetric; therefore, the p and n of a given differential pair are interchangeable, provided the inversion is consistent across all inputs and outputs of the ADV3003. Rev. 0 | Page 12 of 16 ADV3003 Layout for the TMDS Signals The TMDS differential pairs can either be microstrip traces, routed on the outer layer of a board, or stripline traces, routed on an internal layer of the board. If microstrip traces are used, there should be a continuous reference plane on the PCB layer directly below the traces. If stripline traces are used, they must be sandwiched between two continuous reference planes in the PCB stack-up. Additionally, the p and n of each differential pair must have a controlled differential impedance of 100 Ω. The characteristic impedance of a differential pair is a function of several variables including the trace width, the distance separating the two traces, the spacing between the traces and the reference plane, and the dielectric constant of the PC board binder material. Interlayer vias introduce impedance discontinuities that can cause reflections and jitter on the signal path; therefore, it is preferable to route the TMDS lines exclusively on one layer of the board, particularly for the input traces. In addition, to prevent unwanted signal coupling and interference, route the TMDS signals away from other signals and noise sources on the PCB. Both traces of a given differential pair must be equal in length to minimize intrapair skew. Maintaining the physical symmetry of a differential pair is integral to ensuring its signal integrity; excessive intrapair skew can introduce jitter through duty cycle distortion (DCD). The p and n of a given differential pair should always be routed together to establish the required 100 Ω differential impedance. Enough space should be left between the differential pairs of a given group so that the n of one pair does not couple to the p of another pair. For example, one technique is to make the interpair distance 4× to 10× wider than the intrapair spacing. Any group of four TMDS channels (input or output) should have closely matched trace lengths to minimize interpair skew. Severe interpair skew can cause the data on the four different channels of a group to arrive out of alignment with one another. A good practice is to match the trace lengths for a given group of four channels to within 0.05 inches on FR4 material. The length of the TMDS traces should be minimized to reduce overall signal degradation. Commonly used PC board material such as FR4 is lossy at high frequencies, so long traces on the circuit board increase signal attenuation, resulting in decreased signal swing and increased jitter through intersymbol interference (ISI). Controlling the Characteristic Impedance of a TMDS Differential Pair The characteristic impedance of a differential pair depends on a number of variables including the trace width, the distance between the two traces, the height of the dielectric material between the trace and the reference plane below it, and the dielectric constant of the PCB binder material. To a lesser extent, the characteristic impedance also depends upon the trace thickness and the presence of solder mask. Many combinations can produce the correct characteristic impedance. It is generally required to work with the PC board fabricator to obtain a set of parameters to produce the desired results. One consideration is how to guarantee a differential pair with a differential impedance of 100 Ω over the entire length of the trace. One technique to accomplish this is to change the width of the traces in a differential pair based on how closely one trace is coupled to the other. When the two traces of a differential pair are close and strongly coupled, they should have a width that produces a 100 Ω differential impedance. When the traces split apart, for example, to go into a connector, and are no longer so strongly coupled, the width of the traces should be increased to yield a differential impedance of 100 Ω in the new configuration. Ground Current Return In some applications, it may be necessary to invert the output pin order of the ADV3003. This requires routing of the TMDS traces on multiple layers of the PCB. When routing differential pairs on multiple layers, it is also necessary to reroute the corresponding reference plane to provide one continuous ground current return path for the differential signals. Standard plated through-hole vias are acceptable for both the TMDS traces and the reference plane. An example of this routing is illustrated in Figure 27. To lower the impedance between the two ground planes, additional through-hole vias should be used to stitch the planes together, as space allows. THROUGH-HOLE VIAS SILKSCREEN LAYER 1: SIGNAL (MICROSTRIP) PCB DIELECTRIC LAYER 2: GND (REFERENCE PLANE) PCB DIELECTRIC LAYER 3: PWR (REFERENCE PLANE) PCB DIELECTRIC LAYER 4: SIGNAL (MICROSTRIP) SILKSCREEN KEEP REFERENCE PLANE ADJACENT TO SIGNAL ON ALL LAYERS TO PROVIDE CONTINUOUS GROUND CURRENT RETURN PATH. Figure 27. Example Routing of Reference Plane Rev. 0 | Page 13 of 16 07212-027 The ADV3003 buffers the TMDS signals; therefore, the input traces can be considered electrically independent of the output traces. In most applications, the quality of the signal on the input TMDS traces is more sensitive to the PCB layout. Regardless of the data being carried on a specific TMDS channel, or whether the TMDS line is at the input or the output of the ADV3003, all four high speed signals should be routed on a PCB in accordance with the same RF layout guidelines. ADV3003 TMDS Terminations The ADV3003 provides internal 50 Ω single-ended terminations for all its high speed inputs and outputs. The output termination resistors are always enabled and act to back-terminate the output TMDS transmission lines. These back-terminations act to absorb reflections from impedance discontinuities on the output traces, improving the signal integrity of the output traces and adding flexibility to how the output traces can be routed. For example, interlayer vias can be used to route the ADV3003 TMDS outputs on multiple layers of the PCB without severely degrading the quality of the output signal. In a typical application, the ADV3003 output is connected to an HDMI/DVI receiver or another device with a 50 Ω single-ended input termination. It is recommended that the outputs be terminated with external 50 Ω on-board resistors when the ADV3003 is not connected to another device. In a typical application, all pins labeled AVEE, including the ePAD, should be connected directly to ground. All pins labeled AVCC, VTTI, or VTTO should be connected to 3.3 V. The supplies can also be powered individually, but care must be taken to ensure that each stage of the ADV3003 is powered correctly. Power Supply Bypassing The ADV3003 requires minimal supply bypassing. When powering the supplies individually, place a 0.01 μF capacitor between each 3.3 V supply pin (AVCC, VTTI, and VTTO) and ground to filter out supply noise. Generally, bypass capacitors should be placed near the power pins and should connect directly to the relevant supplies (without long intervening traces). For example, to improve the parasitic inductance of the power supply decoupling capacitors, minimize the trace length between capacitor landing pads and the vias as shown in Figure 28. RECOMMENDED Auxiliary Control Signals There are four low-speed, single-ended control signals associated with each source or sink in an HDMI/DVI application. These control signals are hot plug detect (HPD), consumer electronics control (CEC), and two display data channel (DDC) lines. The two signals on the DDC bus are serial data and serial clock (SDA and SCL, respectively). The ADV3003, which is a TMDS-only part, does not buffer these low speed signals. If the end application requires it, use other means to buffer these signals. Power Supplies The ADV3003 has three separate power supplies referenced to a single ground, AVEE. The supply/ground pairs are as follows: AVCC/AVEE, VTTI/AVEE, and VTTO/AVEE. The AVCC/AVEE supply (3.3 V) powers the core of the ADV3003. The VTTI/AVEE supply (3.3 V) powers the input termination (see Figure 25). Similarly, the VTTO/AVEE supply (3.3 V) powers the output termination (see Figure 26). NOT RECOMMENDED 07212-028 EXTRA ADDED INDUCTANCE Figure 28. Recommended Pad Outline for Bypass Capacitors In applications where the ADV3003 is powered by a single 3.3 V supply, it is recommended to use two reference supply planes and bypass the 3.3 V reference plane to the ground reference plane with one 220 pF, one 1000 pF, two 0.01 μF, and one 4.7 μF capacitors. The capacitors should via down directly to the supply planes and be placed within a few centimeters of the ADV3003. Rev. 0 | Page 14 of 16 ADV3003 OUTLINE DIMENSIONS 6.00 BSC SQ 0.60 MAX 0.60 MAX PIN 1 INDICATOR TOP VIEW 0.50 BSC 5.75 BSC SQ 0.50 0.40 0.30 12° MAX 40 1 4.25 4.10 SQ 3.95 EXPOSED PAD (BOT TOM VIEW) 21 20 10 11 0.25 MIN 4.50 REF 0.80 MAX 0.65 TYP 0.05 MAX 0.02 NOM SEATING PLANE 0.30 0.23 0.18 0.20 REF COPLANARITY 0.08 COMPLIANT TO JEDEC STANDARDS MO-220-VJJD-2 *THE ADV3003 HAS A CONDUCTIVE HEAT SLUG (ePAD) TO HELP DISSIPATE HEAT AND ENSURE RELIABLE OPERATION OF THE DEVICE OVER THE FULL HDMI/DVI TEMPERATURE RANGE. THE SLUG IS EXPOSED ON THE BOTTOM OF THE PACKAGE AND ELECTRICALLY CONNECTED TO AVEE. IT IS RECOMMENDED THAT NO PCB SIGNAL TRACES OR VIAS BE LOCATED UNDER THE PACKAGE THAT COULD COME IN CONTACT WITH THE CONDUCTIVE SLUG. ATTACHING THE SLUG TO AN AVEE POWER PLANE REDUCES THE JUNCTION TEMPERATURE OF THE DEVICE WHICH MAY BE BENEFICIAL IN HIGH TEMPERATURE ENVIRONMENTS. 012808-A 1.00 0.85 0.80 PIN 1 INDICATOR 31 30 Figure 29. 40-Lead Lead Frame Chip Scale Package [LFCSP_VQ] 6 mm × 6 mm Body, Very Thin Quad (CP-40-1) Dimensions shown in millimeters ORDERING GUIDE Model ADV3003ACPZ 1 ADV3003ACPZ-R71 ADV3003-EVALZ1 1 Temperature Range −40°C to +85°C −40°C to +85°C Package Description 40-Lead Lead Frame Chip Scale Package [LFCSP_VQ] 40-Lead Lead Frame Chip Scale Package [LFCSP_VQ], Reel 7 Evaluation Board Z = RoHS Compliant Part. Rev. 0 | Page 15 of 16 Package Option CP-40-1 CP-40-1 Ordering Quantity 490 1500 ADV3003 NOTES ©2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07212-0-2/08(0) Rev. 0 | Page 16 of 16