6-Channel SD/ED/HD Video Filter with Charge Pump ADA4424-6
FEATURES
3 SD channels; 18 MHz typical 1 dB bandwidth (BW) 3 ED/HD channels; 25 MHz or 34 MHz typical 1 dB BW Fixed gain of 6.2 dB (2.042 V/V) On-board negative supply for output coupling without capacitors Minimal dc offset at the output pins Internal summation of Y and C channels for CVBS output Flexible input dc offset cancellation for luma channels D-terminal (EIAJ RC-5237 D5) and S-terminal (S1/S2) support Capable of driving 2 back-terminated 75 Ω video loads simultaneously Separate power-down pins for SD and ED/HD sections 38-lead TSSOP package Sony Green Partner Environmental Quality Approval Program compliant
FUNCTIONAL BLOCK DIAGRAM
+3.3V VDD3_SD D1 D2 D3 HD_ENB S SD_ENB VDD3_HD +5V VDD5 L1 D/S TERMINAL CONTROL L2 L3 S1/S2 S1/S2_OUT L1_OUT L2_OUT L3_OUT
Y_IN
×1 LPF
×2 ×2
Y_OUT CVBS_OUT C_OUT
C_IN MODE0 MODE1 OFFSET_ENB
×1 LPF OFFSET CANCELLATION FC_SEL
×2
ADA4424-6
HY_IN
×1 LPF FC_SEL
×2
HY_OUT
APPLICATIONS
DVD players and recorders Set-top boxes Projectors Personal video recorders
HPb_IN
×1 LPF FC_SEL
×2
HPb_OUT
HPr_IN FC_SEL SD_ENABLE HD_ENABLE
×1 LPF
×2
HPr_OUT VSS_SD
SD_ENB POWER MANAGEMENT
HD_ENB CHARGE PUMP
VSS_HD
+3.3V
C1
C2
Figure 1.
GENERAL DESCRIPTION
The ADA4424-6 is a high performance video reconstruction filter specifically designed for consumer applications. It consists of a standard definition (SD) section with two fifth-order Butterworth filters and a high definition (HD) section with three fifth-order filters. The SD section contains an internal Y/C summer for CVBS output, whereas the HD section provides selectable corner frequencies for either extended definition (ED) or HD signals. The ADA4424-6 filter/buffer section operates from a single 3.3 V supply. Full support for D-terminal (EIAJ RC-5237 D5) and S1/S2 signaling is provided, along with a dedicated 5 V supply pin. Separate enable pins are provided for the SD and HD sections. The luma channels (Y_IN, HY_IN) of the ADA4424-6 are capable of detecting and cancelling dc input offsets of up to 1.1 V. Four distinct modes of detection/cancellation are available. The output drivers on the ADA4424-6 feature rail-to-rail outputs with 6.2 dB gain. An on-board charge pump allows the outputs to swing up to 1.4 V below ground, eliminating the need for large coupling capacitors. Each output is capable of driving two 75 Ω doubly terminated cables. The ADA4424-6 is available in a 38-lead TSSOP and operates in the industrial temperature range of −40°C to +85°C.
Rev. C
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.
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08550-001
VDD3_CP
C1a
C1b C2/CP_OUT
GND_CP
ADA4424-6 TABLE OF CONTENTS
Features .............................................................................................. 1 Applications ....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 6 Thermal Resistance ...................................................................... 6 Maximum Power Dissipation ..................................................... 6 ESD Caution .................................................................................. 6 Pin Configuration and Function Descriptions ............................. 7 Typical Performance Characteristics ..............................................9 Applications Information .............................................................. 11 CVBS Output .............................................................................. 11 Corner Frequency Selection ..................................................... 11 Input DC Offset Cancellation ................................................... 11 D-Terminal and S-Terminal Support ...................................... 12 Power-Down ............................................................................... 13 Charge Pump .............................................................................. 13 Printed Circuit Board (PCB) Layout ....................................... 13 Outline Dimensions ....................................................................... 15 Ordering Guide .......................................................................... 15
REVISION HISTORY
07/10—Rev. B to Rev. C Change to General Description Section ........................................ 1 05/10—Rev. A to Rev. B Change to Table 1, Overall Performance ....................................... 3 Change to Ordering Guide ............................................................ 15 12/09—Rev. 0 to Rev. A Changes to Table 1 ............................................................................ 4 Changes to Table 2 ............................................................................ 5 Changes to Table 5 .......................................................................... 10 Changes to Table 8 to Table 11...................................................... 11 Change to Table 12 and Table 13 .................................................. 12 10/09—Revision 0: Initial Version
Rev. C | Page 2 of 16
ADA4424-6 SPECIFICATIONS
VDD3 = 3.3 V, TA = 25°C, VO = 2.042 V p-p, RL = 150 Ω, dc-coupled outputs, unless otherwise noted. Charge pump configured as shown in Figure 18. Table 1.
Parameter OVERALL PERFORMANCE DC Voltage Gain Input Voltage Range, All Inputs Output Voltage Range, All Outputs Input Bias Current Input Impedance Output Resistance Test Conditions/Comments All channels Not including dc offset Y_IN, HY_IN, dc-coupled C_IN, HPb_IN, HPr_IN, ac-coupled Y_OUT, C_OUT, CVBS_OUT, HY_OUT, HPb_OUT, HPr_OUT, dc-coupled L1_OUT, L2_OUT, L3_OUT, S1/S2_OUT, dc-coupled f = 100 kHz to 6.75 MHz f = 148.5 MHz f = 1 MHz f = 1 MHz, VO = 1.4 V p-p f = 100 kHz to 6 MHz, unweighted f = 100 kHz to 5 MHz NTSC NTSC FC_SEL = low (0) f = 100 kHz to 13.5 MHz f = 148.5 MHz f = 1 MHz f = 5 MHz, VO = 1.4 V p-p f = 100 kHz to 13.5 MHz, unweighted f = 100 kHz to 13.5 MHz FC_SEL = high (1) f = 100 kHz to 30 MHz Y Channel (HY_OUT) P Channels (HPb_OUT, HPr_OUT) f = 148.5 MHz f = 1 MHz f = 10 MHz, VO = 1.4 V p-p f = 100 kHz to 30 MHz, unweighted f = 100 kHz to 30 MHz 14 38 Min 6.0 Typ 6.2 −0.6 to +1.4 −1.6 to +3.0 30 800 0.5 10.5 0.00 18 42 67 0.07 68 1 0.2 0.5 0.02 25 42 65 0.45 66 1.5 0.1 39 34 37 65 1.2 65 2.2 3.14 to 3.46 93 54 45 6.1 4.75 to 5.25 0.01 Max 6.4 Unit dB V V pA kΩ Ω kΩ dB MHz dB dB % dB ns % Degrees dB MHz dB dB % dB ns dB MHz MHz dB dB % dB ns V mA mA mA mA V
SD CHANNEL DYNAMIC PERFORMANCE In-Band Peaking 1 dB Bandwidth Out-of-Band Rejection Crosstalk Total Harmonic Distortion Signal-to-Noise Ratio Group Delay Variation Differential Gain Differential Phase ED CHANNEL DYNAMIC PERFORMANCE In-Band Peaking 1 dB Bandwidth Out-of-Band Rejection Crosstalk Total Harmonic Distortion Signal-to-Noise Ratio Group Delay Variation HD CHANNEL DYNAMIC PERFORMANCE In-Band Peaking 1 dB Bandwidth Out-of-Band Rejection Crosstalk Total Harmonic Distortion Signal-to-Noise Ratio Group Delay Variation DC CHARACTERISTICS Operating Voltage, 3.3 V Supply Quiescent Supply Current, 3.3 V Supply
0.1
21 38
0.2
30 25 33
Both active, SD_ENABLE = high, HD_ENABLE = high, no load, no signal, not including D/S terminal outputs SD disabled, SD_ENABLE = low, HD_ENABLE = high HD disabled, SD_ENABLE = high, HD_ENABLE = low Both disabled, SD_ENABLE = low, HD_ENABLE = low
133
10
Operating Voltage, 5 V Supply
Rev. C | Page 3 of 16
ADA4424-6
Parameter Quiescent Supply Current, 5 V Supply Test Conditions/Comments SD_ENABLE = high, HD_ENABLE = high, RL = 100 kΩ, D1, D2, D3 = high, S = high SD_ENABLE = low, HD_ENABLE = low ED/HD channels, output referred SD channels, output referred See Table 6 and Table 7 OFFSET_ENB = low Y_IN = 0 V dc Y_IN = 0 V dc HY_IN = 0 V dc OFFSET_ENB = high, MODE1 = high Y_IN = 1.0 V dc, MODE0 = low HY_IN = 1.1 V dc, MODE0 = low Y_IN = 0.33 V dc, MODE0 = high HY_IN = 0.33 V dc, MODE0 = high OFFSET_ENB = high, MODE1 = low Y_IN = 0 V to 1.0 V dc, MODE0 = low HY_IN = 0 V to 1.1 V dc, MODE0 = low Y_IN = 0 V to 1.0 V dc, MODE0 = high HY_IN = 0 V to 1.1 V dc, MODE0 = high Min Typ 190 5 −42 −41 Max 200 15 Unit μA μA dB dB
PSRR DC Offset Input Referred, Offset Cancellation Disabled Mode SD Channels CVBS Channel ED/HD Channels Input Referred, Fixed Offset Cancellation Mode SD Fixed High Offset Mode ED/HD Fixed High Offset Mode SD Fixed Low Offset Mode ED/HD Fixed Low Offset Mode Input Referred, Auto Offset Cancellation Mode SD Auto Offset Mode Sync Tip Sampling ED/HD Auto Offset Mode Sync Tip Sampling SD Auto Offset Mode Back Porch Sampling ED/HD Auto Offset Mode Back Porch Sampling FC_SEL Input Logic Low Level FC_SEL Input Logic High Level xD_ENABLE, OFFSET_ENB, MODEx Input Logic Low Level xD_ENABLE, OFFSET_ENB, MODEx Input Logic High Level xD_ENABLE Assert Time xD_ENABLE Deassert Time xD_ENABLE Input Bias Current Input-to-Output Isolation D- and S-Terminal Input Logic Low Level D- and S-Terminal Input Logic Mid Level D- and S-Terminal Input Logic High Level D- and S-Terminal Input Logic Open (Hi-Z) Resistance Value D-Terminal (L1_OUT, L2_OUT, L3_OUT) Low Level Output D-Terminal (L1_OUT, L3_OUT) Mid Level Output D-Terminal (L1_OUT, L2_OUT, L3_OUT) High Level Output S-Terminal (S1/S2_OUT) Low Level Output
−60 −100 −60
−20 −40 −20
+60 +100 +60
mV mV mV
−100 −100 −90 −100
−30 −38 −17 −25
+100 +100 +90 +100
mV mV mV mV
−70 −95 −25 −25 0 1.2 0 2.0
−36 −46 −6 −5
+70 +95 +25 +25 0.6 VDD3 0.8 VDD3
mV mV mV mV V V V V ns ns μA dB V V V kΩ
xD_ENABLE = low to high xD_ENABLE = high to low Disabled, xD_ENABLE = low Disabled, xD_ENABLE = low, f = 5 MHz RL = 100 kΩ RL = 100 kΩ RL = 100 kΩ RL = 100 kΩ VDD5 = 5.0 V, RL = 100 kΩ, D1, D2, D3 = low VDD5 = 5.0 V, RL = 100 kΩ, D1, D3 = mid or open VDD5 = 5.0 V, RL = 100 kΩ, D1, D2, D3 = high VDD5 = 5.0 V, RL = 100 kΩ, S = low
95 20 6.1 −100 0 0.9 2.7 200 0.0 2.1 4.5 0.0 0.6 1.9 VDD3
V V V V
Rev. C | Page 4 of 16
ADA4424-6
Parameter S-Terminal (S1/S2_OUT) Mid Level Output S-Terminal (S1/S2_OUT) High Level Output CHARGE PUMP CHARACTERISTICS Output Voltage Output Voltage Ripple Output Ripple Frequency Test Conditions/Comments VDD5 = 5.0 V, RL = 100 kΩ, S = mid or open VDD5 = 5.0 V, RL = 100 kΩ, S = high All channels operating; C1 = C2 = 4.7 μF, C3 = C4 = 1.0 μF, R1 = 1 Ω (see Figure 18) −1.66 180 100 V mV p-p kHz Min Typ 2.1 4.5 Max Unit V V
Rev. C | Page 5 of 16
ADA4424-6 ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter 3.3 V Supply Voltage 5 V Supply Voltage Digital Input Voltage (Pin 2 to Pin 5, Pin 8, Pin 12, Pin 15, Pin 16, Pin 23) Power Dissipation Storage Temperature Range Operating Temperature Range Lead Temperature (Soldering, 10 sec) Junction Temperature Rating 3.6 V 5.5 V 3.6 V See Figure 2 −65°C to +125°C −40°C to +85°C 300°C 150°C
The power dissipated in the package (PD) is the sum of the quiescent power dissipation and the power dissipated in the package due to the load drive for all outputs. The quiescent power is the voltage between the supply pins (VS) times the quiescent current (IS). The power dissipated due to load drive depends on the particular application. For each output, the power due to load drive is calculated by multiplying the load current by the associated voltage drop across the device. The power dissipated due to the loads is equal to the sum of the power dissipations due to each individual load. RMS voltages and currents must be used in these calculations. Airflow increases heat dissipation, effectively reducing θJA. Figure 2 shows the maximum power dissipation in the package vs. the ambient temperature for the 38-lead TSSOP (67.6°C/W) on a JEDEC standard 4-layer board. θJA values are approximate.
2.4 2.2
MAXIMUM POWER DISSIPATION (W)
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.
2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 10 20 30 40 50 60 70 80 90 100
08550-002
THERMAL RESISTANCE
θJA is specified for the device soldered to a high thermal conductivity 4-layer (2s2p) circuit board, as described in EIA/JESD 51-7. Table 3.
Package Type 38-Lead TSSOP θJA 67.6 θJC 14.0 Unit °C/W
0
MAXIMUM POWER DISSIPATION
The maximum safe power dissipation in the ADA4424-6 package is limited by the associated rise in junction temperature (TJ) on the die. At approximately 150°C, which is the glass transition temperature, the plastic changes its properties. Even temporarily exceeding this temperature limit can change the stresses that the package exerts on the die, permanently shifting the parametric performance of the ADA4424-6. Exceeding a junction temperature of 150°C for an extended time can result in changes in the silicon devices, potentially causing failure.
AMBIENT TEMPERATURE (°C)
Figure 2. Maximum Power Dissipation vs. Ambient Temperature for a 4-Layer Board
ESD CAUTION
Rev. C | Page 6 of 16
ADA4424-6 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
GND5 D1 D2 D3 S Y_IN VDD3_SD SD_ENABLE C_IN
1 2 3 4 5 6 7 8 9 38 37 36 35 34 33
VDD5 L1_OUT L2_OUT L3_OUT S1/S2_OUT Y_OUT VSS_SD CVBS_OUT C_OUT GND3 HY_OUT VSS_HD HPb_OUT HPr_OUT VDD3_HD MODE1 C2/CP_OUT GND_CP
08550-003
ADA4424-6
TOP VIEW (Not to Scale)
32 31 30 29 28 27 26 25 24 23 22 21 20
GND3 10 HY_IN 11 FC_SEL 12 HPb_IN 13 HPr_IN 14 HD_ENABLE 15 MODE0 16 OFFSET_ENB 17 VDD3_CP 18 C1a 19
C1b
Figure 3. Pin Configuration, Top View
Table 4. Pin Function Descriptions
Pin No. 1 2 3 4 5 6 7 8 9 10, 29 11 12 13 14 15 16 17 18 19, 21 20 22 23 24 25 26 27 28 30 31 Mnemonic GND5 D1 D2 D3 S Y_IN VDD3_SD SD_ENABLE C_IN GND3 HY_IN FC_SEL HPb_IN HPr_IN HD_ENABLE MODE0 OFFSET_ENB VDD3_CP C1a, C1b GND_CP C2/CP_OUT MODE1 VDD3_HD HPr_OUT HPb_OUT VSS_HD HY_OUT C_OUT CVBS_OUT Description Ground Pin for 5 V Supply. D-Terminal Vertical Resolution Selection Input. D-Terminal Scan Selection Input. D-Terminal Aspect Ratio Selection Input. S-Terminal Aspect Ratio Selection Input. SD Luma (Y) Input. 3.3 V Supply Pin for SD Filter Section. Output Enable Pin for SD (Y, C, CVBS). SD Chroma (C) Input. Ground Pins for 3.3 V Supply. ED/HD Y Component Input. Filter Corner Frequency Selection Pin for HY, HPb, HPr Channels. ED/HD Pb Component Input. ED/HD Pr Component Input. Output Enable Pin for ED/HD (HY, HPb, HPr). This pin selects sync tip or back porch sampling when MODE1 = 0 and selects high or low fixed offset subtraction when MODE1 = 1. Offset Cancellation Enable Pin. 3.3 V Supply Pins for Charge Pump Section. Charge Pump Capacitor C1 Connection Pin. Ground Pin for 3.3 V Charge Pump Supply. Charge Pump Output Pin. Connect Capacitor C2 from this pin to ground. Selects Automatic or Fixed Offset Subtraction Mode. 3.3 V Supply Pin for ED/HD Filter Section. ED/HD Pr Component Output. ED/HD Pb Component Output. Negative Supply Pin for ED/HD Filter Section. This pin should be connected to the charge pump output (Pin 22), as shown in Figure 18. ED/HD Y Component Output. SD Chroma (C) Output. SD Composite Video (CVBS) Output.
Rev. C | Page 7 of 16
ADA4424-6
Pin No. 32 33 34 35 36 37 38 Mnemonic VSS_SD Y_OUT S1/S2_OUT L3_OUT L2_OUT L1_OUT VDD5 Description Negative Supply Pin for SD Filter Section. This pin should be connected to the charge pump output (Pin 22), as shown in Figure 18. SD Luma (Y) Output. S-Terminal Aspect Ratio Selection Output. D-Terminal Aspect Ratio Selection Output. D-Terminal Scan Selection Output. D-Terminal Vertical Resolution Selection Output. 5 V Supply Pin for D-Terminal and S-Terminal Signaling.
Rev. C | Page 8 of 16
ADA4424-6 TYPICAL PERFORMANCE CHARACTERISTICS
VDD3 = 3.3 V, TA = 25°C, VO = 2.042 V p-p, RL = 150 Ω, dc-coupled outputs, unless otherwise noted. Charge pump configured as shown in Figure 18.
10 0 0.5
NORMALIZED GAIN (dB)
–10
NORMALIZED GAIN (dB)
0 C Y/CVBS
–20
–30 –40 C –50 CVBS
08550-004
–0.5
Y
1
10 FREQUENCY (MHz)
100
1
10 FREQUENCY (MHz)
100
Figure 4. Frequency Response—SD Channels
10 0 0.5
Figure 7. Frequency Response Peaking—SD Channels
NORMALIZED GAIN (dB)
NORMALIZED GAIN (dB)
–10
0 Pr
HY
Pb
–20
–30 –40 HY –50 –60 0.1 Pr Pb
–0.5
08550-005
1
10 FREQUENCY (MHz)
100
1k
1
10 FREQUENCY (MHz)
100
Figure 5. Frequency Response—ED Channels
10 0 0.5
Figure 8. Frequency Response Peaking—ED Channels
NORMALIZED GAIN (dB)
–10
NORMALIZED GAIN (dB)
HY 0 Pb/Pr
–20
–30 –40 Pr Pb –50 –60 0.1 HY
–0.5
08550-006
1
10 FREQUENCY (MHz)
100
1k
1
10 FREQUENCY (MHz)
100
Figure 6. Frequency Response—HD Channels
Figure 9. Frequency Response Peaking—HD Channels
Rev. C | Page 9 of 16
08550-009
–1.0 0.1
08550-008
–1.0 0.1
08550-007
–60 0.1
–1.0 0.1
ADA4424-6
–20 ALL HOSTILE REFERRED TO INPUT –30 –30 –20 ALL HOSTILE REFERRED TO INPUT
CROSSTALK (dB)
–50
CROSSTALK (dB)
–40
–40
–50
–60
C_OUT Y_OUT
–60
HPb_OUT, HPr_OUT
–70 CVBS_OUT
08550-010
–70 HY_OUT
1
10 FREQUENCY (MHz)
100
1
10 FREQUENCY (MHz)
100
Figure 10. Crosstalk—SD Channels
45 40 35 45 40 35
Figure 13. Crosstalk—ED and HD Channels
GROUP DELAY (ns)
30 25 20 15 10 5
GROUP DELAY (ns)
CVBS_OUT
30 25 20 15 10 5
Y_OUT, C_OUT
08550-011
1
10 FREQUENCY (MHz)
100
1
10 FREQUENCY (MHz)
100
Figure 11. Group Delay—SD Channels
45 40 35 –40 –50 –60 –70 –80 –90 –100 –110 –120 0.1
Figure 14. Group Delay—ED Channels
30 25 20 15 10 5
08550-012
1
10 FREQUENCY (MHz)
100
1
10 FREQUENCY (MHz)
100
Figure 12. Group Delay—HD Channels
Figure 15. Input-to-Output Isolation—All Channels
Rev. C | Page 10 of 16
08550-015
0 0.1
INPUT-TO-OUTPUT ISOLATION (dB)
VIN = 1.0V p-p RL = 150Ω SD_ENABLE = 0 HD_ENABLE = 0
GROUP DELAY (ns)
08550-014
0 0.1
0 0.1
08550-013
–80 0.1
–80 0.1
ADA4424-6 APPLICATIONS INFORMATION
CVBS OUTPUT
The composite video signal (CVBS_OUT) is produced by passively summing the Y and C channels (see Figure 1), after amplification by their respective gain stages. Each signal experiences a 6.2 dB loss from the passive summation and is subsequently amplified by 6.2 dB in the fixed stage following the summer. The net signal gain through the composite video path is, therefore, 0 dB, and the resulting composite signal present at the ADA4424-6 output is the sum of Y and C with unity gain.
BLACK LEVEL BACK PORCH SAMPLE INTERVAL
CORNER FREQUENCY SELECTION
The component channels of the ADA4424-6 allow for a 1 dB filter corner frequency of either 25 MHz or 39 MHz/34 MHz. The FC_SEL pin operates as described in Table 5. Table 5. ED/HD Bandwidth Selection
FC_SEL (Pin 12) Low (0) High (1) HD/ED ED HD −1 dB Corner Frequency (Typ) 25 MHz 39 MHz (HY); 34 MHz (Pb, Pr)
SYNC TIP SAMPLE INTERVAL
08550-017
08550-018
Figure 16. Back Porch and Sync Tip Sample Intervals (SD/ED)
INPUT DC OFFSET CANCELLATION
The luma channels (Y_IN, HY_IN) of the ADA4424-6 are capable of detecting and cancelling dc input offsets of up to 1.1 V. Four distinct modes of detection/cancellation are available. These are selected via the MODE1 and MODE0 pins. The chroma (C_IN) and color difference (HPb_IN, HPr_IN) inputs do not support offset cancellation. It is recommended that these inputs be accoupled.
BLACK LEVEL BACK PORCH SAMPLE INTERVAL
Automatic Detection/Cancellation Mode
There are two modes of automatic operation. The primary mode samples the input signal between the rising edge of the horizontal sync pulse and the start of active video (back porch), averages the value over the sampling interval, and subtracts it from the output signal. This is the more accurate method and is able to reduce the input-referred offsets to less than 25 mV. An alternate method is available for copy-protected signals, where sampling the back porch may not provide a reliable dc average. This method detects the input negative sync tip, and clamps it to a fixed value (−214 mV for SD, and −300 mV for ED/HD). Sample intervals for SD and ED are shown in Figure 16, and the HD sample intervals are shown in Figure 17.
SYNC TIP SAMPLE INTERVAL
Figure 17. Back Porch and Sync Tip Sample Intervals (HD)
Rev. C | Page 11 of 16
ADA4424-6
Fixed Offset Cancellation Mode
In addition to the automatic mode, there are two levels of fixed offset correction available. In high offset mode, fixed voltages of 1.0 V and 1.1 V are subtracted from the Y_IN and HY_IN inputs, respectively. In low offset mode, a fixed voltage of 0.33 V is subtracted from both Y_IN and HY_IN. The various modes of offset cancellation are outlined in Table 6. Table 6. Offset Cancellation Mode Selection
MODE1 (Pin 23) Low (0) MODE0 (Pin 16) Low (0) Output Offset Cancellation Auto-cancel, sync-tip sampling mode. Clamps the input referred SD sync tip to −214 mV, and the input referred ED/HD sync tip to −300 mV. Auto-cancel, back porch sampling mode. Sets the output blanking level to 0 V, independent of sync depth. Fixed cancellation mode, high dc offset. Subtracts 1.0 V from the Y_IN signal; subtracts 1.1 V from the HY_IN signal. Fixed cancellation mode, low dc offset. Subtracts 0.33 V from both the Y_IN and HY_IN signals.
D-TERMINAL AND S-TERMINAL SUPPORT
Full D-terminal support (EIAJ RC-5237 D5) is provided for the component channels (HY_OUT, HPb_OUT, HPr_OUT). Level D1 through Level D5 are supported for vertical resolution, scan type, and aspect ratio selection. Details are shown in Table 8, Table 9, and Table 10. S-terminal (also known as S_DC or S1/S2) support for S-video aspect ratio selection is also provided, as described in Table 11. The VDD5 pin (Pin 38) provides 5 V power for these outputs. If D- or S-terminal support is not required, it is recommended that Pin 2 to Pin 5 and Pin 34 to Pin 38 remain unconnected. Table 8. D-Terminal Control for Vertical Resolution Selection
Input Logic Level D1 (Pin 2) Low (0) Mid or open High (1) Nominal Output (V) L1_OUT (Pin 37) RL = 100 kΩ 0.0 2.1 4.5 Vertical Resolution (Number of Lines) 480 720 1080
Low (0)
High (1)
High (1)
Low (0)
High (1)
High (1)
Table 9. D-Terminal Control for Scan Selection
Input Logic Level D2 (Pin 3) Low (0) Mid or open High (1) Nominal Output (V) L2_OUT (Pin 36) RL = 100 kΩ 0.0 2.1 4.5
Offset Cancellation Disable
The offset cancellation function can be enabled or disabled via the OFFSET_ENB pin, as described in Table 7. Table 7. Offset Cancellation Enable/Disable
OFFSET_ENB (Pin 17) Low (0) High (1) Offset Cancellation State Offset cancellation is disabled. Offset cancellation is enabled. Function is determined by the MODE1 and MODE0 pins (see Table 6).
Scan Type Interlaced N/A Progressive
Table 10. D-Terminal Control for Aspect Ratio Selection
Input Logic Level D3 (Pin 4) Low (0) Mid or open High (1) Nominal Output (V) L3_OUT (Pin 35) RL = 100 kΩ 0.0 2.1 4.5
Aspect Ratio 4:3 4:3 letterbox 16:9
Table 11. S-Terminal Control for Aspect Ratio Selection
Input Logic Level S (Pin 5) Low (0) Mid or open High (1) Nominal Output (V) S1/S2_OUT (Pin 34) RL = 100 kΩ 0.0 2.1 4.5
Aspect Ratio 4:3 4:3 letterbox 16:9
Rev. C | Page 12 of 16
ADA4424-6
POWER-DOWN
The ADA4424-6 provides separate output enable pins for the SD and ED/HD sections. In addition to powering down the Y, C, and CVBS outputs, the SD_ENABLE pin, when driven low, also places the S1/S2 output (S1/S2_OUT, Pin 34) in a high impedance state. Likewise, driving the HD_ENABLE pin low disables the component outputs (HY_OUT, HPb_OUT, and HPr_OUT) and changes the L1, L2, and L3 outputs (Lx_OUT, Pin 35 to Pin 37) to a high impedance state. Control details are shown in Table 12 and Table 13. Table 12. Power-Down Control for SD Channels
SD_ENABLE (Pin 8) Low (0) High (1) SD Outputs (Y, C, CVBS) Disabled Enabled S1/S2_OUT (Pin 34) High-Z (Open) Active
CHARGE PUMP
The ADA4424-6 features an on-chip charge pump that supplies a negative rail voltage for the output stages. To minimize internal noise coupling, the charge pump uses an external connection to the negative supply pins (VSS_SD and VSS_HD). These pins should be connected to the C2/CP_OUT pin, each decoupled with a 1.0 μF capacitor. It is also recommended to place a small (1 Ω) series resistor in this connection. This forms a low-pass filter with the VSS decoupling capacitors and further reduces coupled noise. The charge pump also requires two 4.7 μF ceramic capacitors, one connected across the C1a and C1b pins, and one connected from the C2/CP_OUT pin to ground. The recommended charge pump configuration is shown in the application diagram (Figure 18). With the black or zero level of the outputs placed at approximately ground potential, the outputs can swing up to 1.6 V in the negative direction. This eliminates the need for large output coupling capacitors because the input-referred dc offsets does not exceed ±100 mV (depending on the selected cancellation mode).
Table 13. Power-Down Control for ED/HD Channels
HD_ENABLE (Pin 15) Low (0) High (1) ED/HD Outputs (HY, HPb, HPr) Disabled Enabled Lx_OUT (Pin 35, Pin 36, Pin 37) High-Z (Open) Active
PRINTED CIRCUIT BOARD (PCB) LAYOUT
As with all high speed applications, attention to the PCB layout is of paramount importance. When designing with the ADA4424-6, adhere to standard high speed layout practices. A solid ground plane is recommended, and surface-mount, ceramic power supply decoupling capacitors should be placed as close as possible to the supply pins. Connect all of the ADA4424-6 GND pins to the ground plane with traces that are as short as possible. Controlled impedance traces of the shortest length possible should be used to connect to the signal I/O pins and should not pass over any voids in the ground plane. A 75 Ω impedance level is typically used in video applications. When driving transmission lines, include series termination resistors on the signal outputs of the ADA4424-6.
Rev. C | Page 13 of 16
ADA4424-6
+3.3V + OFFSET_ENB MODE0 MODE1 Y_IN DAC1
10µF
ADA4424-6
VIDEO ENCODER
x1 LPF
x2 x2
Y_OUT 75Ω CVBS_OUT 75Ω C_OUT GND3 VSS_SD C3 1.0µF 75Ω CVBS S-VIDEO
100nF DAC2
C_IN
x1 LPF
x2
SD_ENABLE VDD3_SD 1.0µF HY_IN
DAC3
x1 LPF
x2 HY_OUT HPb_OUT 75Ω HPr_OUT GND3 VSS_HD C4 1.0µF CHARGE PUMP 75Ω 75Ω
Y
DAC4 1.0µF
HPb_IN
x1 LPF
x2
Pb
DAC5 1.0µF RSET1 RSET2
HPr_IN FC_SEL HD_ENABLE VDD3_HD 1.0µF VDD3_CP 1.0µF
x1 LPF
x2
Pr
C1a C1 4.7µF +3.3V
C1b GND_CP C2 4.7µF
C2/CP_OUT R1 1.0Ω
08550-019
Figure 18. Typical Application Diagram for Using the ADA4424-6 in Auto Offset Cancellation Mode (D and S Terminal Connections Not Shown)
Rev. C | Page 14 of 16
ADA4424-6 OUTLINE DIMENSIONS
9.80 9.70 9.60
38
20
4.50 4.40 4.30 6.40 BSC
1 19
PIN 1 1.20 MAX 8° 0°
0.15 0.05 COPLANARITY 0.10 0.50 BSC 0.27 0.17
SEATING PLANE
0.20 0.09
0.70 0.60 0.45
COMPLIANT TO JEDEC STANDARDS MO-153-BD-1
Figure 19. 38-Lead Thin Shrink Small Outline Package [TSSOP] (RU-38) Dimensions shown in millimeters
ORDERING GUIDE
Model 1 ADA4424-6ARUZ ADA4424-6ARUZ-R7 ADA4424-6ARUZ-RL
1
Temperature Range −40°C to +85°C −40°C to +85°C −40°C to +85°C
Package Description 38-Lead Thin Shrink Small Outline Package (TSSOP) 38-Lead Thin Shrink Small Outline Package (TSSOP) 38-Lead Thin Shrink Small Outline Package (TSSOP)
Package Option RU-38 RU-38 RU-38
Ordering Quantity 50 1,000 2,500
Z = RoHS Compliant Part.
Rev. C | Page 15 of 16
ADA4424-6 NOTES
©2009-2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08550-0-7/10(C)
Rev. C | Page 16 of 16