ML6424-1

February 1997 PRELIMINARY ML6424*/ML6425* CCIR601 Video Lowpass Filter with Optional Sinx/x Correction GENERAL DESCRIPTION The ML6424 is a monolithic BiCMOS Video Lowpass Filter IC, incorporating a 5th order Elliptic (Cauer) lowpass filter, a third order allpass filter, and a 75Ω coax cable driver. The ML6425 additionally provides sinx/x amplitude correction. These active lowpass filters are available with a 2.75MHz (-2) or a 5.50MHz (-1) cutoff frequency. The input signal can be either AC or DC coupled under the control of the MODE pin. In the DC coupled case, a control pin (RANGE) is provided to allow the inputs to swing down to ground. Internal self clamping is provided for AC coupled signals. The ML6424 and ML6425 are powered by a single 5V supply, and can drive 1VPP into 75Ω (0.5V to 1.5V), or 2VPP into 150Ω (0.5 to 2.5V). The maximum output swing from 0.5V to 2.5V allows easy interface to the ML6400 family of A/D converters. FEATURES s s s s s s s s s s s s External or internal input clamping with pulse output for synchronous clamping of multiple filters Frequency tunable with REXT: ±10% ±0.25dB ripple >40dB attenuation at f > 1.45 x fC (w/o sinx/x) >35dB attenuation at f > 1.45 x fC (with sinx/x) –12dB attenuation at f = 1.23 x fC Group delay distortion: ±20ns up to 0.9 x fC 1.45 x corner frequency 2T, 0.7VP–P pulse TD(subcarrier) – TD(0); fC = 5.5MHz VOUT P to GND while VOUT M = GND VOUT P to GND RANGE RANGE VIN = GND VIN = VCC Limits are guaranteed by 100% testing, sampling, or correlation with worst case conditions. Digital Inputs: All inputs are high impedance 1µA leakage, with MAX input voltage levels of 0.8V from each supply 4 ML6424/ML6425 FUNCTIONAL DESCRIPTION The ML6424 and ML6425 are monolithic CCIR601 continuous time video filters, designed for broadcast and professional luminance and chrominance antialias and reconstruction applications. They are fabricated using Micro Linear’s 1.5µ, 4 GHz BiCMOS process. The filter incorporates an input amplifier, programmable gain of 1x or 2x set by the GAIN pin, a fifth order lowpass filter, a third order allpass filter, and an output amplifier capable of driving 75Ω to ground. The ML6425 provides sinx/x equalization. The ML6424–1 is intended for application as luminance antialias processing, the ML6424–2 for chrominance antialias, the ML6425–1 for luma reconstruction, and the ML6425–2 for chroma reconstruction. Input signals can be applied either through an AC coupling capacitor (MODE = High/Low) or directly to the input pin (MODE = float). With MODE = High, Y-Channel signal can be applied to the input and the PULSE I/O pin generates a clamping pulse for the U/V channel. When MODE = Low, U/V channel signal can be applied to the input. In this case, the PULSE I/O pin can take the pulse signal generated from the PULSE I/O pin of the other chip in the Y-channel. In the case of direct coupling, RANGE should be adjusted according to the input signal range. When RANGE is low, the input signal range is 0.5V to 1.5V. When the input signal goes down to 0V, RANGE should be tied high. In this case, an offset is added to the input so that the filter can process the 0V DC level. The output amplifier is designed to drive up to 20mA peak into a 75Ω load, or 17mA peak into a 150Ω load. Load resistance less than 75Ω and/or output voltage above 1.5V into 75Ω (2.5V into 150Ω) may cause signal distortion. Good high frequency decoupling is required between each power supply pin and ground, otherwise oscillations and/or excessive crosstalk may occur. 1µF Y 75Ω 6 ML6424-1 VIN P VIN M Y 75Ω 1µF 6 ML6424-1 VIN P VIN M 7 7 +5V 12 MODE +5V 12 MODE 4 PULSE I/O 4 PULSE I/O 1µF U 75Ω 6 ML6424-2 VIN P VIN M U 75Ω 1µF 6 ML6424-2 VIN P VIN M 7 7 12 MODE 12 MODE 4 PULSE I/O 4 PULSE I/O 1µF V 75Ω 6 ML6424-2 VIN P VIN M V 75Ω 1µF 6 ML6424-2 VIN P VIN M 7 7 12 MODE 12 MODE 4 PULSE I/O 4 PULSE I/O Figure 1. YUV Filter with Sync on Y Input and Auto Clamp On Figure 2. YUV Filter with External Sync for U/V 5 ML6424/ML6425 1µF Y 75Ω 6 ML6424-1 VIN P VIN M 7 +5V 12 MODE 4 PULSE I/O 1µF C 75Ω 6 ML6424-2 VIN P VIN M 7 12 MODE 4 PULSE I/O Figure 3. Y/C Filter 6 ML6424/ML6425 ML6424-1 RESPONSE CURVES +10 0 –10 –20 +0.3 +0.2 +0.1 0.0 AMPLITUDE (dB) 1 FREQUENCY (MHz) 10 50 –0.1 –0.2 –0.3 –0.4 –0.5 –0.6 –0.7 100k 3M FREQUENCY (Hz) 6M AMPLITUDE (dB) –30 –40 –50 –60 –70 –80 –90 0.1 Figure 4. Amplitude vs Frequency Figure 5. Amplitude vs Frequency 0˚ 0˚— PHASE (45˚/div) PHASE (10˚/div) 500k FREQUENCY (Hz) 500k FREQUENCY (Hz) 5.5M 5.5M Figure 6. Phase vs Linear Frequency Figure 7. Deviation from Linear Phase 380 360 GROUP DELAY (ns) 340 320 300 280 100k 3M FREQUENCY (Hz) 6M Figure 8. Group Delay vs Frequency 7 ML6424/ML6425 ML6424-2 RESPONSE CURVES +10 0 –10 AMPLITUDE (dB) +0.4 +0.3 +0.2 +0.1 AMPLITUDE (dB) –20 –30 –40 –50 –60 –70 –80 –90 0.1 1 FREQUENCY (MHz) 10 30 0.0 –0.1 –0.2 –0.3 –0.4 –0.5 –0.6 100k 1.5M FREQUENCY (Hz) 3M Figure 9. Amplitude vs Frequency Figure 10. Amplitude vs Frequency 0˚ 0˚ PHASE (45˚/div) PHASE (5˚/div) 200k FREQUENCY (Hz) 200k FREQUENCY (Hz) 2.2M 2.2M Figure 11. Phase vs Linear Frequency Figure 12. Deviation from Linear Phase 730 690 GROUP DELAY (ns) 650 610 570 530 100k 1.5M FREQUENCY (Hz) 3M Figure 13. Group Delay vs Frequency 8 ML6424/ML6425 ML6425-1 RESPONSE CURVES 20 10 0 3.0 RELATIVE AMPLITUDE (dB) +4dB RELATIVE AMPLITUDE (dB) –10 –20 –30 –40 –50 –60 –70 –80 100k 1M FREQUENCY (Hz) 10M 2.0 1.0 0 0.1 1 2 FREQUENCY (MHz) 3 Figure 14. Amplitude vs Frequency Figure 15. Amplitude vs Frequency 0˚ 0˚ PHASE (45˚/div) PHASE (10˚/div) 500k FREQUENCY (Hz) 500k FREQUENCY (Hz) 5.5M 5.5M Figure 16. Phase vs Frequency Figure 17. Deviation from Linear Phase 410 390 370 GROUP DELAY (ns) 350 330 310 290 270 250 230 210 100k 3.5M FREQUENCY (Hz) 6M Figure 18. Group Delay vs Frequency 9 ML6424/ML6425 ML6425-2 RESPONSE CURVES 20 10 0 RELATIVE AMPLITUDE (dB) AMPLITUDE (dB) –10 –20 –30 –40 –50 –60 –70 –80 100k 1M FREQUENCY (Hz) 10M 100k FREQUENCY (Hz) 6.0M 0 3 4 2 1 Figure 19. Amplitude vs Frequency Figure 20. Amplitude vs Frequency 0˚ PHASE (45˚/div) PHASE (5˚/div) 200k FREQUENCY (Hz) 2.2M 200k FREQUENCY (Hz) 2.2M Figure 21. Phase vs Linear Frequency Figure 22. Deviation from Linear vs Phase 630 6 GROUP DELAY (20ns/div) CUT OFF FREQUENCY (Hz) 5 ML6424/25-1 4 3 ML6424/25-2 100k FREQUENCY (Hz) 3.0M 2 8 9 10 REXT (k) 11 12 Figure 23. Group Delay vs Frequency Figure 24. Frequency vs REXT 10 ML6424/ML6425 ML6425-2 RESPONSE CURVES AMPLITUDE (0.5V/div.) INPUT FROM DAC OUTPUT FILTER OUTPUT TIME (500ns/div.) Figure 25. Transient Response 11 ML6424/ML6425 PHYSICAL DIMENSIONS inches (millimeters) Package: S16W 16-Pin Wide SOIC 0.400 - 0.414 (10.16 - 10.52) 16 0.291 - 0.301 0.398 - 0.412 (7.39 - 7.65) (10.11 - 10.47) PIN 1 ID 1 0.024 - 0.034 (0.61 - 0.86) (4 PLACES) 0.050 BSC (1.27 BSC) 0.095 - 0.107 (2.41 - 2.72) 0º - 8º 0.090 - 0.094 (2.28 - 2.39) 0.012 - 0.020 (0.30 - 0.51) SEATING PLANE 0.005 - 0.013 (0.13 - 0.33) 0.022 - 0.042 (0.56 - 1.07) 0.009 - 0.013 (0.22 - 0.33) ORDERING INFORMATION PART NUMBER ML6424-1 ML6424-2 ML6425-1 ML6425-2 FREQ 5.5 2.75 5.5 2.75 SIN X/X NO NO YES YES TEMPERATURE RANGE 0⋅C to 70⋅C 0⋅C to 70⋅C 0⋅C to 70⋅C 0⋅C to 70⋅C PACKAGE 16-Pin SOIC (S16W) (Obsolete) 16-Pin SOIC (S16W) 16-Pin SOIC (S16W) (Obsolete) 16-Pin SOIC (S16W) © Micro Linear 1997 is a registered trademark of Micro Linear Corporation Products described herein may be covered by one or more of the following patents: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761, 5,594,376, 5,592,128. Other patents are pending. Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design. Micro Linear does not assume any liability arising out of the application or use of any product described herein, neither does it convey any license under its patent right nor the rights of others. The circuits contained in this data sheet are offered as possible applications only. Micro Linear makes no warranties or representations as to whether the illustrated circuits infringe any intellectual property rights of others, and will accept no responsibility or liability for use of any application herein. The customer is urged to consult with appropriate legal counsel before deciding on a particular application. 2092 Concourse Drive San Jose, CA 95131 Tel: 408/433-5200 Fax: 408/432-0295 DS6424_25-01 12