February 1997 PRELIMINARY ML6424*/ML6425* CCIR601 Video Lowpass Filter with Optional Sinx/x Correction GENERAL DESCRIPTION FEATURES 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. ■ External or internal input clamping with pulse output for synchronous clamping of multiple filters ■ 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. ■ 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% peak overshoot and ringing on 2T test pulse 0.5% diff. gain and 0.5⋅ diff. phase typical THD <1% at 3.58 or 4.43MHz Programmable input-output gain of 1x or 2x 5V ±5% operation *Some packages Are Obsolete ■ ■ ■ ■ ■ ■ 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. ■ ■ ■ BLOCK DIAGRAM +5V GAIN 13 VIN P VIN M 6 INPUT CLAMP + – 7 BUF VCC VCC 5 5TH ORDER LOW PASS MODE 12 PULSE 4 I/O VCC 3 1 3RD ORDER ALL PASS + BUF – SINX/X 15 VOUT P 16 VOUT M FILTER BIAS PULSE CONTROL 8 RANGE Bandwidth Sinx/x VCC 11 ML6424-1 5.50MHz No 9 10 REXT 10kΩ 1% ML6424-2 2.75MHz No 14 GND GND 2 GND ML6425-1 5.50MHz Yes ML6425-2 2.75MHz Yes 1 ML6424/ML6425 PIN CONFIGURATION Package: S16W 16-Pin SOIC VCC 1 16 VOUT M GND 2 15 VOUT P VCC 3 14 GND PULSE I/O 4 13 GAIN VCC 5 12 MODE VIN P 6 11 VCC VIN M 7 10 GND RANGE 8 9 REXT TOP VIEW 2 ML6424/ML6425 PIN DESCRIPTION Pin # Name Description Pin # Name Description 1,3, 5,11 VCC Positive supply voltages (4.75V to 5.25V). 12 MODE 2,10, 14 GND Ground voltages. 4 PULSE I/O U/V clamp switch control input/output pin. When MODE is low, U/V clamp control pulse can be applied to this input pin. When MODE is high, the internal circuit generates a U/V clamp control signal to produce an output pulse at this pin. When MODE is floating, do not apply any voltage to this pin since it is internally tied low in this case. (See table below) Input coupling mode control pin. When MODE is low, U/V signal can be applied through an external ac coupling capacitor to VIN P. When MODE is high, Y signal can be applied through an external AC coupling capacitor to VIN P. In this case, an internal circuitry clamps the sinc tip of the video input signal. When MODE is set to mid supply or left floating, input signal can be directly applied to the input without an AC coupling capacitor. 13 GAIN Three state gain control pin. GAIN tied low sets the input amplifier gain to 3/4 (0.75) and the output amplifier gain to 4/3 (1.333). When GAIN is tied high, the input amplifier gain is 3/2 (1.5) and the output amplifier gain is 4/3. When GAIN is set to mid supply or left to float, the input amplifier gain is 3/4 and the output gain is 8/3 (2.666). (See table below) 15,16 VOUT P, VOUT M The output from the filter is derived from the VOUT P pin with respect to the VOUT M pin which is grounded typically. It can drive 1VPP/75Ω (0.5V to 1.5V) or 2VPP/150Ω (0.5V to 2.5V). If the ouput common-mode level needs to be increased, it can be done by raising the potential of VOUT M. In this case, the output is measured from VOUT P with respect to GND. 6,7 VIN P, VIN M Input to the filter. The input voltage for the filter is applied to VIN P pin with respect to VIN M pin which is grounded. (With no connection to MODE pin, input signal range should be from VIN = 0.5V to 1.5V when RANGE = Low, VIN = 0V to 1V when RANGE = High). There is a 100µA internal current source connected to each of these inputs. 8 RANGE Input signal range control when MODE is floating. When RANGE is low, the input signal range is 0.5V to 1.5V, when RANGE is tied high the input signal range is 0V to 1V. 9 REXT Precision resistor to ground that defines the cutoff frequency of the filter. (Typical value = 10kΩ) 10% change in REXT produces a 10% change in fC (Fig. 28). GAIN INPUT INPUT SELECT BUFFER GAIN OUTPUT BUFFER GAIN OUTPUT OPTIMIZES MODE INPUT COUPLING PULSE Low AC for U/V Input Float DC Internally biased Low 1VPP 0.75 1.333 1VPP — High AC for Y Output Float 1VPP 0.75 2.666 2VPP Differential Phase & Gain High 1VPP 1.50 1.333 2VPP Noise Pulse Mode Table Gain Table 3 ML6424/ML6425 ABSOLUTE MAXIMUM RATINGS OPERATING CONDITIONS Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. Operating temperature range ......................... 0°C to 70⋅C Operating supply range ....................................... 5V ±5% DC Supply Voltage ........................................ –0.3V to 7V Analog & Digital Inputs/Outputs ................................. –0.3V to VCC + 0.3V Input current per pin .............................. –25mA to 25mA Storage Temperature ................................ –65°C to 150⋅C Maximum Junction Temperature ............................ 150⋅C ELECTRICAL CHARACTERISTICS Unless otherwise specified, VCC = 4.75 to 5.25V, TA = Operating Temperature Range (Note 1). PARAMETER CONDITIONS MIN Supply Current MAX UNITS 100 150 mA 100 120 µA 3.0 5 % 0.0 0.2 dB 0.25 dB Input Current (VIN P, VIN M) Sourcing out of the device Input Current Matching Between VIN P and VIN M (tied to GND) Low Frequency Gain VIN = 100mVP–P @ 100kHz –0.2 Passband Ripple 100Hz < fIN < fC –0.25 Differential Gain (RANGE = High) VIN: 1.0V ± 0.5V, @ 3.58 or 4.43MHz 0.5 1 % Differential Phase (RANGE = High) VIN: 1.0V ± 0.5V, @ 3.58 or 4.43MHz 0.5 1 Degree 0.5 1.5 V 0 1 V Dynamic Input Signal Range (MODE = Float) RANGE = Low RANGE = High Output Noise (GAIN = High) Corner Frequency (fC) (±0.25dB) 80 TYP Bw: 30MHz, ML6424-1 1.7 2.3 mVRMS Bw: 30MHz, ML6424-2 1.3 1.9 mVRMS Bw: 30MHz, ML6425-1 1.7 2.3 mVRMS Bw: 30MHz, ML6425-2 1.3 1.9 mVRMS ML6424-1 or ML6425-1 5.23 5.50 5.78 MHz ML6424-2 or ML6424-2 2.61 2.75 2.89 MHz Stopband Loss (ML6424-1, -2) fIN > 1.45 x corner frequency 35 38 dB Stopband Loss (ML6425-1, -2) fIN > 1.45 x corner frequency 30 33 dB Peak Overshoot and Ringing 2T, 0.7VP–P pulse 1 % Composite Chroma/Luma Delay TD(subcarrier) – TD(0); fC = 5.5MHz 20 ns Output Short Circuit Current VOUT P to GND while VOUT M = GND 45 mA Load Capacitance VOUT P to GND 35 pF Logic Input Low (VIL) RANGE Logic Input High (VIH) RANGE Logic Input Low (IIL) VIN = GND Logic Input High (IIL) VIN = VCC Note 1: Note 2: 4 0.8 V VCC – 0.8 V –1 µA 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 1 µA 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. 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 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. 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. 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 Good high frequency decoupling is required between each power supply pin and ground, otherwise oscillations and/or excessive crosstalk may occur. ML6424-1 1µF Y 75Ω 6 VIN P 7 VIN M Y 75Ω U 75Ω 6 VIN P 7 VIN M U 75Ω V 75Ω VIN P 7 VIN M 12 MODE 4 PULSE I/O Figure 1. YUV Filter with Sync on Y Input and Auto Clamp On PULSE I/O ML6424-2 6 VIN P 7 VIN M 4 PULSE I/O 6 VIN M 12 MODE ML6424-2 1µF 7 1µF 12 MODE 4 VIN P 4 PULSE I/O ML6424-2 1µF 6 +5V 12 MODE +5V 12 MODE 4 ML6424-1 1µF ML6424-2 1µF V 75Ω PULSE I/O 6 VIN P 7 VIN M 12 MODE 4 PULSE I/O Figure 2. YUV Filter with External Sync for U/V 5 ML6424/ML6425 ML6424-1 1µF Y 75Ω 6 VIN P 7 VIN M +5V 12 MODE 4 ML6424-2 1µF C 75Ω PULSE I/O 6 VIN P 7 VIN M 12 MODE 4 PULSE I/O Figure 3. Y/C Filter 6 ML6424/ML6425 ML6424-1 RESPONSE CURVES +10 +0.3 0 +0.2 –10 +0.1 0.0 AMPLITUDE (dB) AMPLITUDE (dB) –20 –30 –40 –50 –0.1 –0.2 –0.3 –60 –0.4 –70 –0.5 –80 –0.6 –90 0.1 1 10 50 –0.7 100k FREQUENCY (MHz) 3M 6M FREQUENCY (Hz) Figure 4. Amplitude vs Frequency Figure 5. Amplitude vs Frequency 0˚ PHASE (45˚/div) PHASE (10˚/div) 0˚— 500k 5.5M 500k 5.5M FREQUENCY (Hz) FREQUENCY (Hz) Figure 7. Deviation from Linear Phase Figure 6. Phase vs Linear Frequency 380 GROUP DELAY (ns) 360 340 320 300 280 100k 3M 6M FREQUENCY (Hz) Figure 8. Group Delay vs Frequency 7 ML6424/ML6425 ML6424-2 RESPONSE CURVES +0.4 +10 +0.3 0 +0.2 –10 +0.1 AMPLITUDE (dB) AMPLITUDE (dB) –20 –30 –40 –50 –0.1 –0.2 –0.3 –60 –0.4 –70 –0.5 –80 –90 0.1 0.0 1 10 30 –0.6 100k FREQUENCY (MHz) 0˚ PHASE (5˚/div) PHASE (45˚/div) 0˚ 200k 2.2M Figure 11. Phase vs Linear Frequency 690 650 610 570 530 1.5M FREQUENCY (Hz) Figure 13. Group Delay vs Frequency 2.2M Figure 12. Deviation from Linear Phase 730 100k 200k FREQUENCY (Hz) FREQUENCY (Hz) GROUP DELAY (ns) 3M Figure 10. Amplitude vs Frequency Figure 9. Amplitude vs Frequency 8 1.5M FREQUENCY (Hz) 3M ML6424/ML6425 ML6425-1 RESPONSE CURVES 20 +4dB 10 3.0 RELATIVE AMPLITUDE (dB) RELATIVE AMPLITUDE (dB) 0 –10 –20 –30 –40 –50 2.0 1.0 0 –60 –70 –80 100k 1M 0.1 10M 1 2 3 FREQUENCY (MHz) FREQUENCY (Hz) Figure 15. Amplitude vs Frequency 0˚ 0˚ PHASE (45˚/div) PHASE (10˚/div) Figure 14. Amplitude vs Frequency 500k 5.5M 500k 5.5M FREQUENCY (Hz) FREQUENCY (Hz) Figure 16. Phase vs Frequency Figure 17. Deviation from Linear Phase 410 390 GROUP DELAY (ns) 370 350 330 310 290 270 250 230 210 100k 3.5M 6M FREQUENCY (Hz) Figure 18. Group Delay vs Frequency 9 ML6424/ML6425 ML6425-2 RESPONSE CURVES 20 4 10 3 –10 AMPLITUDE (dB) RELATIVE AMPLITUDE (dB) 0 –20 –30 –40 2 1 –50 –60 0 –70 –80 100k 1M 100k 10M 6.0M FREQUENCY (Hz) FREQUENCY (Hz) Figure 19. Amplitude vs Frequency Figure 20. Amplitude vs Frequency PHASE (5˚/div) PHASE (45˚/div) 0˚ 200k 200k 2.2M 2.2M FREQUENCY (Hz) FREQUENCY (Hz) Figure 21. Phase vs Linear Frequency Figure 22. Deviation from Linear vs Phase 6 CUT OFF FREQUENCY (Hz) GROUP DELAY (20ns/div) 630 ML6424/25-1 5 4 3 ML6424/25-2 100k 3.0M FREQUENCY (Hz) Figure 23. Group Delay vs Frequency 10 2 8 9 10 11 REXT (k) Figure 24. Frequency vs REXT 12 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 FREQ SIN X/X TEMPERATURE RANGE PACKAGE ML6424-1 5.5 NO 0⋅C to 70⋅C 16-Pin SOIC (S16W) (Obsolete) ML6424-2 2.75 NO 0⋅C to 70⋅C 16-Pin SOIC (S16W) ML6425-1 5.5 YES 0⋅C to 70⋅C 16-Pin SOIC (S16W) (Obsolete) ML6425-2 2.75 YES 0⋅C to 70⋅C 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. 12 2092 Concourse Drive San Jose, CA 95131 Tel: 408/433-5200 Fax: 408/432-0295 DS6424_25-01