ML6428 S-Video Filter and 75W Line Drivers with Summed Composite Output GENERAL DESCRIPTION FEATURES The ML6428 is a dual Y/C 4th-order Butterworth lowpass video filter optimized for minimum overshoot and flat group delay. The device also contains a summing circuit to generate filtered composite video. The Y and C input signals from DACs are AC coupled into the ML6428. Both channels have DC restore circuitry to clamp the DC input levels during video sync. The Y channel uses a sync tip clamp. The CV and the C channels share a feedback clamp. All outputs must be AC coupled into their loads for the -1 and -3 versions. The -2 and -4 versions are DC coupled. All inputs (-1, -2, -3 and -4 versions) are AC coupled. The Y or C outputs can drive 2VP-P into a 150W load, while the CV output can drive 2VP-P into 75W. Thus the CV output is capable of driving two independent 150W loads to 2VP-P. On the CV output, one of the 75W loads can be shorted to ground with no loss of drive to the remaining load. The Y, C and CV channels have a gain of 2 (6dB) with 1VP-P input levels. ■ 6.7MHz Y and C filters, with CV out for NTSC or PAL ■ 75W cable line driver for Y, C, CV, and TV modulator ■ 43dB stopband attenuation at 27MHz ■ 1dB flatness up to 4.8MHz ■ No external frequency select components or clocks ■ 12ns group delay flatness up to 10MHz ■ 5% overshoot on any input edge ■ AC coupled input and output (ML6428CS-1 and -3) ■ AC coupled input and DC coupled output (ML6428CS-2 and -4) ■ 0.4% differential gain on all channels, 0.4º differential phase on all channels ■ 0.7% total harmonic distortion on all channels ■ 5V ±10% operation ■ DC restore with low tilt BLOCK DIAGRAM YIN VCC VCCO 2 7 4th-ORDER FILTER 1 YOUT 6 CVOUT 5 COUT + SYNC TIP CLAMP Σ TRANSCONDUCTANCE ERROR AMP CIN 4 8 BUFFER BUFFER + 4th-ORDER FILTER BUFFER 3 GND DATASHEET June, 2000 1 ML6428 TABLE OF CONTENTS General Description ................................................................................................................................................... 1 Features ...................................................................................................................................................................... 1 Block Diagram ........................................................................................................................................................... 1 Pin Configuration ....................................................................................................................................................... 3 Pin Descriptions ......................................................................................................................................................... 3 Absolute Maximum Ratings ........................................................................................................................................ 4 Operating Conditions ................................................................................................................................................. 4 Electrical Characteristics ..................................................................................................... ....................................... 4 Functional Description ............................................................................................................................................... 6 Performance Data ....................................................................................................................................................... 7 Typical Applications ................................................................................................................................................... 8 Physical Dimensions .................................................................................................................................................. 11 Ordering Information .................................................................................................................................................. 11 WARRANTY © Micro Linear 2000. is a registered trademark of Micro Linear Corporation. All other trademarks are the property of their respective owners. Products described herein may be covered by one or more of the following U.S. 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; 5,592,128; 5,594,376; 5,652,479; 5,661,427; 5,663,874; 5,672,959; 5,689,167; 5,714,897; 5,717,798; 5,742,151; 5,747,977; 5,754,012; 5,757,174; 5,767,653; 5,777,514; 5,793,168; 5,798,635; 5,804,950; 5,808,455; 5,811,999; 5,818,207; 5,818,669; 5,825,165; 5,825,223; 5,838,723; 5.844,378; 5,844,941. Japan: 2,598,946; 2,619,299; 2,704,176; 2,821,714. Other patents are pending. Micro Linear makes no representations or warranties with respect to the accuracy, utility, or completeness of the contents of this publication and reserves the right to make changes to specifications and product descriptions at any time without notice. No license, express or implied, by estoppel or otherwise, to any patents or other intellectual property rights is granted by this document. The circuits contained in this document are offered as possible applications only. Particular uses or applications may invalidate some of the specifications and/or product descriptions contained herein. The customer is urged to perform its own engineering review before deciding on a particular application. Micro Linear assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of Micro Linear products including liability or warranties relating to merchantability, fitness for a particular purpose, or infringement of any intellectual property right. Micro Linear products are not designed for use in medical, life saving, or life sustaining applications. 2 DATASHEET June, 2000 ML6428 PIN CONFIGURATION ML6428 8-Pin SOIC (S08) YIN 1 8 YOUT VCC 2 7 VCCO GND 3 6 CVOUT CIN 4 5 COUT TOP VIEW PIN DESCRIPTION PIN NAME FUNCTION PIN NAME FUNCTION 1 YIN Luminance input 5 COUT Chrominance output 2 VCC 5V supply for filters and references 6 CVOUT Composite video output 3 GND Ground 7 VCCO 5V supply for output stages 4 CIN Chrominance input 8 YOUT Luminance output DATASHEET June, 2000 3 ML6428 ELECTRICAL CHARACTERISTICS 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. Temperature Range ....................................... 0°C to 70°C VCC Range ..................................................4.5V to 5.5V DC Supply Voltage ........................................ -0.3V to 7V Analog & Digital I/O ............ GND – 0.3V to VCC + 0.3V Output Current (Continuous) CV Channel ........................................................ 60mA C and Y Channels ................................................ 30mA Junction Temperature .............................................. 150°C Storage Temperature Range ..................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) ..................... 260°C Thermal Resistance (qJA) ..................................... 67°C/W ELECTRICAL TABLE Unless otherwise specified, VCC = 5V ±10%, All inputs AC coupled with 100nF, TA = Operating Temperature Range (Note 1) SYMBOL PARAMETER MIN TYP MAX UNITS 52 80 mA 5.34 6.0 6.65 dB ICC Supply Current No Load (VCC = 5.0V) AV Low Frequency Gain (All Channels) VIN = 100mVP-P at 300KHz C DC Output Level (During Sync) Sync Present on Y 1.7 1.9 2.3 V Y Sync Output Level ML6428-1 ML6428-3 Sync Present on Y 0.7 0.9 1.3 V ML6428-2 ML6428-4 Sync Present on Y 0.35 0.54 0.95 V ML6428-1 ML6428-3 Sync Present on Y 0.7 0.92 1.3 V ML6428-2 ML6428-4 Sync Present on Y 0.35 0.48 0.95 V Y+C Sync Output Level tCLAMP Clamp Response Time (Y Channel) Settled to Within 10mV 4.0 2 ms 4.8 MHz f1dB -1dB Bandwidth (Flatness) (All Channels) fC -3dB Bandwidth (Flatness) (All Channels) 6.7 MHz 0.8 x fC Attenuation (Y, C) 1.5 dB –38 –42 dB ML6428-1, -2 1.0 1.4 VP-P ML6428-3, -4 1.2 1.4 VP-P 0.8fC fSB Stopband Rejection (All Channels) Vi Input Signal Dynamic Range (All Channels) AC Coupled NOISE 4 CONDITIONS fIN = 27MHz to 100MHz worst case Output Noise (All Channels) 25Hz to 50MHz 2.3 mVRMS OS Peak Overshoot (All Channels) 2VP-P Output Pulse (loaded) 4.3 % ISC Output Short Circuit Current (All Channels) VOUT C, Y, or CV (Note 2) 100 mA CL Output Shunt Capacitance (All Channels) All Outputs dG Differential Gain (All Channels) All Outputs 0.4 % dF Differential Phase (All Channels) All Outputs 0.4 º THD Output Distortion (All Channels) VOUT = 1.8VP-P, Y/C Out at 3.58MHz/4.43MHz 0.7 % DATASHEET 35 June, 2000 pF ML6428 ELECTRICAL TABLE (CONTINUED) SYMBOL XTALK PARAMETER CONDITIONS TYP MAX UNITS From C Input of 0.5VP-P at 3.58MHz/4.43MHz, to Y Output –55 dB From Y Input of 0.4VP-P at 3.58MHz, to C Output –58 dB PSRR (All Channels) 0.5VP-P (100kHz) at VCC –49 dB tpd Group Delay (All Channels) 100kHz 60 ns Dtpd Group Delay Deviation from Flatness to 3.58MHz (NTSC) 4 ns (All Channels) to 4.43MHz (PAL) without peaking (see Figures 7 to 11) 7 ns 12 ns PSRR Crosstalk MIN to 10MHz tSKEW Skew Between Y & C Outputs 1 ns Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions. Note 2: Sustained short circuit protection limited to 10 seconds. DATASHEET June, 2000 5 ML6428 FUNCTIONAL DESCRIPTION The ML6428 is a dual monolithic continuous time video filter designed for reconstructing the luminance and chrominance signals from an S-Video D/A source. Composite video output is generated by summing the Y and C outputs. The ML6428 is intended for use in AC coupled input and output applications. The ML6428CS-2, -4 is intended for AC coupled input and DC coupled output applications (see Figures 5 and 6). The filters have a 4th-order Butterworth characteristic with an optimization toward low overshoot and flat group delay. All outputs are capable of driving 2VP-P into AC coupled 150W video loads, with up to 35pF of load capacitance at the output pin. The CV output can drive two video loads plus a high-impedance modulator. Thus the CV output is intended to simultaneously drive a VCR, a TV, and a high-impedance modulator. Y and C are capable of driving a 75W load at 1VP-P. The ML6428 is capable of driving two composite loads and a TV modulator simultaneously. All channels are clamped during sync to establish the appropriate output voltage swing range. Thus the input coupling capacitors do not behave according to the conventional RC time constant. Clamping for all channels settles within 2ms of a change in video input sources. In most applications, the ML6428's input coupling capacitors are 0.1µF. The Y input sinks 1.6µA during active video, which nominally tilts a horizontal line by 2mV (max) at the Y output (Figure 4). During sync, the clamp typically sources 20µA to restore the DC level. The net result is that the average input current is zero. Any change in the input coupling capacitor's value will inversely alter the amount of tilt per line. Such a change will also linearly affect the clamp response times. The C channel has no pulldown current sources and is essentially tilt-free. Its input is clamped by a feedback amp which responds to the CV output. Since CV = Y+C, the CV output will droop by the same amount as Y during active video, and will rise by the same amount as Y during sync. The ML6428 is robust and stable under all stated load and input conditions. Capacitavely bypassing both VCC pins directly to ground ensures this performance. (See Figures 5 and 6) 6 DATASHEET LUMINANCE (Y) I/O The luma input is driven by either a low impedance source of 1VP-P or the output of a 75W terminated line. The input is required to be AC coupled via a 0.1uF coupling capacitor which allows for a nominal settling time of 2ms. The luma output is capable of driving an AC coupled 150W load at 2VP-P or 1VP-P into a 75W load. Up to 35pF of load capacitance (at the output pin) can be driven without stability or slew issues. A 220µF AC coupling capacitor is recommended at the output (ML6428-1, -3 only). CHROMINANCE (C) I/O The chroma input is driven by a low impedance source of 0.7VP-P or the output of a 75W terminated line. The input is required to be AC coupled via a 0.1uF coupling capacitor which allows for a nominal clamping time of 1ms. The chroma output is capable of driving an AC coupled 150W load at 2VP-P or 1VP-P into a 75W load. Up to 35pF of load capacitance can be driven without stability or slew issues. A 220µF AC coupling capacitor is recommended at the output (ML6428-1, -3 only). COMPOSITE VIDEO (CV) OUTPUT The composite video output is capable of driving 2 CV loads to 2VP-P and a high input impedance CV modulator. It is intended to drive three devices: TV, VCR, and a modulator. The TV or VCR input can be shorted to ground and the other outputs will still meet specifications. Up to 35pF of load capacitance (at the output pin) can be driven without stability or slew issues. USING THE ML6428 FOR PAL APPLICATIONS The ML6428 can be optimized for PAL video by adding frequency peaking to the composite and S-video outputs. Figures 7 and 8 illustrate the use of a additional external capacitor, 330pF, added in parallel to the output source termination resistor. This raises the frequency response from 1.6 dB down at 4.8Mhz to 0.35dB down at 4.8MHz allowing for accurate reproduction of the upper sideband of the PAL subcarrier. Figure 9 shows the frequency response of PAL video with various values of peaking capacitors (0pF, 220pF, 270pF, 330pF) between 0 and 10MHz. For NTSC applications without the peaking capacitor the rejection at 27MHz is 42dB (typical) while for PAL applications with the peaking capacitor the rejection at 27MHz is 38dB (typical). This is shown in Figure 10. The differential group delay is shown in Figure 11 with and without a peaking capacitor (0pF, 220pF, 270pF, and 330pF) varies slightly with capacitance, going from 8ns to 13ns. June, 2000 ML6428 1 20 0 0 AMPLITUDE (dB) AMPLITUDE (dB) PERFORMANCE DATA –1 –2 –3 –4 –20 –40 –60 0 0.1 1 –80 0.01 10 FREQUENCY (MHz) 0.1 1 10 100 FREQUENCY (MHz) Figure 1. Passband Flatness All outputs. (Normalized) Passband is ripple-free. Figure 2. Passband/Stopband Rejection Ratios All outputs. (Normalized) 90 SCALE: 200mV/DIV DELAY (ns) 70 50 30 REGION OF TILT 10 1 2 3 4 5 6 7 8 9 10 11 FREQUENCY (MHz) SCALE: 200ms/DIV Figure 3. Group Delay, all Outputs Low frequency group delay is 62ns. At 3.58MHz group delay increases by only 4ns. At 4.43MHz group delay increases by only 7ns. The maximum deviation from flat group delay of 12ns occurs at 6MHz. DATASHEET Figure 4. DC Restore Performance of Luma Output Luma ramp test pattern is shown to have minimal tilt during vertical sync. In most applications, the ML6428's input coupling capacitors are 0.1µF. The Y input sinks 1.6µA during active video, which tilts a horizontal line by 2mV at the Y output June, 2000 7 ML6428 TYPICAL APPLICATIONS ML6428-1, -3 0.1µF 220µF 1 YIN 8 4th-ORDER FILTER VIDEO CABLES 75Ω YOUT 75Ω + 220µF Σ 6 75Ω CVOUT 75Ω + 0.1µF 4 CIN 220µF 5 4th-ORDER FILTER 75Ω CVOUT 75Ω C* 2 7 R* 3 ON-CHANNEL MODULATOR, VCR, AND TV 5V 220µF 75Ω COUT 0.1µF 75Ω 1µF * C AND R DEPEND ON THE INPUT IMPEDANCE OF LOAD Figure 5. AC Coupled S-Video and Composite Video Line Driver for NTSC ML6428-2, -4 0.1µF 1 YIN VIDEO CABLES 75Ω 8 4th-ORDER FILTER YOUT 75Ω + Σ 75Ω 6 CVOUT 75Ω + 0.1µF CIN 4 75Ω 5 4th-ORDER FILTER CVOUT 75Ω C* 2 7 R* 3 ON-CHANNEL MODULATOR, VCR, AND TV 5V 75Ω COUT 75Ω 0.1µF 1µF * C AND R DEPEND ON THE INPUT IMPEDANCE OF LOAD Figure 6. DC Coupled S-Video and Composite Video Line Driver for NTSC 8 DATASHEET June, 2000 ML6428 TYPICAL APPLICATIONS ML6428-1, -3 0.1µF 220µF 1 YIN 8 4th-ORDER FILTER VIDEO CABLES 75Ω YOUT 75Ω + 330pF 220µF Σ 6 75Ω CVOUT 75Ω 4 CIN 330pF + 0.1µF 220µF 5 4th-ORDER FILTER 75Ω CVOUT 75Ω C1* 2 7 3 330pF ON-CHANNEL MODULATOR, VCR, AND TV R* 5V 220µF 0.1µF C2* 75Ω COUT 75Ω 1µF 330pF * C1, C2, AND R DEPEND ON THE INPUT IMPEDANCE OF LOAD Figure 7. AC Coupled S-Video and Composite Video Line Driver for PAL ML6428-2, -4 0.1µF 1 YIN VIDEO CABLES 75Ω 8 4th-ORDER FILTER YOUT 75Ω + 330pF Σ 75Ω 6 CVOUT 75Ω 0.1µF CIN 330pF + 4 75Ω 5 4th-ORDER FILTER CVOUT 75Ω C1* 2 7 3 330pF ON-CHANNEL MODULATOR, VCR, AND TV R* C2 5V 75Ω COUT 75Ω 0.1µF 1µF 330pF * C1, C2, AND R DEPEND ON THE INPUT IMPEDANCE OF LOAD Figure 8. DC Coupled S-Video and Composite Video Line Driver for PAL DATASHEET June, 2000 9 ML6428 TYPICAL APPLICATIONS –0.5 0.35dB WITH PEAKING AMPLITUDE (dB) 0 0.5 1.7dB WITHOUT PEAKING 1 1.5 330pF 270pF 2 220pF 0pF 2.5 0 2 1 4 3 6 5 8 7 FREQUENCY (MHz) Figure 9. NTSC/PAL Video Frequency Response With and Without Peaking Capacitor 0 AMPLITUDE (dB) 10 NTSC/PAL –38dB WITH PEAKING 20 30 NTSC/PAL –42dB WITHOUT PEAKING 330pF 40 270pF 220pF 0pF 50 0 3 6 9 12 15 18 21 24 27 30 FREQUENCY (MHz) Figure 10. Stopband Rejection at 27MHz With and Without Peaking Capacitor 10 8ns GROUP DELAY WITHOUT PEAKING DELAY (ns) 0 13ns GROUP DELAY WITH 330pF PEAKING –10 330pF 270pF 220pF 0pF –20 0 1 2 3 4 5 6 7 8 9 10 FREQUENCY (MHz) Figure 11. Group Delay at 5.5MHz (PAL) With and Without Peaking Capacitor 10 DATASHEET June, 2000 ML6428 PHYSICAL DIMENSIONS inches (millimeters) Package: S08 8-Pin SOIC 0.189 - 0.199 (4.80 - 5.06) 8 0.148 - 0.158 0.228 - 0.244 (3.76 - 4.01) (5.79 - 6.20) PIN 1 ID 1 0.017 - 0.027 (0.43 - 0.69) (4 PLACES) 0.050 BSC (1.27 BSC) 0.059 - 0.069 (1.49 - 1.75) 0º - 8º 0.055 - 0.061 (1.40 - 1.55) 0.012 - 0.020 (0.30 - 0.51) 0.015 - 0.035 (0.38 - 0.89) 0.004 - 0.010 (0.10 - 0.26) 0.006 - 0.010 (0.15 - 0.26) SEATING PLANE ORDERING INFORMATION PART NUMBER TEMPERATURE RANGE PACKAGE ML6428CS-1 0°C to 70°C 8 Pin SOIC (S08) ML6428CS-2 0°C to 70°C 8 Pin SOIC (S08) ML6428CS-3 0°C to 70°C 8 Pin SOIC (S08) ML6428CS-4 0°C to 70°C 8 Pin SOIC (S08) Micro Linear Corporation 2092 Concourse Drive San Jose, CA 95131 Tel: (408) 433-5200 Fax: (408) 432-0295 www.microlinear.com DS6428-02 DATASHEET June, 2000 11