MIC1700 Micrel MIC1700 HDTV/SDTV 6th Order Video Filter for Component Video plus Composite Video General Description Features The MIC1700 is a complete reconstruction filter solution for high definition set-top boxes. The device has two independent component inputs (YPRPB or RGB) selectable via a 2-to-1 multiplexer, and a separate Svideo input (Y/C). Component channel filters have a selectable cutoff frequency (8MHz or 36MHz) to support both standard (SD) and high definition (HD) applications. S-video filters have fixed cutoff (8MHz) to support legacy composite applications. In addition, S-video channels are summed to provide a filtered CV output for an RF modulator or VCR. All inputs are DC-coupled with a 0V to 1V peak-to-peak range. All outputs are designed to drive 2V peak-to-peak into AC-coupled 150Ω loads. This supports 1V peak-to-peak into a 75Ω load with a 75Ω series source terminator. Filters have 6th order near Butterworth characteristics with cutoffs of 8MHz (SD and CV) and 36MHz (HD). These characteristics are chosen to provide good passband flatness with sufficient stop band attenuation and minimal group delay distortion. The device operates from a 5VDC supply. Data sheets and support documentation are available at Micrel’s web site, www.micrel.com. • • • • • • • • • • • S-video (Y/C) input, S-video and summed (CV) output 2 YPRPB or RGB inputs, YPRPB or RGB output YPRPB/RGB 2-1 input multiplexer DC coupled inputs – AC-coupled output drive 6db output gain for 75Ω source termination Component filters selectable for SD or HD cutoffs 6th order Butterworth characteristic Flat passband (HD 0.5dB @ 30MHz typ) Low group delay distortion (HD: 12ns @ 30MHz typ) Single 5V supply 28-pin wide body SOIC package (with exposed pad for improved thermal performance) Applications • • • • • • • HDTV HDTV set-top boxes Video games HDTV systems DVD players Digital satellite set-top boxes HDTV monitors Ordering Information Part Number Junction Temp. Range Package 0°C to +70°C SOIC-28 MIC1700BWME Typical Application MIC1700x-x HSEL 1 Y1A 2 Y1B 3 PR1 4 PR2 5 6 Composite Inputs PB1 7 PB2 8 YIN CIN 9 10 11 MUX 12 HSEL Y1A Y1B VCC VCC Y1OUT VCC 28 27 26 4.7µF 220µF 0.1µF 75Ω Y1OUT 75Ω PR1 PROUT 25 PBOUT PB1 GND PB2 YOUT YIN 75Ω COUT 24 220µF 75Ω 22 MUX PBOUT 75Ω 23 220µF 75Ω YOUT 75Ω 21 220µF 75Ω COUT 75Ω CIN GND PROUT 75Ω PR2 GND 220µF CVOUT GND VCC GND 20 220µF 18 75Ω CVOUT 75Ω 19 VCC 17 Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com October 2003 1 MIC1700 MIC1700 Micrel Pin Configuration HSEL 1 28 VCC Y1A 2 27 VCC Y1B 3 26 Y1OUT PR1 4 25 PROUT PR2 5 24 PBOUT GND 6 23 GND PB1 7 22 YOUT PB2 8 21 COUT YIN 9 20 CVOUT CIN 10 19 GND GND 11 18 VCC MUX 12 17 GND NC 13 16 NC NC 14 15 NC 28-Pin Wide Body SOIC (WM) Pin Description Pin Number Pin Name 1 HSEL Digital (Input): selects for the HD or SD filtering. A high selects HD filters. 2 Y1A Y (Input): component channel 1, selected when the MUX is high. 0V to 1V range. 3 Y1B Y (Input): component channel 2, selected when the MUX is low. 0V to 1V range. 4 PR1 PR (Input): component channel 1, selected when the MUX is high. 0V to 1V range. 5 PR2 PR (Input): component channel 2, selected when the MUX is low. 0V to 1V range. 6, 11, 17, 19, 23 GND Ground. 7 PB1 PB (Input): component channel 1, selected when the MUX is high. 0V to 1V range. 8 PB2 PB (Input): component channel 2, selected when the MUX is low. 0V to 1V range. 9 YIN Legacy (S-video): luminance input, 0V to 1V. 10 CIN Legacy (S-video): chroma input, 0V to 1V. 12 MUX Digital MUX control to select input 1 or 2 of the component channel. A high selects input 1. 13, 14, 15, 16 NC 18, 27, 28 VCC 20 CVOUT 21 COUT Legacy chroma output, typically 1V to 3V. 22 YOUT Legacy luminance video output, typically 1V to 3V. 24 PBOUT PB color component output, either SD or HD, typically 1V to 3V. 25 PROUT PR color component output, either SD or HD, typically 1V to 3V. 26 Y1OUT Luminance component output, either SD or HD, typically 1V to 3V. MIC1700 Pin Function No connect. Do not connect these pins. Positive side of the 5V power supply. Legacy composite video output, typically 1V to 3V. 2 October 2003 MIC1700 Micrel Truth Table MUX Select Pin H L H HDTV Mode Y1A, PB1, PR1 Inputs HDTV Mode Y1B, PB2, PR2 Inputs L SD Mode Y1A, PB1, PR1 Inputs SD Mode Y1B, PB2, PR2 Inputs HSEL October 2003 3 MIC1700 MIC1700 Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Maximum Input Voltage ................................................ VCC Supply Voltage ................................................................ 6V Lead Temperature (soldering, 5 sec) ........................ 260°C ESD Rating, ............................................................. Note 3 Analog Input Voltage Range .............................. 0V to 1.1V Digital Input Voltage Range ................................... 0 to VCC Supply Voltage (VCC) ...............................................5V±5% Ambient Temperature Range ....................... –0°C to +70°C Package Thermal Resistance SOIC (θJA), Note 4, 6 .......................................... 35°C/W Electrical Characteristics (Note 5) VCC = 4.75V to 5.25V, TA = 25°C. Values in bold apply over entire operating temperature range. TA from 0°C to +70°C. Values apply to all channels unless noted. Symbol Parameter Conditions PD Power Dissipation VO Typ Max Units No load 725 900 mW Linear Output Range RL = 150Ω, AC-Coupled 2.0 2.2 V ZIN Input Impedance, Note 7 VIN = 0V to 1V 1 MΩ IIN Input Bias Current, Note 7 VIN = 0V to 1V 40 µA Crosstalk, Note 7 channel-to-channel, f = 3MHz, NTSC Mode –70 dB Crosstalk, Note 7 channel-to-channel, f = 20MHz, HDTV Mode –64 dB Crosstalk, Note 7 between MUX inputs, f = 3MHz –60 dB Power Supply Rejection Ratio at 400kHz 40 dB 36 MHz 30 MHz dB PSSR Min Filter Specifications, HD Operating Mode f–3dB –3dB Bandwidth VAC = 0.5Vp-p, VDC = 0.5V f–1dB –1dB Bandwidth VAC = 0.5Vpk-pk, VDC = 0.5V A74MHz 74MHz Attenuation VAC = 0.5Vpk-pk, VDC = 0.5V 25 30 Av Low Frequency Gain VAC = 0.5Vpk-pk, VDC = 0.5V at 400kHz 5.5 6 Av Gain Matching VAC = 0.5Vpk-pk, VDC = 0.5V channel-to-channel PK Peaking, Note 7 TD Baseband Delay TGD 33 30 6.3 dB 1 % 1 dB f = 100kHz 65 ns Group Delay distortion f = 3.6MHz f = 6.0MHz 5 20 ns ns SNR Signal to Noise, Note 7 Note 2 77 dB DG Differential Gain, Note 7 40IRE modulated ramp 2 % DP Differential Phase, Note 7 @ both 3.58MHz and 4.43MHz 2 ° 7.9 MHz Filter Specifications, NTSC/PAL Operating Mode f–1dB –1dB Bandwidth VAC = 0.5Vpk-pk, VDC = 0.5V f–3dB –3dB Bandwidth VAC = 0.5Vpk-pk, VDC = 0.5V 7.6 8.7 MHz A27MHz 27MHz Attenuation VAC = 0.5Vpk-pk, VDC = 0.5V 36 44 dB Av Low Frequency Gain VAC = 0.5Vpk-pk, VDC = 0.5V at 400kHz 5.5 6 Av Gain Matching channel-to-channel 1 % GD Group Delay, Note 7 f = 3.6MHz 70 ns SNR Signal to Noise, Note 7 Note 8 68 dB VIH Input High HSTL and MUX pin VIL Input Low HSTL and MUX pin 6.3 dB Digital I/O MIC1700 4 2.0 V 0.5 V October 2003 MIC1700 Micrel Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Devices are ESD sensitive. Handling precautions recommended. Note 4. With SOIC attached by leads only. Note 5. Specification for packaged product only. Note 6. When thermally enhanced SOIC heatsink pad is soldered to a copper pad on a single layer PCB. Note 7. Guaranteed by design and characterization. Note 8. Low pass filter enabled. VIN = 1Vpk-pk. Wideband noise floor over 20MHz. October 2003 5 MIC1700 MIC1700 Micrel Typical Characteristics 10 0 3 2 1 0 -1 -2 1M 100M HDTV Gain 20 7 6 10 0 5 4 -10 -20 3 2 -1 -2 1M 10M 1M 100M 2 4 100M -70 -80 1M 6 8 10 12 14 16 FREQUENCY (MHz) HDTV Group Delay HDTV Gain 35 30 -30 -40 -50 -60 10M FREQUENCY (Hz) Input Signal = 50mVp-p VDC = 0.5V 110 100 90 80 70 60 50 40 30 20 10 0 0 FREQUENCY (Hz) 1 0 MIC1700 -30 -40 -70 -80 100k GAIN (dB) GAIN (dB) 8 -10 -20 -50 -60 10M FREQUENCY (Hz) GROUP DELAY (ns) 5 4 Input Signal = 50mVp-p VDC = 0.5V NTSC Group Delay NTSC Gain 20 GROUP DELAY (ns) GAIN (dB) 7 6 NTSC Gain GAIN (dB) 8 Input Signal = 50mVp-p VDC = 0.5V 10M FREQUENCY (Hz) 6 25 20 15 10 5 100M 0 0 10 20 30 40 50 60 FREQUENCY (MHz) October 2003 MIC1700 Micrel Functional Diagram HSEL (HDTV or NTSC/PAL Select) MUX Select Y1A Y1B 2:1 MUX Selectable Filter Y1OUT PR1 PR2 2:1 MUX Selectable Filter PROUT PB1 PB2 2:1 MUX Selectable Filter PBOUT Component Video YOUT YIN 8MHz Filter CVOUT CIN Composite Video 8MHz Filter COUT MIC1700 Block Diagram between 8MHz SD (Standard Definition) and 36MHz HD (High Definition). The 6th order Butterworth characteristic provides a maximally flat passband with 39dB of attenuation an octave above cutoff, and low group delay distortion minimizes overshoots in the time domain. Composite Filters The composite filters have the same characteristics as the SD mode of the component filters. These filters are additionally specified for DG (differential gain, variation of subcarrier amplitude with luma level) and DP (differential phase, variation of subcarrier phase with luma level). These distortions (which are intermodulation distortions) cannot occur with true S-video inputs applied, since luma and chroma are in separate channels. However, the composite filters can also be used with full legacy composite signals. In these cases, the DG and DP specifications are applicable. Output Drivers The output drivers are configured to provide low distortion 2V peak-to-peak swing into a 150Ω load from a single +5V supply. To achieve this, the operating range is approximately from 1V to 3V for normal inputs. AC-coupling at the outputs helps keep power dissipation within specification while preventing excessive DC components from coupling to downstream equipment. Functional Description The MIC1700 is a multi-channel active filtering device with channels for both component and composite video signals. Component channel filters have selectable SD or HD bandwidths while composite filters have fixed bandwidth. One of two component inputs may be selected via a 2-to-1 mux. Output drivers are sufficient to drive 1V signals into 75Ω loads via a 75Ω source terminator. Input Inputs are all high impedance with low input bias current. Signal excursions at the inputs are limited to a specified range of 0V to 1V to meet distortion and other performance specifications. Two groups of three pins each comprise the two selectable component inputs, intended for YPRPB or RGB applications. One group of two pins comprises the composite S-video input, intended for legacy applications. Component Multiplexer Either of two component inputs may be selected using the component input multiplexer. The output of this high isolation multiplexer feeds the internal component filters. Input characteristics are not altered by the action of the multiplexer. Component Filters The component filters are 6th order with near Butterworth response characteristics. Cutoff frequencies are selectable October 2003 7 MIC1700 MIC1700 Micrel Applications Information +5V Achieving Additional Stop Band Attenuation For customers requiring greater stop band attenuation, a simple passive filter can be added to the input of MIC1700. The following circuit increases stop band attenuation above 60MHz by at least 15dB. Attenuation at the critical clocking frequency of 74MHz is increased by at least 20dB even allowing for typical value variations (we recommend 5% inductor, 2% capacitors). R1 1.5k Q4 Q2N3904 RGB Video Source +5V Comparison of Response 0 C2* 10µF MIC1700 Q5 Q2N3904 +5V C3* 10µF -10 R3 20k R4 20k MIC1700 C1* 10µF 10 GROUP DELAY (ns) +5V Q6 Q2N3904 -20 -30 R5 20k MIC1700 with Passive Filter -40 -50 Stopband Improvement -60 1 10 100 C4 10µF 300 Q7 Q2N3904 FREQUENCY (MHz) *Polarity dependant on DC operating point of source Figure 1. Comparison of Response Figure 4. Triple Clamp for RGB Applications Clamps for AC-Coupled Inputs For RGB or Composite inputs that do not meet the DC input requirements MIC1700 can be driven via sync tip clamps (RGB sources work best with sync on all channels). These clamps work with signals that are unipolar, in which the sync tip is the most negative excursion of the signal. Current is bled from the input capacitor during active video causing a slow droop in average level. This rate of droop is a critical video parameter and should be well under 1% for all operating conditions. The droop is controlled by the load resistance (plus additional load currents) and the coupling cap. Charge removed from the coupling cap during active video is replaced during sync tip by the emitter current of the clamping transistor. The VBE drop during sync will be a function of the replacement current which is a function of sync tip duty cycle. Sync tip duty cycle for SD is 4.7µs/63.5µs = 0.074 or 7.4%. For HD trilevel sync the duty cycle is about half of this or 0.037. Assuming a droop current of about 100µA, this gives a maximum replacement current (for HD signals) of 2.7mA. To keep this sync tip at or above GND, the biasing transistor should be operated at the same current, giving a biasing resistor of 1.5kΩ. This will bias HD sources with the sync tip at GND, with SD sources slightly above GND. The luma channel of S-video sources can be clamped the same as component RGB channels, but the chroma channel should simply be AC-coupled with a bias of 0.5V. Realization of these schemes is shown in Figure 4 and 5. 22pF 75Ω Encoder Output 220nH MIC1700 Input 62pF Figure 2. Passive Filter Circuit for 75Ω source 47pF 37.5Ω Encoder Output 100nH MIC1700 Input 130pF Figure 3. Passive Filter Circuit for 37.5Ω source MIC1700 8 October 2003 MIC1700 Micrel +5V +5V R1 1.5k Q4 Q2N3904 R2 20k C4 10µF Q7 Q2N3904 MIC1700 RGB Video Source C1* 10µF +5V C2* 10µF R4 1.8k *Polarity dependant on DC operating point of source Figure 5. Clamp and AC Biasing for S-Video Applications October 2003 9 MIC1700 MIC1700 Micrel Package Information 28-Pin Wide Body SOIC (WM) MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated. MIC1700 10 October 2003