19-2951; Rev 0; 8/03 4-Channel Video Filter for RGB and CVBS Video The MAX7446 processes CVBS and RGB video signals. The video output buffers have a fixed gain of +6dB. The channel for CVBS video has high-frequency boost circuitry that provides picture sharpness with +1.2dB of gain boost without degradation in the stopband. The output video drivers can be disabled with an external pin. The MAX7446 is available in a 14-pin TSSOP package with an exposed pad, and is specified over the -40°C to +85°C extended temperature range. Applications Set-Top Boxes/HDRs Game Consoles Desktop Video Editors DVD Players Features ♦ 4-Channel Filter and Buffer for RGB and CVBS Signals ♦ Filter Response Ideal for NTSC, PAL, and Interlaced SDTV Video Signals ♦ 43dB (typ) Stopband Attenuation at 27MHz ♦ ±0.75dB (max) Passband Ripple Out to 5MHz ♦ Blanking Level Voltage on Cable <1V ♦ Each Channel Drives Two 150Ω Video Loads ♦ +5V Single-Supply Voltage ♦ Small 14-Pin TSSOP Package Ordering Information PART MAX7446EUD TEMP RANGE PIN-PACKAGE -40°C to +85°C 14 TSSOP-EP* *EP = Exposed pad. Pin Configuration appears at end of data sheet. Digital VCRs Functional Diagram VCC ENCODER 75Ω 0.1µF CVBS D/A 75Ω * INA LOWPASS FILTER OUTA SYNC DETECTOR 75Ω * 75Ω 0.1µF R D/A LOWPASS FILTER OUTB LOWPASS FILTER OUTC LOWPASS FILTER OUTD 75Ω 75Ω INC D/A D/A 75Ω 75Ω 0.1µF B 75Ω * INB 0.1µF G (WITHOUT SYNC) 75Ω IND 75Ω * * * * * 75Ω 75Ω 75Ω 75Ω 75Ω *OPTIONAL CAPACITORS MAX7446 GND DISABLE ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX7446 General Description The MAX7446 4-channel, buffered video reconstruction filter is ideal for anti-aliasing and DAC-smoothing video applications or wherever analog video is reconstructed from a digital data stream (such as cable/satellite/terrestrial set-top boxes, DVD players, hard disk recorders (HDRs), and personal video recorders (PVRs)). This device operates from a single +5V supply and has a flat passband out to 5MHz with a stopband attenuation of 43dB at 27MHz. This makes it ideal for use with NTSC, PAL, and standard-definition digital TV (SDTV) video systems. Each output is capable of driving two standard 150Ω video loads. MAX7446 4-Channel Video Filter for RGB and CVBS Video ABSOLUTE MAXIMUM RATINGS VCC to GND ...........................................................................+6V All Other Pins to GND.................................-0.3V to (VCC + 0.3V) Maximum Current into Any Pin Except VCC and GND .....±50mA Continuous Power Dissipation (TA = +70°C) TSSOP-EP (derate 20.8mW/°C above +70°C) ...........1667mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Junction Temperature ......................................................+150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω to GND for DC-coupled load, RL = 75Ω to VCC / 2 for AC-coupled load, CIN_ = 0.1µF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, TA = +25°C.) PARAMETER SYMBOL CONDITIONS f = 100kHz to 5MHz, relative to 100kHz Passband Response Channel A Channels B, C, D MIN TYP MAX 0.9 1.2 1.5 -0.75 +0.15 +0.75 39 43 UNITS dB Stopband Attenuation ASB f ≥ 27MHz Differential Gain dG 5-step modulated staircase 0.15 0.50 % Differential Phase dθ 5-step modulated staircase 0.15 0.50 Degrees Signal-to-Noise Ratio SNR Peak signal (2VP-P) to RMS noise, f = 100Hz to 50MHz Group Delay Deviation ∆tg Deviation from 100kHz to 4.1MHz dB 80 dB Channel A 17 30 Channels B, C, D 11 20 ns Line-Time Distortion HDIST 18µs, 100 IRE bar 0.3 Field-Time Distortion VDIST 130 lines, 18µs, 100 IRE bar 0.5 % Clamp Settling Time tCLAMP To ±1% 100 Lines Output DC Clamp Level Channel A 0.6 0.9 1.1 Channels B, C, D 1.1 1.5 1.8 f = 100kHz -3 Low-Frequency Gain Accuracy AV Low-Frequency Gain Matching AV(MATCH) Low-frequency channel-to-channel matching, f = 100kHz Group Delay Matching tg(MATCH) Low-frequency channel-to-channel matching, f = 100kHz Channel-to-Channel Crosstalk XTALK Output Short-Circuit Current ISC Input Leakage Current IIN Input Dynamic Swing % V +3 % 4 % 2 ns f = 100kHz to 3.58MHz 60 dB OUT_ shorted to GND or VCC 70 mA 10 Channel A 1.2 Channels B, C, D 0.9 µA VP-P SUPPLY Supply Voltage Range VCC Supply Current ICC Power-Supply Rejection Ratio 2 PSRR 4.75 No load 100 VIN = 100mVP-P, f = 0 to 3.5MHz 40 _______________________________________________________________________________________ 5.25 V 140 mA dB 4-Channel Video Filter for RGB and CVBS Video (VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω to GND for DC-coupled load, RL = 75Ω to VCC / 2 for AC-coupled load, CIN_ = 0.1µF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DISABLE Output Impedance During Disable ZDISABLE Disable Logic-Input High Voltage VIH Disable Logic-Input Low Voltage VIL Disable Logic-Input Current At 5MHz 2 kΩ 2.0 IDISABLE V VIL = 0V (sink), VIH = VCC (source) 0.8 V ±10 µA Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) PASSBAND AMPLITUDE vs. FREQUENCY 0 1.5 PHASE RESPONSE vs. FREQUENCY 200 MAX7446 toc02 MAX7446 toc01 2.0 HIGH-FREQUENCY BOOST 150 -40 100 PHASE (DEGREES) AMPLITUDE (dB) AMPLITUDE (dB) 1.0 -20 0.5 0 -0.5 FLAT PASSBAND RESPONSE -1.0 -60 -50 -150 -2.0 10 -200 0.1 100 10 1 FREQUENCY (MHz) FREQUENCY (MHz) GROUP DELAY vs. FREQUENCY 2T RESPONSE (1 IRE = 7.14mV) 0.1 MAX7446 toc04 90 80 10 1 FREQUENCY (MHz) MODULATED 12.5T RESPONSE (1 IRE = 7.14mV) MAX7446 toc05 100 GROUP DELAY (ns) 0 NORMALIZED TO 0dB -80 1 50 -100 -1.5 NORMALIZED TO 0dB MAX7446 toc03 AMPLITUDE vs. FREQUENCY MAX7446 toc06 IN_ IN_ 250mV/div 250mV/div 70 OUT_ OUT_ 60 250mV/div 250mV/div 50 0.1 1 10 200ns/div 400ns/div FREQUENCY (MHz) _______________________________________________________________________________________ 3 MAX7446 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VCC = +5V, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE 110 100 90 80 -40 -15 10 35 60 85 TEMPERATURE (°C) MAX7446 toc09 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 MAX7446 toc08 DIFFERENTIAL PHASE (DEGREES) DIFFERENTIAL GAIN (%) INPUTS BIASED TO +2V NO LOAD MULTIBURST RESPONSE DIFFERENTIAL GAIN MAX7446 toc07 120 SUPPLY CURRENT (mA) MAX7446 4-Channel Video Filter for RGB and CVBS Video IN_ 250mV/div 1st 2nd 3rd 4th 5th 6th DIFFERENTIAL PHASE OUT_ 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 250mV/div 1st 2nd 3rd 4th 5th 6th 10µs/div Pin Description PIN NAME 1 INA FUNCTION 2 INB Channel B Video Input. Use channel B for the red (R) signal. AC-couple INB with a series 0.1µF capacitor. 3 INC Channel C Video Input. Use channel C for the green (G) (without sync) signal. AC-couple INC with a series 0.1µF capacitor. 4 IND Channel D Video Input. Use channel D for the blue (B) signal. AC-couple IND with a series 0.1µF capacitor. 5 DISABLE Disable Logic Input. A logic-low on DISABLE enables the output buffers. A logic-high on DISABLE disables all output buffers and puts them in a high-impedance state. 6–9 GND Ground 10 VCC +5V Supply Input 11 OUTD Channel D Video Output. This output can be either AC- or DC-coupled. 12 OUTC Channel C Video Output. This output can be either AC- or DC-coupled. 13 OUTB Channel B Video Output. This output can be either AC- or DC-coupled. 14 OUTA Channel A Video Output. This output can be either AC- or DC-coupled. Channel A Video Input. Use channel A for the CVBS video signal. AC-couple INA with a series 0.1µF capacitor. Detailed Description The MAX7446 filters and buffers video-encoder DAC outputs in applications such as set-top boxes, harddisk recorders, DVD players, and digital VCRs. The MAX7446 reconstructs and cleans up analog video signals from the output of DAC video encoders. Each channel consists of a lowpass filter and an output video buffer that drives two standard 150Ω video loads. 4 The MAX7446 is designed to process CVBS, R, G, and B video signals. The video signal processed by channel A (CVBS) must include a sync pulse. This sync pulse provides the required timing to all four channels. This device operates from a single +5V supply and has a nominal cutoff frequency of 5MHz optimized for NTSC, PAL, and SDTV. _______________________________________________________________________________________ 4-Channel Video Filter for RGB and CVBS Video Filter Response The reconstruction filter consists of two 2nd-order SallenKey stages. The Butterworth-type response features a maximally flat passband for NTSC and PAL bandwidths. The stopband offers at least 43dB (typ) of attenuation at a video-encoder DAC sampling frequency of 27MHz (see the Typical Operating Characteristics). High-Frequency Boost The +1.2dB high-frequency boost on channel A increases image sharpness by compensating for signal degradation and roll-off in the video encoder. Channels B, C, and D (RGB) do not boost high-frequency signals and have a flat response over the video bandwidth. Output Buffers Each output buffer has a fixed gain of +6dB and can drive two 150Ω video loads with a 2VP-P signal. The MAX7446 can drive an AC load or drive the video load directly without using a large output capacitor. The output buffers drive DC loads with an output blanking level of less than 1V. Output Clamp Level When a sync pulse is detected on channel A, the DC restore loop is activated. The function of the loop is to set the DC value of the video signal to a specified voltage. See Table 1 for clamp levels. Applications Information Input Considerations Use 0.1µF ceramic capacitors to AC-couple the inputs. These input capacitors store a DC level so the outputs are clamped to an appropriate DC voltage level. Output Considerations The outputs are typically connected to a 75Ω series back-match resistor followed by the video cable. Because of the inherent divide-by-two of this configuration, the voltage on the video cable is always less than 1V, complying with industry-standard video requirements such as the European SCART standard (which allows up to 2V of DC on the video cable). The video buffer can also drive an AC-coupled video load. Good video performance is achieved with an output capacitor as low as 220µF. Power-Supply Bypassing and Layout The MAX7446 operates from a single +5V supply. Bypass VCC to GND with a 0.1µF capacitor. Place all external components as close to the device as possible. Exposed Pads The TSSOP-EP package has an exposed pad on the bottom of the package. This pad is electrically connected to GND and should be connected to the ground plane for improved thermal conductivity. Do not route signals under this package. Pin Configuration Table 1. Output Clamp Level CHANNEL CLAMP LEVEL (V) A 0.8 B 1.4 C 1.4 D 1.4 TOP VIEW INA 1 14 OUTA INB 2 13 OUTB INC 3 12 OUTC IND 4 MAX7446 11 OUTD 10 VCC DISABLE 5 GND 6 9 GND GND 7 8 GND TSSOP Chip Information TRANSISTOR COUNT: 6300 PROCESS: BiCMOS _______________________________________________________________________________________ 5 MAX7446 Filter Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) TSSOP 4.4mm BODY.EPS MAX7446 4-Channel Video Filter for RGB and CVBS Video Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.