(MAX7462 / MAX7463) Single-Channel Video Reconstruction Filters and Buffers

19-3790; Rev 1; 9/05 Single-Channel Video Reconstruction Filters and Buffers General Description The MAX7462/MAX7463 single-channel, standard-definition, integrated video reconstruction filters and buffers are ideal for anti-aliasing and digital-to-analog smoothing video applications or wherever analog video is reconstructed from digital data (such as cable/satellite/terrestrial set-top boxes and DVRs). The MAX7462 includes a disable function, which places the output in a high-impedance state allowing multiplexing of multiple output signals. It also has an external gain control that sets the output buffer gain to either +6dB or +9.5dB. The higher gain setting allows a lower DAC output signal than the standard 1VP-P signal. The MAX7463 output buffer has a fixed gain of +6dB. The MAX7462/MAX7463 operate from a single +5V supply and have a flat passband out to 5MHz with a stopband attenuation of -43dB (typ) at 27MHz. These devices can drive two standard 150Ω AC-coupled or DC-coupled video loads. The output black level of the MAX7462/MAX7463 is less than 1V for DC-coupled outputs. www.DataSheet4U.com Features ♦ Standard-Definition CVBS Video Reconstruction Filters and Buffers ♦ Passband: -0.05dB at 5MHz ♦ Stopband: -43dB at 27MHz ♦ Selectable Gain: +6dB and +9.5dB (MAX7462) ♦ Output Disable (MAX7462) ♦ Drives 2VP-P into Two 150Ω Video Loads ♦ Output Black Level < 1V for DC-Coupled Output ♦ Very Small µMAX and SO Packages MAX7462/MAX7463 Ordering Information PART MAX7462UUA* MAX7462USA MAX7463USA PINPACKAGE 8 µMAX 8 SO 8 SO BUFFER GAIN (dB) +6/+9.5 selectable +6/+9.5 selectable +6 fixed OUTPUT DISABLE Yes Yes No The MAX7462 is available in an 8-pin µMAX® package and an 8-pin SO package. The MAX7463 is available in an 8-pin SO package. All devices are specified over the 0°C to +85°C temperature range. Applications Cable/Satellite/Terrestrial Set-Top Boxes DVRs Hard-Disk Recorders Note: All parts are specified over the 0°C to +85°C temperature range. *Future product—contact factory for availability. Pin Configurations appear at end of data sheet. Functional Diagram +5V VCC MAX7462 75Ω * 220µF ZO = 75Ω 0.1µF DAC IN LOWPASS FILTER +6dB/+9.5dB OUT 75Ω 75Ω * 220µF ZO = 75Ω GND GAIN *OPTIONAL DISABLE 75Ω µMAX is a registered trademark of Maxim Integrated Products, Inc. ________________________________________________________________ Maxim Integrated Products 1 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. Single-Channel Video Reconstruction Filters and Buffers MAX7462/MAX7463 ABSOLUTE MAXIMUM RATINGS VCC to GND ........................................................................+6.0V All Other Pins to GND ...-0.3V to the lower of (VCC + 0.3V) and +6V Maximum Current into Any Pin Except VCC and GND .....±50mA Continuous Power Dissipation (TA = +70°C) 8-Pin µMAX (derate 4.5mW/°C above +70°C) …...... 362mW 8-Pin SO (derate 5.9mW/°C above +70°C) .......... 470.6mW Operating Temperature Range...............................0°C to +85°C Storage Temperature Range .............................-65°C to +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, CIN = 0.1µF, gain = +6dB, DISABLE = VCC (MAX7462), TA =TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, and TA = +25°C.) PARAMETER Passband Response Stopband Attenuation Output Dynamic Swing Output Sync Tip Clamp Level Group Delay Deviation Differential Gain Differential Phase Signal-to-Noise Ratio Low-Frequency Gain Accuracy Line Time Distortion Field Time Distortion Power-Supply Rejection Ratio Supply Current f ≥ 27MHz Gain = GND (MAX7462) After termination (Note 1) f = 100kHz to 4.2MHz Five-step modulated staircase Five-step modulated staircase Output signal (2VP-P) to RMS noise (100Hz to 5MHz) f =100kHz, relative to a gain of +6dB 18µs, 100 IRE bar 130 lines, 18µs, 100 IRE bar VIN = 100mVP-P, f = 100kHz No load -3 0.1 0.1 35 25 35 0.30 CONDITIONS f = 100kHz to 5MHz, relative to 100kHz MIN -0.65 39 TYP -0.05 43 2.0 0.45 11 0.15 0.15 75 +3 2.4 0.55 MAX +0.65 UNITS dB dB VP-P V ns % Degrees dB % % % dB mA Note 1: Measured after 75Ω back-match resistor. Assume a 75Ω termination resistor. 2 _______________________________________________________________________________________ Single-Channel Video Reconstruction Filters and Buffers Typical Operating Characteristics (VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω, CIN = 0.1µF, gain = +6dB, DISABLE = VCC (MAX7462), TA =TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, and TA = +25°C.) PASSBAND AMPLITUDE vs. FREQUENCY AMPLITUDE vs. FREQUENCY 0 MAX7462/63 toc01 MAX7462/MAX7463 1.5 1.0 AMPLITUDE (dB) 0.5 0 -0.5 -1.0 -1.5 AMPLITUDE (dB) -20 -40 -60 NORMALIZED TO 0dB -80 0.1 1 10 100 FREQUENCY (MHz) NORMALIZED TO 0dB -2.0 0.1 1 FREQUENCY (MHz) 10 PHASE RESPONSE vs. FREQUENCY MAX7462/63 toc03 GROUP DELAY vs. FREQUENCY MAX7462/63 toc04 200 150 100 PHASE (DEGREES) 50 0 -50 -100 100 90 GROUP DELAY (ns) 80 70 60 -150 -200 0.1 1 FREQUENCY (MHz) 10 50 0.1 1 FREQUENCY (MHz) 10 2T RESPONSE MAX7462/63 toc05 MODULATED 12.5T RESPONSE MAX7462/63 toc06 OUT 250mV/div IN 250mV/div 200ns/div 200ns/div _______________________________________________________________________________________ MAX7462/63 toc02 2.0 OUT 250mV/div IN 250mV/div 3 Single-Channel Video Reconstruction Filters and Buffers MAX7462/MAX7463 Typical Operating Characteristics (continued) (VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω, CIN = 0.1µF, gain = +6dB, DISABLE = VCC (MAX7462), TA =TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, and TA = +25°C.) SUPPLY CURRENT vs. TEMPERATURE MAX7462/63 toc07 DIFFERENTIAL GAIN DIFFERENTIAL GAIN (%) 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 1 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 1 2 3 4 5 6 7 2 3 4 5 6 7 MAX7462/63 toc08 40 VIN = +2V NO LOAD SUPPLY CURRENT (mA) 30 20 10 0 17 34 51 68 85 TEMPERATURE (°C) DIFFERENTIAL PHASE (deg) DIFFERENTIAL PHASE MULTIBURST RESPONSE MAX7462/63 toc09 OUT RESPONSE TO A FIELD SQUARE WAVE MAX7462/63 toc10 OUT 250mV/div OUT 500mV/div IN 250mV/div IN 500mV/div 10µs/div 2ms/div DISABLE TURN-ON TIME MAX7462/63 toc11 DISABLE TURN-OFF TIME MAX7462/63 toc12 OUT 1V/div OUT 1V/div GND GND DISABLE 2V/div GND 100ns/div DISABLE 2V/div GND 100ns/div 4 _______________________________________________________________________________________ Single-Channel Video Reconstruction Filters and Buffers Pin Description PIN MAX7462 1 2 3, 4, 5 — 6 7 8 MAX7463 1 — 3 2, 4, 5, 6 — 7 8 NAME IN GAIN GND N.C. DISABLE VCC OUT FUNCTION Video Input. AC-couple IN with a series 0.1µF capacitor. Gain Control Input. Connect GAIN to GND for a gain of +6dB (+2V/V). Connect GAIN to VCC for a gain of +9.5dB (+3V/V). Ground No Connection. Not internally connected. Connect to GND for better performance. Disable Input. Connect to VCC to enable the output buffer (normal operation). Connect to GND to put the output buffer in a high-impedance state. +5V Supply Input Buffer Output. This output can be either AC- or DC-coupled. Use at minimum a 220µF capacitor for AC-coupled loads. MAX7462/MAX7463 Detailed Description The MAX7462/MAX7463 filters and buffers the analog CVBS video outputs of DAC video-encoders in applications such as set-top boxes, hard-disk recorders, DVD players, and digital VCRs. The MAX7462/MAX7463 consist of a lowpass filter and an output video buffer that can drive two standard 150Ω video loads. These devices operate from a single +5V supply and have a bandwidth optimized for interlaced NTSC, PAL, and SDTV. capacitor. The output buffer can drive DC loads while maintaining an output blanking level of less than 1V. The blanking level allows the MAX7462/MAX7463 to meet the digital TV interface specifications for DC coupling. Applications Information Input Considerations Use a 0.1µF ceramic capacitor to AC-couple the input. The input capacitor stores a DC voltage so that the output is clamped to the appropriate DC voltage level. Filter The reconstruction filter is a 4th-order Butterworth-type response that features a maximally flat passband for NTSC and PAL bandwidths. The stopband attenuation is optimized for a video-encoder DAC sampling frequency of 27MHz (see the Typical Operating Characteristics). 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 blanking level on the video cable is always less than 1V, complying with industry-standard video requirements such as the digital TV standard (which allows up to 1VDC on the video cable) and the European SCART standard (which allows up to 2VDC 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. Output Buffer The output buffer can drive two 150Ω video loads with a 2VP-P signal. For the MAX7462, the output buffer gain is selectable between +6dB and +9.5dB by using GAIN (see Table 1). The MAX7463 has a fixed gain of +6dB. The MAX7462/MAX7463 can drive an AC load or drive the video load directly without using a large output Power-Supply Bypassing and Layout The MAX7462/MAX7463 operate from a single +5V supply. Bypass VCC to GND with a 0.1µF capacitor. In a