19-2857; Rev 0; 4/03 KIT ATION EVALU LE B A IL A AV Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND Applications Set-Top Boxes/HDR/DVD Game Consoles Camcorders Composite, Component, S-Video Output for NTSC, PAL, SDTV Features ♦ Back-Porch of Video Output Signal Clamped to Ground ♦ Eliminates Input/Output AC-Coupling Capacitors ♦ 0.1% Line-Time Distortion ♦ Stopband: 55dB at 27MHz ♦ Passband: ±0.8dB out to 5MHz ♦ Diff Gain = 0.05%, Diff Phase = 0.05 Degrees ♦ Output Clamped to Ground with Loss of Input ♦ Each Output Drives Two 150Ω Video Loads ♦ Up to 2dB of High-Frequency Boost Control ♦ Ideal for CVBS, Y/C (S-Video), and RGB (Y, Pb, Pr) Outputs for NTSC, PAL, and SDTV ♦ Filter Bypass Mode ♦ Small 20-Pin 5mm ✕ 5mm Thin QFN Package Ordering Information PART TEMP RANGE PIN-PACKAGE MAX7438ETP -40°C to +85°C 20 Thin QFN-EP* MAX7439ETP -40°C to +85°C 20 Thin QFN-EP* *EP = Exposed paddle Pin Configuration appears at end of data sheet. Functional Diagram ENCODER DAC1 IN1 LOWPASS FILTER GAIN/LEVEL SHIFT IN2 LOWPASS FILTER Z0 = 75Ω Z0 = 75Ω BACK-PORCH DETECTOR DAC2 OUT1 75Ω 75Ω GAIN/LEVEL SHIFT OUT2 75Ω 75Ω Z0 = 75Ω Z0 = 75Ω MAX7438 MAX7439 DAC3 IN3 HFB1 HFB2 HFB3 LOWPASS FILTER 75Ω GAIN/LEVEL SHIFT OUT3 75Ω 75Ω BIAS GENERATOR GND VCC = +5V VSS = -5V 75Ω 75Ω Z0 = 75Ω Z0 = 75Ω HIGH-FREQUENCY BOOST CONTROL/ BYPASS 75Ω 75Ω 75Ω EXT 10kΩ ________________________________________________________________ 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 MAX7438/MAX7439 General Description The MAX7438/MAX7439 three-channel standard definition video reconstruction filters include a back-porch clamp that sets the output blanking level of the video signal to ground. Each channel of the MAX7438/ MAX7439 combines a lowpass filter with adjustable high-frequency boost levels and an output buffer capable of driving two standard 150Ω video loads. The blanking level of the output video signal on each channel is clamped to ground, eliminating the need for large AC-coupling output capacitors. Direct input coupling circuitry eliminates the need for AC-coupling input capacitors. This DC-in/DC-out architecture results in extremely low line-time distortion. The MAX7438/ MAX7439 are ideal for antialiasing and DAC smoothing in digital video devices such as STBs, DVDs, PVRs, and hard disk recorders. The MAX7438/MAX7439 operate from ±5V dual supplies. The three-channel MAX7438/MAX7439 are ideal for Y, Pb, Pr, and RGB component video signals, three composite video signals, and also Y/C plus CVBS video signals. Each filter channel achieves 60dB of attenuation at 27MHz and a maximally flat passband from DC to 5MHz. The MAX7438 offers an internal gain of +2V/V, while the MAX7439 offers a gain of +3V/V. MAX7438/MAX7439 Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V VSS to GND...............................................................-6V to +0.3V OUT_ to GND ........................................................-2.5V to +3.5V All Other Pins to GND ......................(VSS - 0.3V) to (VCC + 0.3V) Maximum Current into Any Pin .........................................±50mA Continuous Power Dissipation (TA = +70°C) 20-Pin 5mm x 5mm Thin QFN (derate 20.8mW/°C above +70°C)...........................................................1666.7mW 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%, VSS = -5V ±5%, REXT = 10kΩ ±1%, RHFB_-1 = 15kΩ ±1%, RHFB_-2 = 1kΩ ±1%, no boost, ROUT = 75Ω, COUT = 0 to 20pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL Passband Response Stopband Attenuation ASB HF Boost Step Size CONDITIONS -0.6 +0.6 -0.8 +0.8 f = 27MHz, relative to 100kHz Total Harmonic Distortion dG dθ THD 60 50 280 360 670 850 1360 1700 Boost 3 2250 2750 3500 VCC 5-step modulated staircase f = 100kHz to 5MHz, VIN = 0.7VP-P MAX7438, VIN = 1VP-P 0.05 0.5 MAX7439, VIN = 670mVP-P 0.05 0.5 MAX7438, VIN = 1VP-P 0.05 0.5 MAX7439, VIN = 670mVP-P 0.05 0.5 MAX7438, VIN = 700mVP-P 0.2 0.5 MAX7439, VIN = 460mVP-P 0.2 0.5 Signal-to-Noise Ratio SNR Output signal (2VP-P) to P-P noise, f = 100Hz to 5MHz Group Delay Deviation ∆tG Deviation from 100kHz to 3.58(4.43)MHz Group Delay Matching tG(MATCH) f = 100kHz dB dB 0 Boost 2 5-step modulated staircase UNITS dB Boost 1 Boost 4 Differential Phase 40 0.45 No boost Differential Gain MAX f = 100kHz to 4.2MHz, no HF boost f = 4.2MHz VHFB_ TYP f = 100kHz to 5MHz, no HF boost Bypass HFB_ Voltage Range MIN mV % Degrees % 68 75 12 2 dB 30 ns ns Line-Time Distortion HDIST 18µs, 100 IRE bar 0.1 % Field-Time Distortion VDIST 130 lines, 18µs, 100 IRE bar 0.2 % 2 _______________________________________________________________________________________ Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND (VCC = +5V ±5%, VSS = -5V ±5%, REXT = 10kΩ ±1%, RHFB_-1 = 15kΩ ±1%, RHFB_-2 = 1kΩ ±1%, no boost, ROUT = 75Ω, COUT = 0 to 20pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN Clamp Accuracy Output blanking level relative to GND Clamp Settling Time Back porch within the specified clamp accuracy Low-Frequency Gain Gain at 100kHz Low-Frequency Gain Matching TYP -55 Input Voltage Range UNITS +55 mV 50 Lines MAX7438 5.5 6 6.5 MAX7439 9 9.54 10 Channel-to-channel gain matching, f = 100kHz tG MAX +5 % V THD < 0.5% -0.5 +1.8 Output Voltage Range VOUT f = 5MHz -0.8 +1.8 Channel-to-Channel Crosstalk XTALK Channel-to-channel crosstalk, f = 5MHz Output Short-Circuit Current ISC Input Leakage Current at IN_ IIN_ Input Leakage Current at HFB_ -60 OUT_ shorted to GND or VCC 50 mA ±5 Bypass mode, boost 1 to boost 3 0.2 Boost 4 30 Input Resistance 500 Supply Voltage Range Supply Current Power-Supply Rejection Ratio µA µA kΩ VCC 4.75 5.25 VSS -4.75 -5.25 ICC VCC = +5.25V, no load 110 160 ISS VSS = -5.25V, no load 110 160 VIN = 100mVP-P, f = 0 to 3.5MHz 30 PSRR V dB ±1 IHFB_ dB V mA dB Typical Operating Characteristics (VCC = +5V, VSS = -5V, ROUT_ = 150Ω, REXT = 10kΩ, no boost, TA = +25°C, unless otherwise noted.) 0 -10 0 -10 -40 -30 -40 -50 -50 -60 -60 -70 -70 NORMALIZED TO 0dB 0.1 1 -80 10 FREQUENCY (MHz) 100 GAIN (dB) -30 -80 2.5 -20 GAIN (dB) GAIN (dB) -20 MAX7438 PASSBAND AMPLITUDE vs. FREQUENCY MAX7438/9 toc02 10 MAX7438/9 toc01 10 MAX7439 AMPLITUDE vs. FREQUENCY 2.0 BOOST 4 1.5 BOOST 3 1.0 BOOST 2 MAX7438/9 toc03 MAX7438 AMPLITUDE vs. FREQUENCY 0.5 0 -0.5 BOOST 1 -1.0 NO BOOST -1.5 -2.0 NORMALIZED TO 0dB NORMALIZED TO 0dB -2.5 0.1 1 10 FREQUENCY (MHz) 100 0.1 1 10 FREQUENCY (MHz) _______________________________________________________________________________________ 3 MAX7438/MAX7439 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VCC = +5V, VSS = -5V, ROUT_ = 150Ω, REXT = 10kΩ, no boost, TA = +25°C, unless otherwise noted.) MAX7438 CHANNEL RESPONSE (BYPASS MODE) 1.0 BOOST 2 0 BOOST 1 -1.0 NO BOOST 0 -10 0.5 -0.5 0 -1.5 -10 GAIN (dB) BOOST 3 10 MAX7438/9 toc05 1.5 10 MAX7438/9 toc04 2.0 BOOST 4 GAIN (dB) GAIN (dB) 2.5 MAX7439 CHANNEL RESPONSE (BYPASS MODE) MAX7438/9 toc06 MAX7439 PASSBAND AMPLITUDE vs. FREQUENCY -20 -20 -30 -30 -40 -40 -2.0 -50 -2.5 1 10 -50 1 10 FREQUENCY (MHz) FREQUENCY (MHz) MAX7438 GROUP DELAY vs. FREQUENCY MAX7439 GROUP DELAY vs. FREQUENCY GROUP DELAY (ns) 100 120 80 60 60 20 20 0 1 10 1 DIFFERENTIAL PHASE 2T RESPONSE 0.03 -0.02 -0.01 -0.02 0.00 -0.04 0.01 -0.02 -0.04 -0.01 0.2 0.1 0.0 -0.1 1ST 10 2ND 3RD 4TH 0.1 0.0 IN_ 200mv/div IN_ 200mv/div OUT_ 200mv/div OUT_ 200mv/div -0.1 -0.2 -0.3 1ST 4 2ND 3RD 4TH 5TH 6TH 200ns/div 5TH 6TH 12.5T RESPONSE MAX7438/9 toc11 0.00 0.03 MAX7438/9 toc10 FREQUENCY (MHz) 0.2 0.3 -0.3 0.1 FREQUENCY (MHz) 0.3 100 -0.2 0 0.1 10 DIFFERENTIAL GAIN 80 40 1 FREQUENCY (MHz) 100 40 NORMALIZED TO 0dB 0.1 DIFFERENTIAL GAIN (%) 120 100 MAX7438/9 toc08 140 MAX7438/9 toc07 140 GROUP DELAY (ns) NORMALIZED TO 0dB 0.1 MAX7438/9 toc12 0.1 MAX7438/9 toc09 NORMALIZED TO 0dB DIFFERENTIAL PHASE (DEGREES) MAX7438/MAX7439 Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND 400ns/div _______________________________________________________________________________________ Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND 35 0 -35 ISS -70 3.0 -20 CROSSTALK (dB) ICC VCC = +5V VSS = -5V 0 MAX7438/9 toc14 70 3.5 OUTPUT IMPEDANCE (Ω) 105 2.5 2.0 1.5 1.0 -40 -60 -80 0.5 -105 -140 -100 0 10 35 60 85 0.1 TEMPERATURE (°C) 0.1 10 1 1 BACK-PORCH CLAMP VOLTAGE vs. TEMPERATURE BACK-PORCH LEVEL OUTPUT VOLTAGE vs. INPUT VOLTAGE 75 50 25 0 -25 -50 -75 -100 50 MAX7438/9 toc17 100 10 FREQUENCY (MHz) FREQUENCY (MHz) BACK-PORCH CLAMP VOLTAGE (mV) -15 MAX7438/9 toc16 -40 OUTPUT VOLTAGE (mV) SUPPLY CURRENT (mA) 4.0 MAX7438/9 toc13 140 PASSBAND CHANNEL-TO-CHANNEL CROSSTALK vs. FREQUENCY OUTPUT SOURCE IMPEDANCE vs. FREQUENCY MAX7438/9 toc15 SUPPLY CURRENT VS. TEMPERATURE 25 0 -25 -50 -0.2 0.1 0.4 0.7 1.0 INPUT VOLTAGE (V) 1.3 1.6 -40 -15 10 35 60 85 TEMPERATURE (°C) _______________________________________________________________________________________ 5 MAX7438/MAX7439 Typical Operating Characteristics (continued) (VCC = +5V, VSS = -5V, ROUT_ = 150Ω, REXT = 10kΩ, no boost, TA = +25°C, unless otherwise noted.) Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND MAX7438/MAX7439 Pin Description PIN NAME 1, 4, 7, 10, 11, 13, 15, 19 GND 2 IN1 3 HFB1 5 OUT1 6 VCC 8 OUT2 FUNCTION Ground Channel 1 Video Input Channel 1 High-Frequency Boost and Filter Bypass Control Input. Connect external resistors to HFB1 for high-frequency boost and filter bypass control. See Table 1. Channel 1 Video Output +5V Power Input Channel 2 Video Output 9 VSS 12 OUT3 -5V Power Input. Connect the backside exposed pad to VSS. Channel 3 Video Output 14 HFB3 Channel 3 High-Frequency Boost and Filter Bypass Control Input. Connect external resistors to HFB3 for high-frequency boost and filter bypass control. See Table 1. 16 IN3 17 HFB2 Channel 3 Video Input Channel 2 High-Frequency Boost and Filter Bypass Control Input. Connect external resistors to HFB2 for high-frequency boost and filter bypass control. See Table 1. 18 IN2 Channel 2 Video Input 20 EXT External Bias Resistor. Connect a 10kΩ resistor from EXT to GND. — EP Exposed Paddle. Connect to VSS. Do not connect to GND. Table 1. External Resistor Values for Bypass Mode and High-Frequency Boost Control MODE RHFB_-1 (kΩ) RHFB_-2 (kΩ) VHFB_ (V) (VCC = 5V) NOMINAL BOOST (dB)/ BYPASS (MAX7438) NOMINAL BOOST (dB)/ BYPASS (MAX7439) Bypass Bypass Open 0 0 Bypass No boost 15 1 0.318 0 0 Boost 1 11.3 2 0.758 0.5 0.75 Boost 2 16.5 7.32 1.53 1.0 1.5 Boost 3 11.3 11.3 2.5 1.5 2.25 Boost 4 4.42 18.2 4.027 2.0 3.0 Detailed Description Filter The autotrimming circuit digitally controls the corner frequency to maintain the frequency characteristics over process and temperature. Filter Response The MAX7438/MAX7439 reconstruction filters consist of three separate lowpass filters with Butterworth-type response. The filter features a maximally flat passband for NTSC and PAL bandwidths, while maintaining good group delay characteristics. The stopband offers excellent attenuation at frequencies of 27MHz and above (see the Typical Operating Characteristics section). High-Frequency Boost The high-frequency boost compensates for signal degradation and roll-off in the signal path prior to the MAX7438/MAX7439 to increase image sharpness. Program the level of high-frequency boost for each channel by selecting the corresponding external resistor values (R HFB_-1 and R HFB_-2 , as shown in the Typical Operating Circuit section) given in Table 1. The 6 _______________________________________________________________________________________ Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND MAX7438/MAX7439 ACTIVE VIDEO BACK PORCH FRONT PORCH BLACK LEVEL (SETUP) BLANK LEVEL COLOR BURST H-SYNC TIP Figure 1. Standard Video Signal external resistors form a voltage-divider between VCC and GND. The values in the fourth column (VHFB_ (V)) are calculated using the following equation: VHFB_ = VCC x RHFB_-2 / (RHFB_-1 + RHFB_-2) where VCC = 5V. Apply an external voltage to HFB_ in place of RHFB_-1 and R HFB_-2 as an alternative. See the Electrical Characteristics section. Filter boost modes can also be controlled from a microprocessor. See the Applications Information section. Filter Bypass The MAX7438/MAX7439 offer selectable filter bypassing that allows any of the video inputs to be filtered or unfiltered. Select the filter bypass mode for a given channel by setting the corresponding values for RHFB_-1 and RHFB_-2 according to Table 1. Output Buffer The output buffer is able to drive two standard 150Ω video loads with a 2VP-P signal. The MAX7438 output buffer has a preset gain of 2V/V, and the MAX7439 output buffer has a gain of 3V/V. The MAX7439 is ideal for a DAC output whose voltage range is between 0.67V and 1V. Set the DAC output to 0.67V to achieve a 2V/V signal on OUT_. Back-Porch Clamp The MAX7438/MAX7439 feature a back-porch clamp to set the output blanking level. This clamp shifts the DC level of the video signal so that the back-porch level is close to ground (see Figure 1). The devices sense the voltage during back porch and feed back into a control system that provides the appropriate DC-level shift in the filter channel to clamp the output to ground. The back-porch clamp to ground eliminates the need for large output-coupling capacitors that can introduce unwanted line-time distortion (tilt), cost, and board space. This feedback network and the on-chip capacitors introduce a finite settling time (50 lines max) after power-up or any dramatic shift in input voltage (see the Electrical Characteristics section). Channel 1 requires a video signal with sync information (CVBS, Y, or G), since the other two channels are clamped from channel 1. In the absence of a sync on channel 1, the circuit forces all outputs actively and continuously to ground. Applications Information Power-Supply Bypassing and Layout The MAX7438/MAX7439 operate from dual ±5V supplies. Bypass VCC and VSS to GND with 0.1µF capacitors in parallel with 1µF capacitors. Place the 0.1µF capacitors as close to the power inputs as possible. Since EXT is a sensitive input, place REXT close to the device to avoid signals coupling into EXT. Do not route any input, output, or dynamic signal near this pin and the accompanying trace. Note: The exposed paddle is electrically connected to VSS. Do not connect the exposed paddle to ground. Refer to the MAX7438 EV kit for layout examples, as well as a proven PC board layout example. _______________________________________________________________________________________ 7 Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND MAX7438/MAX7439 Typical Operating Circuit ENCODER DAC3 VCC RT RHFB2-1 DAC2 RT RHFB2-2 10kΩ VCC EXT DAC1 RT IN2 HFB2 RHFB3-1 HFB3 IN1 VCC IN3 RHFB3-2 RHFB1-1 HFB1 MAX7438 MAX7439 Z0 = 75Ω OUT3 75Ω RHFB1-2 75Ω Z0 = 75Ω 75Ω Z0 = 75Ω OUT1 75Ω 75Ω VCC GND 75Ω 8 VSS OUT2 Z0 = 75Ω 75Ω 75Ω 1µF 0.1µF 0.1µF VCC = +5V 1µF VSS = -5V Z0 = 75Ω 75Ω 75Ω Z0 = 75Ω 75Ω 75Ω Microprocessor Control of High-Frequency Boost and Bypass Use a DAC output to control the bypass and high-frequency boost levels on each channel (see Figure 2). Set the DAC output voltage to the corresponding bypass or boost levels desired (see Table 1). MAX7438 MAX7439 DAC HFB_ Figure 2. DAC Control of High-Frequency Boost and Bypass 8 _______________________________________________________________________________________ Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND EXT GND IN2 HFB2 IN3 19 18 17 16 9 10 *CONNECT EXPOSED PADDLE TO VSS VSS 5 GND OUT1 8 4 OUT2 3 GND 7 HFB1 MAX7438 MAX7439 6 2 VCC IN1 GND 1 20 TOP VIEW GND Chip Information TRANSISTOR COUNT: 6418 PROCESS: BiCMOS 15 GND 14 HFB3 13 GND 12 OUT3 11 GND 5mm ✕ 5mm THIN QFN _______________________________________________________________________________________ 9 MAX7438/MAX7439 Pin Configuration 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.) D2 0.15 C A D b CL 0.10 M C A B D2/2 D/2 PIN # 1 I.D. QFN THIN.EPS MAX7438/MAX7439 Triple-Channel Video Reconstruction Filters with Back-Porch Clamp to GND k 0.15 C B PIN # 1 I.D. 0.35x45 E/2 E2/2 CL (NE-1) X e E E2 k L DETAIL A e (ND-1) X e CL CL L L e e 0.10 C A C 0.08 C A1 A3 PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE 16, 20, 28, 32L, QFN THIN, 5x5x0.8 mm APPROVAL COMMON DIMENSIONS DOCUMENT CONTROL NO. REV. 21-0140 C 1 2 EXPOSED PAD VARIATIONS NOTES: 1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994. 2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES. 3. N IS THE TOTAL NUMBER OF TERMINALS. 4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE. 5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm FROM TERMINAL TIP. 6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY. 7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION. 8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS. 9. DRAWING CONFORMS TO JEDEC MO220. 10. WARPAGE SHALL NOT EXCEED 0.10 mm. PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE 16, 20, 28, 32L, QFN THIN, 5x5x0.8 mm APPROVAL DOCUMENT CONTROL NO. REV. 21-0140 C 2 2 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. 10 ____________________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.