19-0995; Rev 0; 9/07 KIT ATION EVALU E L B A IL AVA 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect Operating at 1.8V from a single power supply, the MAX9516 amplifies standard-definition video signals and only consumes 6mW quiescent power and 12mW average power. The MAX9516 leverages Maxim's DirectDriveTM technology. Combining DirectDrive with the external positive 1.8V supply, the MAX9516 is able to drive a 2VP-P video signal into a 150 load. The MAX9516 has the ability to detect and report the presence of a video load and reduce power consumption when the load is not present. The MAX9516 can detect the presence of a video load and report a change in load through the LOAD flag. This feature helps reduce overall system power consumption because the video encoder and the MAX9516 only need to be turned on when a video load is connected. If no load is connected, the MAX9516 is placed in an active-detect mode and only consumes 31W. Maxim's DirectDrive technology eliminates large outputcoupling capacitors and sets the output video black level near ground. DirectDrive requires an integrated charge pump and an internal linear regulator to create a clean negative power supply so that the amplifier can pull the sync below ground. The charge pump injects so little noise into the video output that the picture is visibly flawless. The MAX9516 features an internal reconstruction filter that smoothes the steps and reduces the spikes on the video signal from the video digital-to-analog converter (DAC). The reconstruction filter typically has 1dB passband flatness of 7.5MHz, and 46dB (typ) attenuation at 27MHz. The input of the MAX9516 can be directly connected to the output of a video DAC. The MAX9516 also features a transparent input sync-tip clamp, allowing AC-coupling of input signals with different DC biases. The MAX9516 has an internal fixed gain of 8. The input full-scale video signal is nominally 0.25VP-P, and the output full-scale video signal is nominally 2VP-P. Applications Digital Still Cameras (DSC) Digital Video Cameras (DVC) Mobile Phones Portable Media Players (PMP) Security/CCTV Cameras Automotive Applications Features o 1.8V or 2.5V Single-Supply Operation o Low Power Consumption (6mW Quiescent, 12mW Average) o Video Load Detect o Reconstruction Filter with 5.5MHz Passband o DirectDrive Sets Video Output Black Level Near Ground o DC-Coupled Input/Output o Transparent Input Sync-Tip Clamp Ordering Information PART PIN-PACKAGE MAX9516ALB+T PKG CODE TOP MARK L1022+1 AAN 10 DFN-10 Note: This device operates over the -40C to +125C operating temperature range. +Denotes lead-free package. T = Tape and reel. Block Diagram MAX9516 IN LPF 250mVP-P VIDEO SHDN TRANSPARENT CLAMP SHUTDOWN CIRCUIT LOAD SENSE AV = 8V/V LINEAR REGULATOR LOAD OUT 2VP-P VIDEO 0V CHARGE PUMP Pin Configuration appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX9516 General Description MAX9516 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect ABSOLUTE MAXIMUM RATINGS Duration of OUT Short Circuit to VDD, GND, and VSS .........................................................Continuous Continuous Current IN, SHDN, LOAD .............................................................20mA Continuous Power Dissipation (TA = +70C) 10-Pin DFN (derate 5mW/C above +70C) ...............403mW Operating Temperature Range ............................-40C to +125C Junction Temperature........................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C (Voltages with respect to GND.) VDD ...........................................................................-0.3V to +3V CPGND..................................................................-0.1V to +0.1V IN ................................................................-0.3V to (VDD + 0.3V) OUT .......................(The greater of VSS and -1V) to (VDD + 0.3V) SHDN........................................................................-0.3V to +4V C1P.............................................................-0.3V to (VDD + 0.3V) C1N .............................................................(VSS - 0.3V) to +0.3V VSS............................................................................-3V to +0.3V 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 (VDD = SHDN = +1.8V, GND = 0V, OUT has RL = 150 connected to GND, C1 = C2 = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = 1.8V, TA = +25C.) (Note 1) PARAMETER Supply Voltage Range Supply Current Shutdown Supply Current SYMBOL CONDITIONS VDD Guaranteed by PSRR IDD Amplifier ON, SHDN = VDD ISHDN MIN 1.700 Full operation mode, VIN = 0mV (Note 2) 3.1 Active-detect mode, no load 3 SHDN = GND Output Load Detect Threshold RL to GND Output Level IN = 80mV TYP 0.01 -85 +9 MAX UNITS 2.625 V 5.3 mA A 10 A 200 +85 mV DC-COUPLED INPUT Guaranteed by output-voltage swing Input Voltage Range Input Current Input Resistance IB RIN 1.7V VDD 2.625V 0 262.5 2.375V VDD 2.625V 0 325 mV IN = 130mV 2 10mV IN 250mV 3.5 295 A k AC-COUPLED INPUT Sync-Tip Clamp Level Input-Voltage Swing Sync Crush VCLP CIN = 0.1F Guaranteed by output-voltage swing -8 0 1.7V VDD 2.625V +11 mV 252.5 mVP-P 2.375V VDD 2.625V Percentage reduction in sync pulse at output, RSOURCE = 37.5, CIN = 0.1F 325 1.3 % Input Clamping Current IN = 130mV 2 Line Time Distortion CIN = 0.1F 0.2 % 25 Minimum Input Source Resistance 2 _______________________________________________________________________________________ 3.5 A 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect (VDD = SHDN = +1.8V, GND = 0V, OUT has RL = 150 connected to GND, C1 = C2 = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = 1.8V, TA = +25C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 7.84 8 8.16 V/V 0 VIN 262.5mV, DC-coupled input 2.058 2.1 2.142 0 VIN 252.5mVP-P, AC-coupled input 1.979 2.02 2.061 0 VIN 325mV 2.548 2.6 2.652 48 58 dB 0V IN VDD, SHDN = GND 2.5 M OUT = 0V, -5mA ILOAD +5mA 0.02 Shutdown Output Resistance 0V OUT VDD, SHDN = GND 10.0 OUT Leakage Current SHDN = GND DC CHARACTERISTICS DC Voltage Gain AV Guaranteed by output-voltage swing (Note 3) 1.7V VDD 2.625V Output-Voltage Swing 2.375V VDD 2.625V 1.7V VDD 2.625V, measured between 75 load resistors Power-Supply Rejection Ratio Shutdown Input Resistance Output Resistance ROUT Output Short-Circuit Current M 1 Sourcing 81 Sinking 45 VP-P A mA AC CHARACTERISTICS Standard-Definition Reconstruction Filter OUT = 2VP-P, reference frequency is 100kHz Differential Gain DG Differential Phase DP 1dB passband flatness 7.5 f = 5.5MHz -0.2 f = 8.5MHz -3.0 f = 27MHz -48.7 f = 3.58MHz 1.05 f = 4.43MHz 1.1 f = 3.58MHz 0.4 f = 4.43MHz 0.45 MHz dB % Degrees Group-Delay Distortion 100kHz f 5MHz, OUT = 2VP-P 16 ns Peak Signal to RMS Noise 100kHz f 5MHz 64 dB f = 100kHz, VRIPPLE = 100mVP-P 54 dB 2T Pulse-to-Bar K Rating 2T = 200ns, bar time is 18s, the beginning 2.5% and the ending 2.5% of the bar time is ignored 0.1 K% 2T Pulse Response 2T = 200ns 0.3 K% 2T Bar Response 2T = 200ns, bar time is 18s, the beginning 2.5% and the ending 2.5% of the bar time is ignored 0.1 K% Power-Supply Rejection Ratio PSRR _______________________________________________________________________________________ 3 MAX9516 ELECTRICAL CHARACTERISTICS (continued) ELECTRICAL CHARACTERISTICS (continued) (VDD = SHDN = +1.8V, GND = 0V, OUT has RL = 150 connected to GND, C1 = C2 = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = 1.8V, TA = +25C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Nonlinearity 5-step staircase 0.2 % Output Impedance f = 5MHz, IN = 80mV 7.5 VOUT-to-VIN Isolation SHDN = GND, f 5.5MHz -78 dB VIN-to-VOUT Isolation SHDN = GND, f 5.5MHz -79 dB CHARGE PUMP Switching Frequency 325 625 1150 kHz 0.5 V 10 A LOGIC SIGNALS Logic-Low Threshold VIL SHDN, VDD = 1.7V to 2.625V Logic-High Threshold VIH SHDN, VDD = 1.7V to 2.625V 1.4 V SHDN Logic Input Current IIL, IIH Output High Voltage VOH LOAD, IOH = 3mA Output Low Voltage VOL LOAD, IOL = 3mA VDD 0.4 V 0.4 V Note 1: All devices are 100% production tested at TA = +25C. Specifications over temperature limits are guaranteed by design. Note 2: Supply current does not include current supplied to VOUT load. Note 3: Voltage gain (AV) is a two-point measurement in which the output-voltage swing is divided by the input-voltage swing. Typical Operating Characteristics (VDD = SHDN = 1.8V, GND = 0V, video output has RL = 150 connected to GND, TA = +25C, unless otherwise noted.) 0.5 MAX9516 toc03 0 20 MAX9516 toc02 1.0 MAX9516 toc01 20 LARGE-SIGNAL GAIN vs. FREQUENCY SMALL-SIGNAL GAIN FLATNESS vs. FREQUENCY SMALL-SIGNAL GAIN vs. FREQUENCY 0 0 -40 -20 -0.5 GAIN (dB) GAIN (dB) -20 GAIN (dB) MAX9516 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect -1.0 -1.5 -60 -40 -60 -2.0 -80 -80 -2.5 -100 -100 -3.0 0.1 1 10 FREQUENCY (MHz) 4 VOUT = 2VP-P VOUT = 100mVP-P VOUT = 100mVP-P 100 0.1 1 10 FREQUENCY (MHz) 100 0.1 1 10 FREQUENCY (MHz) _______________________________________________________________________________________ 100 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect GROUP DELAY vs. FREQUENCY 100 90 -0.5 70 -1.0 -20 60 50 -1.5 40 -2.0 30 0 PSSR (dB) 80 DELAY (ns) 0 20 MAX9516 toc05 0.5 -60 20 -2.5 VRIPPLE = 100mVP-P VOUT = 2VP-P 0 -3.0 0.1 1 0.1 100 10 -100 1 100 10 1 10 FREQUENCY (MHz) FREQUENCY (MHz) QUIESCENT SUPPLY CURRENT vs. TEMPERATURE VOLTAGE GAIN vs. TEMPERATURE OUTPUT VOLTAGE vs. INPUT VOLTAGE 8.15 3.5 3.0 2.5 8.10 8.05 8.00 7.95 2.0 7.90 1.5 7.85 -25 0 25 50 75 TEMPERATURE (C) 100 125 100 1.0 0.5 0 -0.5 -1.0 7.80 1.0 1.5 OUTPUT VOLTAGE (V) VOLTAGE GAIN (V/V) 4.0 2.0 MAX9516 toc08 8.20 MAX9516 toc07 4.5 -50 0.1 FREQUENCY (MHz) 5.0 QUIESCENT SUPPLY CURRENT (mA) -80 10 VOUT = 2VP-P -40 MAX9516 toc09 GAIN (dB) 110 MAX9516 toc04 1.0 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX9516 toc06 LARGE-SIGNAL GAIN FLATNESS vs. FREQUENCY -1.5 -50 -25 0 25 50 75 TEMPERATURE (C) 100 125 -100 -50 0 50 100 150 200 250 300 350 400 INPUT VOLTAGE (mV) _______________________________________________________________________________________ 5 MAX9516 Typical Operating Characteristics (continued) (VDD = SHDN = 1.8V, GND = 0V, video output has RL = 150 connected to GND, TA = +25C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = SHDN = 1.8V, GND = 0V, video output has RL = 150 connected to GND, TA = +25C, unless otherwise noted.) 2T RESPONSE DIFFERENTIAL GAIN AND PHASE DIFFERENTIAL GAIN (%) 12.5T RESPONSE MAX9516 toc11 MAX9516 toc10 1.6 MAX9516 toc12 1.2 IN 50mV/div 0.8 0.4 IN 50mV/div 0 -0.4 DIFFERENTIAL PHASE (deg) MAX9516 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect 1.2 0.8 0.4 0 -0.4 -0.8 -1.2 1 2 3 4 5 6 7 0V 0V OUT 400mV/div 0V OUT 400mV/div 0V 1 2 3 4 5 6 100ns/div 7 400ns/div FIELD SQUARE-WAVE (AC-COUPLED) NTC-7 VIDEO TEST SIGNAL MAX9516 toc14 MAX9516 toc13 IN 100mV/div IN 100mV/div 0V 0V OUT 800mV/div 0V 10s/div 6 OUT 800mV/div 0V 2ms/div _______________________________________________________________________________________ 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect PIN NAME FUNCTION 1 VSS 2 C1N Charge-Pump Negative Power Supply. Bypass with a 1F capacitor to GND. 3 CPGND 4 C1P Charge-Pump Flying Capacitor Positive Terminal. Connect a 1F capacitor from C1P to C1N. 5 VDD Positive Power Supply. Bypass with a 0.1F capacitor to GND. 6 LOAD 7 GND 8 IN 9 SHDN 10 OUT Charge-Pump Flying Capacitor Negative Terminal. Connect a 1F capacitor from C1P to C1N. Charge-Pump Ground Load-Detect Output. LOAD goes high when an output video load is detected. Ground Video Input Active-Low Shutdown. Connect to VDD for normal operation. Video Output Detailed Description The MAX9516 represents Maxim's second-generation of DirectDrive video amplifiers, which meet the requirements of current and future portable equipment: * 1.8V operation. Engineers want to eliminate the 3.3V supply in favor of lower supply voltages. * Lower power consumption. The MAX9516 reduces average power consumption by up to 75% compared to the 3.3V first-generation devices (MAX9503/ MAX9505). * Internal fixed gain of 8. As the supply voltages drop for system chips on deep submicron processes, the video DAC can no longer create a 1VP-P signal at its output, and the gain of 2 found in the previous generation of video filter amps is not enough. * Active-detect mode reduces power consumption. DirectDrive technology is necessary for a voltage-mode amplifier to output a 2VP-P video signal from a 1.8V supply. The integrated inverting charge pump creates a negative supply that increases the output range and gives the video amplifier enough headroom to drive a 2VP-P video signal with a 150 load. DirectDrive Background Integrated video filter amplifier circuits operate from a single supply. The positive power supply usually creates video output signals that are level-shifted above ground to keep the signal within the linear range of the output amplifier. For applications where the positive DC level is not acceptable, a series capacitor can be inserted in the output connection in an attempt to elimi- nate the positive DC level shift. The series capacitor cannot truly level-shift a video signal because the average level of the video varies with picture content. The series capacitor biases the video output signal around ground, but the actual level of the video signal can vary significantly depending upon the RC time constant and the picture content. The series capacitor creates a highpass filter. Since the lowest frequency in video is the frame rate, which can be from 24Hz to 30Hz, the pole of the highpass filter should ideally be an order of magnitude lower in frequency than the frame rate. Therefore, the series capacitor must be very large, typically from 220F to 3000F. For spaceconstrained equipment, the series capacitor is unacceptable. Changing from a single-series capacitor to a SAG network that requires two smaller capacitors only reduces space and cost slightly. The series capacitor in the usual output connection also prevents damage to the output amplifier if the connector is shorted to a supply or to ground. While the output connection of the MAX9516 does not have a series capacitor, the MAX9516 will not be damaged if the connector is shorted to a supply or to ground (see the Short-Circuit Protection section). Video Amplifier If the full-scale video signal from a video DAC is 250mV, the black level of the video signal created by the video DAC is approximately 75mV. The MAX9516 shifts the black level to near ground at the output so that the active video is above ground and the sync is below ground. The amplifier needs a negative supply for its output stage to remain in its linear region when driving sync below ground. _______________________________________________________________________________________ 7 MAX9516 Pin Description MAX9516 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect The MAX9516 has an integrated charge pump and linear regulator to create a low-noise negative supply from the positive supply voltage. The charge pump inverts the positive supply to create a raw negative voltage that is then fed into the linear regulator, which filters out the charge-pump noise. Comparison Between DirectDrive Output and AC-Coupled Output The actual level of the video signal varies less with a DirectDrive output than an AC-coupled output. The average video signal level can change greatly depending upon the picture content. With an AC-coupled output, the average level will change according to the time constant formed by the series capacitor and series resistance (usually 150). For example, Figure 1 shows an AC-coupled video signal alternating between a completely black screen and a completely white screen. Notice the excursion of the video signal as the screen changes. With the DirectDrive amplifier, the black level is held at ground. The video signal is constrained between -0.3V and +0.7V. Figure 2 shows the video signal from a DirectDrive amplifier with the same input signal as the AC-coupled system. INPUT 500mV/div OUTPUT 500mV/div 2ms/div Figure 1. AC-Coupled Output INPUT 500mV/div 0V Load Detection The MAX9516 provides a video load detection feature. The device enters active-detect mode when it is enabled (SHDN = VDD). Every 128ms, the part checks for a load by connecting a 7.5k pullup resistor to the video output for 1ms. If the video output is pulled up during the test, then no load is present and LOAD is low. If the video output stays low during the test, then a load is connected and LOAD goes high. The state of LOAD is latched during the sleep time between sense pulses. All load-detect changes are deglitched over a nominal 128ms period. The status of the video load must remain constant during this deglitch period for LOAD to change state. If a load is detected, the part enters the full operation mode and the amplifier, filter, and sync-tip clamp turn on. The part then continually checks if the load is present by sensing the sinking load current. Therefore, a black-burst signal (or output signal < 0V) is required to maintain the detected load status. If the load remains present, the LOAD pin remains high. If the load is removed, LOAD goes low and the part goes back to the active-detect mode in which power consumption is typically 31W. 8 0V OUTPUT 1V/div 2ms/div Figure 2. DirectDrive Output Video Reconstruction Filter The MAX9516 includes an internal five-pole, Butterworth lowpass filter to condition the video signal. The reconstruction filter smoothes the steps and reduces the spikes created whenever the DAC output changes value. In the frequency domain, the steps and spikes cause images of the video signal to appear at multiples of the sampling clock frequency. The reconstruction filter typically has 1dB passband flatness of 7.5MHz and 46dB (typ) attenuation at 27MHz. Transparent Sync-Tip Input Clamp The MAX9516 contains an integrated, transparent sync-tip clamp. When using a DC-coupled input, the sync-tip clamp does not affect the input signal, as long as it remains above ground. When using an AC-cou- _______________________________________________________________________________________ 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect Short-Circuit Protection In Figure 7, the MAX9516 includes a 75 back-termination resistor that limits short-circuit current if an external short is applied to the video output. The MAX9516 also features internal output short-circuit protection to prevent device damage in prototyping and applications where the amplifier output can be directly shorted. Shutdown The MAX9516 features a low-power shutdown mode for battery-powered/portable applications. Shutdown reduces the quiescent current to less than 10nA. Connecting SHDN to ground (GND) disables the output and places the MAX9516 into a low-power shutdown mode. In shutdown mode, the sync-tip clamp, filter, amplifier, charge pump, and linear regulator are turned off and the video output is high impedance. Applications Information Power Consumption The quiescent power consumption and average power consumption of the MAX9516 is remarkably low because of the 1.8V operation and the DirectDrive technology. Quiescent power consumption (PQ) is the power consumed by the internal circuitry of the MAX9516. The formula for calculating PQ is below. PQ = PTOTAL - PLOAD PTOTAL is the total power drawn from the supply voltage, and PLOAD is the power consumed by the load attached to OUT. For the MAX9516, the quiescent power consumption is typically 6mW. Average power consumption, which is representative of the power consumed in a real application, is the total power drawn from the supply voltage for a MAX9516 driving a 150 load to ground with a 50% flat field. Under such conditions, the average power consumption Table 1. Power Consumption of MAX9516 with Different Video Signals MAX9516 POWER CONSUMPTION (mW) VIDEO SIGNAL All Black Screen 6.7 All White Screen 18.2 75% Color Bars 11.6 50% Flat Field 11.7 for the MAX9516 is 12mW. Table 1 shows the power consumption with different video signals. The supply voltage is 1.8V. OUT drives a 150 load to ground. Notice that the two extremes in power consumption occur with a video signal that is all black and a video signal that is all white. The power consumption with 75% color bars and a 50% flat field lies in between the extremes. Interfacing to Video DACs that Produce Video Signals Larger than 0.25VP-P Devices designed to generate 1VP-P video signals at the output of the video DAC can still work with the MAX9516. Most video DACs source current into a ground-referenced resistor, which converts the current into a voltage. Figure 3 shows a video DAC that creates a video signal from 0 to 1V across a 150 resistor. The following video filter amplifier has a gain of 2V/V so that the output is 2VP-P. The MAX9516 expects input signals that are 0.25VP-P nominally. The same video DAC can be made to work with the MAX9516 by scaling down the 150 resistor to a 37.5 resistor, as shown in Figure 4. The 37.5 resistor is one-quarter of the 150 resistor, resulting in a video signal that is one-quarter the amplitude. IMAGE PROCESSOR ASIC 75 0 TO 1V DAC LPF 2V/V 150 Figure 3. Video DAC generates a 1VP-P signal across a 150 resistor connected to ground. _______________________________________________________________________________________ 9 MAX9516 pled input, the sync-tip clamp automatically clamps the input signal to ground, preventing it from going lower. A small current of 2A pulls down on the input to prevent an AC-coupled signal from drifting outside the input range of the part. Using an AC-coupled input will result in some additional variation of the black level at the output. Applying a voltage above ground to the input pin of the device always produces the same output voltage, regardless of whether the input is DC- or AC-coupled. However, since the sync-tip clamp level (VCLP) can vary over a small range, the video black level at the output of the device when using an AC-coupled input can vary by an additional amount equal to the VCLP multiplied by the DC voltage gain (AV). 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516 Anti-Alias Filter The MAX9516 provides anti-alias filtering with buffering before an analog-to-digital converter (ADC), which is present in an NTSC/PAL video decoder, for example. Figure 5 shows an example application circuit. An external composite video signal is applied to VIDIN, which is terminated with a total of 74 (56 and 18 resistors) to ground. The signal is attenuated by four, and then AC-coupled to IN. The normal 1VP-P video signal must be attenuated because with a 1.8V supply, the MAX9516 can handle only a video signal of approximately 0.25VP-P at IN. AC-couple the video signal to IN because the DC level of an external video signal is usually not well specified, although it is reasonable to expect that the signal is between -2V and +2V. The 10 series resistor increases the equivalent source resistance to about 25, which is the minimum necessary for a video source to drive the internal sync-tip clamp. For external video signals larger than 1VP-P, operate the MAX9516 from a 2.5V supply so that IN can accommodate a 0.325VP-P video signal, which is equivalent to a 1.3VP-P video signal at VIDIN. IMAGE PROCESSOR ASIC MAX9516 75 0 TO 0.25V DAC LPF 8V/V 37.5 Figure 4. Video DAC Generates a 0.25VP-P Signal Across a 37.5 Resistor Connected to Ground VDD MAX9516 SHUTDOWN CIRCUIT SHDN VIDIN LOAD SENSE LOAD 56 10 IN LPF VIDEO AMPLIFIER 0.1F 18 CLAMP 1.8V DC LEVEL SHIFT OUT 75 VIDEO DECODER 75 LINEAR REGULATOR VDD CHARGE PUMP 0.1F GND CPGND C1P C1N VSS C1 1F C2 1F Figure 5. MAX9516 Used as an Anti-Alias Filter with Buffer 10 ______________________________________________________________________________________ 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect resistor to ground, then the luma signal usually does not have a positive DC bias, and the sync tip is at approximately ground. When the chroma and luma signals are added together, the resulting composite video signal still has a positive DC bias. Therefore, the signal must be AC-coupled into the MAX9516 because the composite video signal is above the nominal, DC-coupled 0V to 0.25V input range. Video Signal Routing If the chroma DAC has an independent output resistor to ground, then the chroma signal, which is a carrier at 3.58MHz for NTSC or at 4.43MHz for PAL, has a positive DC bias to keep the signal above ground at all times. If the luma DAC has an independent output Minimize the length of the PCB trace between the output of the video DAC and the input of the MAX9516 to reduce coupling of external noise into the video signal. If possible, shield the PCB trace. VDD VIDEO ASIC DAC MAX9516 SHDN LUMA (Y) LOAD SENSE IN LPF 0.1F DAC VIDEO AMPLIFIER CLAMP CHROMA (C) 1.8V LOAD OUT 75 DC LEVEL SHIFT 75 LINEAR REGULATOR VDD CHARGE PUMP 0.1F GND CPGND C1P C1 1F C1N VSS C2 1F Figure 6. Luma (Y) and Chroma (C) Signals Added Together to Create Composite Video Signal (Which is AC-Coupled Into the MAX9516) ______________________________________________________________________________________ 11 MAX9516 Video Source with a Positive DC Bias In some applications, the video source generates a signal with a positive DC voltage bias, i.e., the sync tip of the signal is well above ground. Figure 6 shows an example in which the outputs of the luma (Y) DAC and the chroma (C) DAC are connected together. Since the DACs are current mode, the output currents sum together into the resistor, which converts the resulting current into a voltage representing a composite video signal. MAX9516 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect Using a Digital Supply The MAX9516 was designed to operate from noisy digital supplies. The high PSRR (54dB at 100kHz) allows the MAX9516 to reject the noise from the digital power supplies (see the Typical Operating Characteristics). If the digital power supply is very noisy and stripes appear on the television screen, increase the supply bypass capacitance. An additional, smaller capacitor in parallel with the main bypass capacitor can reduce digital supply noise because the smaller capacitor has lower equivalent series resistance (ESR) and equivalent series inductance (ESL). Power-Supply Bypassing and Ground Management The MAX9516 operates from a 1.7V to 2.625V single supply and requires proper layout and bypassing. For the best performance, place the components as close to the device as possible. Proper grounding improves performance and prevents any switching noise from coupling into the video signal. Bypass the analog supply (VDD) with a 0.1F capacitor to GND, placed as close to the device as possible. Bypass VSS with a 1F capacitor to GND as close to the device as possible. The total system bypass capacitance on VDD should be at least 10F or ten times the capacitance between C1P and C1N. Typical Operating Circuits VDD MAX9516 SHDN VIDEO ASIC LOAD SENSE IN DAC LPF VIDEO AMPLIFIER TRANSPARENT CLAMP 1.8V LOAD OUT DC LEVEL SHIFT 75 LINEAR REGULATOR VDD CHARGE PUMP 0.1F GND CPGND C1P C1 1F C1N VSS C2 1F Figure 7. DC-Coupled Input 12 75 ______________________________________________________________________________________ 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect VDD MAX9516 SHDN VDD VIDEO ASIC LOAD SENSE IN DAC LPF 0.1F VIDEO AMPLIFIER CLAMP OUT DC LEVEL SHIFT LINEAR REGULATOR VDD 1.8V LOAD CHARGE PUMP 0.1F GND CPGND C1P C1 1F C1N VSS C2 1F Figure 8. AC-Coupled Input Chip Information Pin Configuration PROCESS: BiCMOS TOP VIEW OUT SHDN IN 10 9 GND LOAD 8 7 6 4 5 MAX9516 + 1 VSS 2 3 C1N CPGND C1P VDD DFN ______________________________________________________________________________________ 13 MAX9516 Typical Operating Circuits (continued) 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.) A D XXXX XXXX XXXX b e N SOLDER MASK COVERAGE E PIN 1 0.10x45 L PIN 1 INDEX AREA 6, 8, 10L UDFN.EPS MAX9516 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect L1 1 SAMPLE MARKING A A (N/2 -1) x e) 7 CL CL b L A A2 A1 L e EVEN TERMINAL e ODD TERMINAL PACKAGE OUTLINE, 6, 8, 10L uDFN, 2x2x0.80 mm -DRAWING NOT TO SCALE- 14 21-0164 ______________________________________________________________________________________ A 1 2 1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect COMMON DIMENSIONS SYMBOL MIN. NOM. A 0.70 0.75 0.80 A1 0.15 0.20 0.25 0.035 A2 0.020 0.025 D 1.95 2.00 E 1.95 2.00 L 0.30 0.40 L1 MAX. - 2.05 2.05 0.50 0.10 REF. PACKAGE VARIATIONS PKG. CODE N e b (N/2 -1) x e L622-1 6 0.65 BSC 0.300.05 1.30 REF. L822-1 8 0.50 BSC 0.250.05 1.50 REF. L1022-1 10 0.40 BSC 0.200.03 1.60 REF. PACKAGE OUTLINE, 6, 8, 10L uDFN, 2x2x0.80 mm -DRAWING NOT TO SCALE- 21-0164 A 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15 (c) 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX9516 Package Information (continued) (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.)