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19-0995; Rev 0; 9/07
KIT ATION EVALU ILABLE AVA
1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
General Description 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
MAX9516
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.
Ordering Information
PART MAX9516ALB+T PIN-PACKAGE 10 DFN-10 PKG CODE L1022+1 TOP MARK AAN
Note: This device operates over the -40C to +125C operating temperature range. +Denotes lead-free package. T = Tape and reel.
Block Diagram
MAX9516
LOAD SENSE
LOAD
IN LPF 250mVP-P VIDEO
AV = 8V/V
OUT
Applications
Digital Still Cameras (DSC) Digital Video Cameras (DVC) Mobile Phones Portable Media Players (PMP) Security/CCTV Cameras Automotive Applications
TRANSPARENT CLAMP
LINEAR REGULATOR
2VP-P VIDEO 0V
SHDN
SHUTDOWN CIRCUIT
CHARGE PUMP
Pin Configuration appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
ABSOLUTE MAXIMUM RATINGS
(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 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
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 SYMBOL VDD CONDITIONS Guaranteed by PSRR Amplifier ON, SHDN = VDD SHDN = GND RL to GND IN = 80mV 1.7V VDD 2.625V 2.375V VDD 2.625V -85 +9 Full operation mode, VIN = 0mV (Note 2) Active-detect mode, no load MIN 1.700 3.1 3 0.01 10 200 +85 TYP MAX 2.625 5.3 UNITS V mA A A mV
Supply Current
IDD
Shutdown Supply Current Output Load Detect Threshold Output Level DC-COUPLED INPUT Input Voltage Range Input Current Input Resistance AC-COUPLED INPUT Sync-Tip Clamp Level Input-Voltage Swing
ISHDN
Guaranteed by output-voltage swing IB RIN VCLP IN = 130mV 10mV IN 250mV CIN = 0.1F Guaranteed by output-voltage swing
0 0 2 295 -8 0
262.5 mV 325 3.5 A k +11 252.5 mVP-P 325 1.3 2 0.2 25 3.5 % A % mV
1.7V VDD 2.625V 2.375V VDD 2.625V
Sync Crush Input Clamping Current Line Time Distortion Minimum Input Source Resistance
Percentage reduction in sync pulse at output, RSOURCE = 37.5, CIN = 0.1F IN = 130mV CIN = 0.1F
2
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
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 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 Power-Supply Rejection Ratio Shutdown Input Resistance Output Resistance Shutdown Output Resistance OUT Leakage Current Output Short-Circuit Current AC CHARACTERISTICS 1dB passband flatness Standard-Definition Reconstruction Filter OUT = 2VP-P, reference frequency is 100kHz f = 5.5MHz f = 8.5MHz f = 27MHz Differential Gain Differential Phase Group-Delay Distortion Peak Signal to RMS Noise Power-Supply Rejection Ratio 2T Pulse-to-Bar K Rating 2T Pulse Response 2T Bar Response PSRR DG DP f = 3.58MHz f = 4.43MHz f = 3.58MHz f = 4.43MHz 100kHz f 5MHz, OUT = 2VP-P 100kHz f 5MHz f = 100kHz, VRIPPLE = 100mVP-P 2T = 200ns, bar time is 18s, the beginning 2.5% and the ending 2.5% of the bar time is ignored 2T = 200ns 2T = 200ns, bar time is 18s, the beginning 2.5% and the ending 2.5% of the bar time is ignored 7.5 -0.2 -3.0 -48.7 1.05 1.1 0.4 0.45 16 64 54 0.1 0.3 0.1 % Degrees ns dB dB K% K% K% dB MHz ROUT 0 VIN 262.5mV, DC-coupled input 0 VIN 252.5mVP-P, AC-coupled input 0 VIN 325mV 7.84 2.058 1.979 2.548 48 8 2.1 2.02 2.6 58 2.5 0.02 10.0 1 81 45 8.16 2.142 2.061 2.652 dB M M A mA VP-P V/V SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX9516
1.7V VDD 2.625V, measured between 75 load resistors 0V IN VDD, SHDN = GND OUT = 0V, -5mA ILOAD +5mA 0V OUT VDD, SHDN = GND SHDN = GND Sourcing Sinking
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
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 Nonlinearity Output Impedance VOUT-to-VIN Isolation VIN-to-VOUT Isolation CHARGE PUMP Switching Frequency LOGIC SIGNALS Logic-Low Threshold Logic-High Threshold Logic Input Current Output High Voltage Output Low Voltage VIL VIH IIL, IIH VOH VOL SHDN, VDD = 1.7V to 2.625V SHDN, VDD = 1.7V to 2.625V SHDN LOAD, IOH = 3mA LOAD, IOL = 3mA VDD 0.4 0.4 1.4 10 0.5 V V A V V 325 625 1150 kHz SYMBOL CONDITIONS 5-step staircase f = 5MHz, IN = 80mV SHDN = GND, f 5.5MHz SHDN = GND, f 5.5MHz MIN TYP 0.2 7.5 -78 -79 MAX UNITS % dB dB
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.)
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX9516 toc01
SMALL-SIGNAL GAIN FLATNESS vs. FREQUENCY
0.5 0
MAX9516 toc02
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX9516 toc03
20 0 -20 GAIN (dB)
1.0
20 0 -20 GAIN (dB) -40 -60 -80
-40 -60 -80 VOUT = 100mVP-P -100 0.1 1 10 100 FREQUENCY (MHz)
GAIN (dB)
-0.5 -1.0 -1.5 -2.0 -2.5 VOUT = 100mVP-P -3.0 0.1 1 10 100 FREQUENCY (MHz)
VOUT = 2VP-P -100 0.1 1 10 100 FREQUENCY (MHz)
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
Typical Operating Characteristics (continued)
(VDD = SHDN = 1.8V, GND = 0V, video output has RL = 150 connected to GND, TA = +25C, unless otherwise noted.)
MAX9516
LARGE-SIGNAL GAIN FLATNESS vs. FREQUENCY
MAX9516 toc04
GROUP DELAY vs. FREQUENCY
MAX9516 toc05
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY
MAX9516 toc06
1.0 0.5 0
110 100 90 80 DELAY (ns) 60 50 40 30 20 70
20 0 -20 PSSR (dB) -40 -60 -80
GAIN (dB)
-0.5 -1.0 -1.5 -2.0 -2.5 VOUT = 2VP-P -3.0 0.1 1 10 100 FREQUENCY (MHz)
10 0 0.1
VOUT = 2VP-P -100 1 10 100
VRIPPLE = 100mVP-P 0.1 1 10 100
FREQUENCY (MHz)
FREQUENCY (MHz)
QUIESCENT SUPPLY CURRENT vs. TEMPERATURE
MAX9516 toc07
VOLTAGE GAIN vs. TEMPERATURE
MAX9516 toc08
OUTPUT VOLTAGE vs. INPUT VOLTAGE
MAX9516 toc09
5.0 QUIESCENT SUPPLY CURRENT (mA) 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 -50 -25 0 25 50 75 100
8.20 8.15 VOLTAGE GAIN (V/V) 8.10 8.05 8.00 7.95 7.90 7.85 7.80
2.0 1.5 OUTPUT VOLTAGE (V) 1.0 0.5 0 -0.5 -1.0 -1.5
125
-50
-25
0
25
50
75
100
125
-100 -50 0
50 100 150 200 250 300 350 400 INPUT VOLTAGE (mV)
TEMPERATURE (C)
TEMPERATURE (C)
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
Typical Operating Characteristics (continued)
(VDD = SHDN = 1.8V, GND = 0V, video output has RL = 150 connected to GND, TA = +25C, unless otherwise noted.)
DIFFERENTIAL GAIN AND PHASE
1.6 DIFFERENTIAL GAIN (%) 1.2 0.8 0.4 0 -0.4 1.2 0.8 0.4 0 -0.4 -0.8 -1.2 1 2 3 4 5 6 7 0V 0V
MAX9516 toc10
2T RESPONSE
MAX9516 toc11
12.5T RESPONSE
MAX9516 toc12
IN 50mV/div
IN 50mV/div
DIFFERENTIAL PHASE (deg)
0V OUT 400mV/div 0V OUT 400mV/div
1
2
3
4
5
6
7
100ns/div
400ns/div
NTC-7 VIDEO TEST SIGNAL
MAX9516 toc13
FIELD SQUARE-WAVE (AC-COUPLED)
MAX9516 toc14
IN 100mV/div
IN 100mV/div
0V OUT 800mV/div 0V
0V OUT 800mV/div
0V
10s/div
2ms/div
6
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
Pin Description
PIN 1 2 3 4 5 6 7 8 9 10 NAME VSS C1N CPGND C1P VDD LOAD GND IN SHDN OUT FUNCTION Charge-Pump Negative Power Supply. Bypass with a 1F capacitor to GND. Charge-Pump Flying Capacitor Negative Terminal. Connect a 1F capacitor from C1P to C1N. Charge-Pump Ground Charge-Pump Flying Capacitor Positive Terminal. Connect a 1F capacitor from C1P to C1N. Positive Power Supply. Bypass with a 0.1F capacitor to GND. 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
MAX9516
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.
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).
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-
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.
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
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.
INPUT 500mV/div
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.
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.
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-
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
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).
MAX9516
Table 1. Power Consumption of MAX9516 with Different Video Signals
VIDEO SIGNAL All Black Screen All White Screen 75% Color Bars 50% Flat Field MAX9516 POWER CONSUMPTION (mW) 6.7 18.2 11.6 11.7
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.
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.
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
IMAGE PROCESSOR ASIC
0 TO 1V DAC LPF 150 2V/V
75
Figure 3. Video DAC generates a 1VP-P signal across a 150 resistor connected to ground.
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
Anti-Alias Filter
IMAGE PROCESSOR ASIC
MAX9516
0 TO 0.25V DAC LPF 8V/V
75
37.5
Figure 4. Video DAC Generates a 0.25VP-P Signal Across a 37.5 Resistor Connected to Ground
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.
VDD VIDIN SHDN SHUTDOWN CIRCUIT
MAX9516
LOAD SENSE 56 10 0.1F 18 CLAMP DC LEVEL SHIFT IN LPF VIDEO AMPLIFIER
LOAD
OUT
75
VIDEO DECODER 75
1.8V 0.1F
VDD CHARGE PUMP
LINEAR REGULATOR
GND
CPGND
C1P
C1N VSS C2 1F
C1 1F
Figure 5. MAX9516 Used as an Anti-Alias Filter with Buffer
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
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. 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 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.
MAX9516
Video Signal Routing
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
MAX9516
SHDN
DAC
LUMA (Y) LOAD SENSE
LOAD
IN 0.1F DAC CLAMP CHROMA (C)
LPF VIDEO AMPLIFIER DC LEVEL SHIFT OUT 75
75
1.8V 0.1F
VDD CHARGE PUMP
LINEAR REGULATOR
GND
CPGND
C1P
C1N VSS C2 1F
C1 1F
Figure 6. Luma (Y) and Chroma (C) Signals Added Together to Create Composite Video Signal (Which is AC-Coupled Into the MAX9516)
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
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.
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).
Typical Operating Circuits
VDD
MAX9516
SHDN VIDEO ASIC
LOAD SENSE
LOAD
DAC
IN
LPF VIDEO AMPLIFIER TRANSPARENT CLAMP DC LEVEL SHIFT OUT 75
75
1.8V 0.1F
VDD CHARGE PUMP
LINEAR REGULATOR
GND
CPGND
C1P
C1N VSS C2 1F
C1 1F
Figure 7. DC-Coupled Input
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1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
Typical Operating Circuits (continued)
VDD
MAX9516
MAX9516
SHDN VIDEO ASIC VDD LOAD SENSE LOAD
DAC 0.1F
IN
LPF VIDEO AMPLIFIER CLAMP DC LEVEL SHIFT OUT
1.8V 0.1F
VDD CHARGE PUMP
LINEAR REGULATOR
GND
CPGND
C1P
C1N VSS C2 1F
C1 1F
Figure 8. AC-Coupled Input
Pin Configuration
PROCESS: BiCMOS
TOP VIEW
OUT SHDN IN 10 9 8 GND LOAD 7 6
Chip Information
MAX9516 +
1 VSS 2 3 4 5 VDD
C1N CPGND C1P
DFN
______________________________________________________________________________________
13
1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect MAX9516
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.) 6, 8, 10L UDFN.EPS
A
1 2
D
A
e
b
N
XXXX XXXX XXXX
SOLDER MASK COVERAGE
E
PIN 1 0.10x45
L
PIN 1 INDEX AREA SAMPLE MARKING 7 1 A A
L1
(N/2 -1) x e)
C L
C L
b A A2 A1
L e
EVEN TERMINAL
L e
ODD TERMINAL
PACKAGE OUTLINE, 6, 8, 10L uDFN, 2x2x0.80 mm
-DRAWING NOT TO SCALE-
21-0164
14
______________________________________________________________________________________
1.8V, Ultra-Low-Power, DirectDrive Video Filter Amplifier with Load Detect
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.)
MAX9516
COMMON DIMENSIONS SYMBOL A A1 A2 D E L L1 MIN. 0.70 0.15 0.020 1.95 1.95 0.30 NOM. 0.75 0.20 0.025 2.00 2.00 0.40 0.10 REF. MAX. 0.80 0.25 0.035 2.05 2.05 0.50
PACKAGE VARIATIONS PKG. CODE L622-1 L822-1 L1022-1 N 6 8 10 e 0.65 BSC 0.50 BSC 0.40 BSC b 0.300.05 0.250.05 0.200.03 (N/2 -1) x e 1.30 REF. 1.50 REF. 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.

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