MAX9516ALB+T

EVALUATION KIT AVAILABLE
MAX9516
General Description
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 DirectDrive™
technology. Combining DirectDrive® with the external positive 1.8V supply, the MAX9516 is able to drive a 2VP-P
video signal into a 150Ω 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 31μW.
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
19-0995; Rev 1; 5/14
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Features
●● 1.8V or 2.5V Single-Supply Operation
●● Low Power Consumption (6mW Quiescent,
12mW Average)
●● Video Load Detect
●● Reconstruction Filter with 5.5MHz Passband
●● DirectDrive Sets Video Output Black Level Near
Ground
●● DC-Coupled Input/Output
●● Transparent Input Sync-Tip Clamp
Ordering Information
PART
PIN-PACKAGE
MAX9516ALB+T
PKG CODE
TOP
MARK
L1022+1
AAN
10 FDFN-10
Note: This device operates over the -40°C to +125°C operating
temperature range.
+Denotes lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Block Diagram
MAX9516
IN
250mVP-P
VIDEO
SHDN
LPF
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.
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
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 = +70°C)
10-Pin μDFN (derate 5mW/°C above +70°C)..............403mW
Operating Temperature Range.......................... -40°C to +125°C
Junction Temperature.......................................................+150°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
(VDD = SHDN = +1.8V, GND = 0V, OUT has RL = 150Ω connected to GND, C1 = C2 = 1μF, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at VDD = 1.8V, TA = +25°C.) (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
-85
MAX
UNITS
2.625
V
5.3
mA
µA
0.01
10
µA
200
Ω
+9
+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
IN = 130mV
2
10mV ≤ IN ≤ 250mV
3.5
295
mV
µA
kΩ
AC-COUPLED INPUT
Sync-Tip Clamp Level
VCLP
CIN = 0.1µF
-8
0
1.7V ≤ VDD ≤ 2.625V
+11
252.5
mV
Input-Voltage Swing
Guaranteed by
output-voltage swing
Sync Crush
Percentage reduction in sync pulse at output,
RSOURCE = 37.5Ω, CIN = 0.1µF
Input Clamping Current
IN = 130mV
2
Line Time Distortion
CIN = 0.1µF
0.2
%
25
Ω
Minimum Input Source
Resistance
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2.375V ≤ VDD ≤ 2.625V
325
1.3
mVP-P
%
3.5
µA
Maxim Integrated │ 2
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Electrical Characteristics (continued)
(VDD = SHDN = +1.8V, GND = 0V, OUT has RL = 150Ω connected to GND, C1 = C2 = 1μF, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at VDD = 1.8V, TA = +25°C.) (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
MΩ
OUT = 0V, -5mA ≤ ILOAD ≤ +5mA
0.02
Ω
Shutdown Output Resistance
0V ≤ OUT ≤ VDD, SHDN = GND
10.0
MΩ
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 P VDD ≤ 2.625V, measured between 75Ω
load resistors
Power-Supply Rejection Ratio
Shutdown Input Resistance
Output Resistance
ROUT
Output Short-Circuit Current
1
Sourcing
81
Sinking
45
±1dB passband flatness
OUT = 2VP-P,
f = 5.5MHz
reference frequency
f = 8.5MHz
is 100kHz
f = 27MHz
7.5
-48.7
f = 3.58MHz
1.05
f = 4.43MHz
1.1
VP-P
µA
mA
AC CHARACTERISTICS
Standard-Definition
Reconstruction Filter
Differential Gain
DG
Differential Phase
DP
MHz
-0.2
-3.0
f = 3.58MHz
0.4
f = 4.43MHz
0.45
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 18µs, 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 18µs, the beginning
2.5% and the ending 2.5% of the bar time is
ignored
0.1
K%
Power-Supply Rejection Ratio
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PSRR
Maxim Integrated │ 3
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Electrical Characteristics (continued)
(VDD = SHDN = +1.8V, GND = 0V, OUT has RL = 150Ω connected to GND, C1 = C2 = 1μF, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at VDD = 1.8V, TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Nonlinearity
5-step staircase
0.2
%
Output Impedance
f = 5MHz, IN = 80mV
7.5
Ω
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
µA
LOGIC SIGNALS
Logic-Low Threshold
Logic-High Threshold
VIL
SHDN, VDD = 1.7V to 2.625V
VIH
SHDN, VDD = 1.7V to 2.625V
Logic Input Current
IIL, IIH
Output High Voltage
VOH
LOAD, IOH = 3mA
Output Low Voltage
VOL
LOAD, IOL = 3mA
1.4
V
SHDN
VDD - 0.4
V
0.4
V
Note 1: All devices are 100% production tested at TA = +25°C. 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 = 150Ω connected to GND, TA = +25°C, unless otherwise noted.)
0
0.5
LARGE-SIGNAL GAIN
vs. FREQUENCY
20
MAX9516 toc02
1.0
MAX9516 toc01
20
SMALL-SIGNAL GAIN FLATNESS
vs. FREQUENCY
MAX9516 toc03
SMALL-SIGNAL GAIN
vs. FREQUENCY
0
0
-40
-60
-20
-0.5
GAIN (dB)
GAIN (dB)
GAIN (dB)
-20
-1.0
-1.5
-40
-60
-2.0
-80
-100
0.1
1
10
FREQUENCY (MHz)
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-80
-2.5
VOUT = 100mVP-P
100
-3.0
VOUT = 100mVP-P
0.1
1
10
FREQUENCY (MHz)
100
-100
VOUT = 2VP-P
0.1
1
10
100
FREQUENCY (MHz)
Maxim Integrated │ 4
MAX9516
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 = 150Ω connected to GND, TA = +25°C, unless otherwise noted.)
0.5
100
90
-1.5
50
40
1
0.1
10
0
100
VOUT = 2VP-P
1
0.1
10
100
VRIPPLE = 100mVP-P
0.1
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
2.0
8.10
8.05
8.00
7.95
7.90
-25
0
25
50
75
TEMPERATURE (°C)
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100
125
7.80
1.0
0.5
0
-0.5
-1.0
7.85
1.5
1.5
OUTPUT VOLTAGE (V)
VOLTAGE GAIN (V/V)
4.0
2.0
100
MAX9516 toc09
8.20
MAX9516 toc08
4.5
-50
-100
FREQUENCY (MHz)
MAX9516 toc07
5.0
-80
10
VOUT = 2VP-P
-40
-60
20
-2.5
QUIESCENT SUPPLY CURRENT (mA)
60
30
-2.0
1.0
-20
70
PSSR (dB)
-1.0
-3.0
0
80
-0.5
DELAY (ns)
GAIN (dB)
0
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
20
MAX9516 toc05
110
MAX9516 toc04
1.0
GROUP DELAY
vs. FREQUENCY
MAX9516 toc06
LARGE-SIGNAL GAIN FLATNESS
vs. FREQUENCY
-50
-25
0
25
50
75
TEMPERATURE (°C)
100
125
-1.5
-100 -50 0
50 100 150 200 250 300 350 400
INPUT VOLTAGE (mV)
Maxim Integrated │ 5
MAX9516
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 = 150Ω connected to GND, TA = +25°C, unless otherwise noted.)
DIFFERENTIAL GAIN AND PHASE
DIFFERENTIAL
GAIN (%)
12.5T RESPONSE
MAX9516 toc11
MAX9516 toc12
1.2
IN
50mV/div
0.8
0.4
IN
50mV/div
0
-0.4
DIFFERENTIAL
PHASE (deg)
2T RESPONSE
MAX9516 toc10
1.6
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
0V
OUT
800mV/div
0V
0V
OUT
800mV/div
0V
10µs/div
www.maximintegrated.com
IN
100mV/div
2ms/div
Maxim Integrated │ 6
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Pin Description
PIN
NAME
FUNCTION
1
VSS
Charge-Pump Negative Power Supply. Bypass with a 1µF capacitor to GND.
2
C1N
Charge-Pump Flying Capacitor Negative Terminal. Connect a 1µF capacitor from C1P to C1N.
3
CPGND
4
C1P
Charge-Pump Flying Capacitor Positive Terminal. Connect a 1µF capacitor from C1P to C1N.
5
VDD
Positive Power Supply. Bypass with a 0.1µF capacitor to GND.
6
LOAD
Load-Detect Output. LOAD goes high when an output video load is detected.
7
GND
Ground
8
IN
9
SHDN
10
OUT
Charge-Pump 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.
output connection in an attempt to eliminate 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 220μF to 3000μF. For spac
constrained 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.
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 150Ω load.
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
Video Amplifier
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
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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.
Maxim Integrated │ 7
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.
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 150Ω). 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.
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 7.5kΩ 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 31μW.
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OUTPUT
500mV/div
2ms/div
Figure 1. AC-Coupled Output
INPUT
500mV/div
0V
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 synctip 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-coupled input,
Maxim Integrated │ 8
MAX9516
the sync-tip clamp automatically clamps the input signal
to ground, preventing it from going lower. A small current
of 2μA 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 additionalvariation 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 synctip 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).
Short-Circuit Protection
In Figure 7, the MAX9516 includes a 75Ω 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 150Ω load to ground with a 50% flat field. Under
such conditions, the average power consumption for the
www.maximintegrated.com
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
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
MAX9516 is 12mW. Table 1 shows the power consumption with different video signals. The supply voltage is
1.8V. OUT drives a 150Ω 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 150Ω 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 150Ω resistor to a
37.5Ω resistor, as shown in Figure 4. The 37.5Ω resistor
is one-quarter of the 150Ω resistor, resulting in a video
signal that is one-quarter the amplitude.
IMAGE
PROCESSOR
ASIC
DAC
75Ω
0 TO 1V
LPF
2V/V
150Ω
Figure 3. Video DAC generates a 1VP-P signal across a 150Ω
resistor connected to ground.
Maxim Integrated │ 9
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
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 74Ω (56Ω and 18Ω 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 10Ω series resistor increases
the equivalent source resistance to about 25Ω, which is
the minimum necessary for a video source to drive the
internal sync-tip clamp.
IMAGE
PROCESSOR
ASIC
MAX9516
75Ω
0 TO 0.25V
DAC
LPF
8V/V
37.5Ω
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.
Figure 4. Video DAC Generates a 0.25VP-P Signal Across a
37.5Ω Resistor Connected to Ground
VDD
MAX9516
SHUTDOWN
CIRCUIT
SHDN
VIDIN
LOAD SENSE
LOAD
56Ω
10Ω
IN
LPF
VIDEO
AMPLIFIER
0.1µF
18Ω
CLAMP
1.8V
DC
LEVEL SHIFT
OUT
75Ω
VIDEO
DECODER
75Ω
LINEAR
REGULATOR
VDD
CHARGE PUMP
0.1µF
GND
CPGND
C1P
C1
1µF
C1N VSS
C2
1µF
Figure 5. MAX9516 Used as an Anti-Alias Filter with Buffer
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Maxim Integrated │ 10
MAX9516
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.
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
DAC
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
SHDN
LUMA (Y)
LOAD SENSE
IN
LPF
0.1µF
DAC
VIDEO
AMPLIFIER
CLAMP
CHROMA (C)
1.8V
LOAD
DC
LEVEL SHIFT
OUT
75Ω
75Ω
LINEAR
REGULATOR
VDD
CHARGE PUMP
0.1µF
GND
CPGND
C1P
C1
1µF
C1N VSS
C2
1µF
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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Maxim Integrated │ 11
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Power-Supply Bypassing
and Ground Management
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).
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 0.1μF capacitor to
GND, placed as close to the device as possible. Bypass
VSS with a 1μF capacitor to GND as close to the device
as possible. The total system bypass capacitance on
VDD should be at least 10μF 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
DC
CLAMP
LEVEL SHIFT
1.8V
LOAD
OUT
75Ω
75Ω
LINEAR
REGULATOR
VDD
CHARGE PUMP
0.1µF
GND
CPGND
C1P
C1
1µF
C1N VSS
C2
1µF
Figure 7. DC-Coupled Input
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Maxim Integrated │ 12
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Typical Operating Circuits (continued)
VDD
MAX9516
SHDN
VDD
VIDEO
ASIC
LOAD SENSE
IN
DAC
LPF
0.1µF
OUT
VIDEO
AMPLIFIER
CLAMP
DC
LEVEL SHIFT
LINEAR
REGULATOR
VDD
1.8V
LOAD
CHARGE PUMP
0.1µF
GND
CPGND
C1P
C1
1µF
C1N VSS
C2
1µF
Figure 8. AC-Coupled Input
Chip Information
Pin Configuration
TOP VIEW
PROCESS: BiCMOS
OUT SHDN IN
10
9
8
GND LOAD
7
6
MAX9516
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
+
1
2
3
4
5
VSS C1N CPGND C1P VDD
µDFN
www.maximintegrated.com
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE NO.
LAND
PATTERN
NO.
10 µDFN
L1022+1
21-0164
90-0006
Maxim Integrated │ 13
MAX9516
1.8V, Ultra-Low-Power, DirectDrive
Video Filter Amplifier with Load Detect
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
9/07
Initial release
—
1
5/14
Removed automotive reference from Applications section
1
DESCRIPTION
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2014 Maxim Integrated Products, Inc. │ 14