MAX9504BEUT+ [MAXIM]
3V/5V, 6dB Video Amplifiers with High Output-Current Capability;型号: | MAX9504BEUT+ |
厂家: | MAXIM INTEGRATED PRODUCTS |
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19-3750; Rev 0; 7/05
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
General Description
Features
The MAX9504A/MAX9504B 3V/5V, ground-sensing
amplifiers with a fixed gain of 6dB provide high output
current while consuming only 10nA of current in shut-
down mode. The MAX9504A/MAX9504B are ideal for
amplifying DC-coupled video inputs from current digi-
tal-to-analog converters (DACs). The output can drive
two DC-coupled 150Ω back-terminated video loads in
portable media players, security cameras, and automo-
tive video applications. The MAX9504B features an
internal 160mV input offset to prevent output sync tip
clipping when the input signal is close to ground.
♦ DC-Coupled Input/Output
♦ Drives Two DC-Coupled Video Loads
♦ Direct Connection to Ground-Referenced DAC
♦ 42MHz Large-Signal Bandwidth
♦ 47MHz Small-Signal Bandwidth
♦ Internal 160mV Input Offset (MAX9504B)
♦ Single-Supply Operation from +2.7V to +5.5V
♦ 10nA Shutdown Supply Current
♦ Small µDFN (2mm x 2mm) and SOT23 Packages
The MAX9504A/MAX9504B have -3dB large-signal
bandwidth of 42MHz and -3dB small-signal bandwidth
of 47MHz.
Ordering Information
The MAX9504A/MAX9504B operate from a single +2.7V
to +5.5V supply and consume only 5mA of supply cur-
rent. The low-power shutdown mode reduces supply
current to 10nA, making the MAX9504A/MAX9504B ideal
for low-voltage, battery-powered video applications.
PIN-
PKG
OFFSET TOP
(mV)
PART
PACKAGE CODE
MARK
MAX9504AELT-T 6 µDFN-6
L622-1
U65-3
L622-1
U65-3
0
AAJ
ABWC
AAK
MAX9504AEUT+T 6 SOT23-6
0
The MAX9504A/MAX9504B are available in tiny 6-pin
µDFN (2mm x 2mm) and 6-pin SOT23 packages, and
are specified over the -40°C to +85°C extended tem-
perature range.
MAX9504BELT-T
6 µDFN-6
160
160
MAX9504BEUT+
6 SOT23-6
ABWD
Note: All devices specified over the -40°C to +85°C operating
range.
Applications
+Denotes lead-free package.
Car Navigation Systems
Security Cameras
Portable Media Players
Low-Power Video Applications
Y/C-to-CVBS Mixer
Block Diagram
V
CC
Pin Configurations
SHDN
MAX9504A
MAX9504B
TOP VIEW
160mV OFFSET
FB
6
SHDN
5
OUT
4
IN
OUT
FB
MAX9504B
ONLY
2.3kΩ
MAX9504A
MAX9504B
580Ω
1.2kΩ
780Ω
1
2
3
V
CC
GND
IN
µDFN
GND
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
ABSOLUTE MAXIMUM RATINGS
V
to GND..............................................................-0.3V to +6V
Operating Temperature Range ..........................-40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range ............................-65°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
CC
IN, OUT, FB, SHDN to GND .......................-0.3V to (V
OUT Short-Circuit Duration to V
Continuous Power Dissipation (T = +70°C)
+ 0.3V)
CC
or GND ..............Continuous
CC
A
6-Pin SOT23 (derate 8.7mW/°C above +70°C)............695mW
6-Pin µDFN (derate 4.7mW/°C above +70°C) .............377mW
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.
DC ELECTRICAL CHARACTERISTICS
(V
= 3.0V, GND = 0V, V = 0.5V, R = infinity to GND, FB connected to OUT, SHDN = V , T = -40°C to +85°C. Typical values
A
CC
IN L CC A
are at T = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
Guaranteed by PSRR
MIN
TYP
MAX
5.5
9
UNITS
Supply Voltage Range
V
2.7
V
CC
V
V
= 3V
= 5V
5
5
CC
CC
Quiescent Supply Current
Shutdown Supply Current
Input Voltage Range
I
mA
µA
V
CC
9
I
SHDN = 0V
0.01
1
SHDN
MAX9504A
MAX9504B
0.10
0
1.25
1.10
+25
200
20
Inferred from
voltage gain
V
IN
MAX9504A
MAX9504B
-25
120
0
160
5
Input Offset Voltage
V
mV
OS
Input Bias Current
Input Resistance
I
V
= 0V
IN
µA
BIAS
R
0 < V < 1.45V
4
MΩ
IN
IN
V
= 2.7V,
CC
1.9
1.9
2.0
2.0
2
2.1
2.1
0.1V < V < 1.10V
IN
R = 150Ω
L
V
= 3.0V,
CC
(Note 2),
MAX9504A
0.1V < V < 1.25V
IN
V
= 4.5V,
CC
0.1V < V < 1.90V
IN
Voltage Gain
A
V/V
V
V
= 2.7V,
IN
CC
1.9
1.9
2.0
2.0
2
2.1
2.1
0 < V < 0.95V
R = 150Ω
(Note 2),
MAX9504B
L
V
= 3.0V,
CC
0 < V < 1.10V
IN
V
= 4.5V,
CC
0 < V < 1.75V
IN
MAX9504A
MAX9504B
60
50
45
40
80
61
Power-Supply Rejection
Ratio
PSRR
2.7V < V
< 5.5V
dB
CC
Sourcing, R = 20Ω to GND
85
L
Output Current
I
mA
OUT
Sinking, R = 20Ω to V
110
130
L
CC
Output Short-Circuit Current
SHDN Logic-Low Threshold
SHDN Logic-High Threshold
SHDN Input Current
I
OUT shorted to V
or GND
CC
mA
V
SC
V
V
x 0.3
CC
IL
V
V
x 0.7
V
IH
CC
I
SHDN = 0V or V
SHDN = 0V
0.003
4
1.000
µA
IN
CC
Shutdown Output
Impedance
R
OUT
kΩ
(Disabled)
2
_______________________________________________________________________________________
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
AC ELECTRICAL CHARACTERISTICS
(V
= 3.0V, GND = 0V, V = 0.5V, R = 150Ω to GND, FB connected to OUT, SHDN = V , T = +25°C, unless otherwise noted.)
CC
IN
L
CC
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Small-Signal -3dB
Bandwidth
BW
V
V
V
V
= 100mV
47
MHz
SS
LS
OUT
OUT
OUT
OUT
P-P
Large-Signal -3dB
Bandwidth
BW
= 2V
42
10
12
MHz
MHz
MHz
P-P
Small-Signal 0.1dB Gain
Flatness
BW
BW
= 100mV
P-P
0.1dBSS
Large-Signal 0.1dB Gain
Flatness
= 2V
0.1dBLS
P-P
Slew Rate
SR
V
V
= 2V step
= 2V step
165
25
V/µs
ns
OUT
OUT
Settling Time to 1%
t
S
MAX9504A
MAX9504B
75
Power-Supply Rejection
Ratio
PSRR
f = 100kHz
f = 5MHz
NTSC
dB
Ω
49
Output Impedance
Z
2.5
0.1
0.1
0.3
0.3
OUT
V
V
V
V
= 3V
= 5V
= 3V
= 5V
CC
CC
CC
CC
Differential Gain
DG
DP
%
Differential Phase
NTSC
degrees
2T = 250ns, bar time is 18µs, the beginning
2.5% and the ending 2.5% of the bar time
are ignored
2T Pulse-to-Bar K Rating
2T Pulse Response
2T Bar Response
0.2
0.1
0.1
K%
K%
K%
2T = 250ns
2T = 250ns, bar time is 18µs, the beginning
2.5% and the ending 2.5% of the bar time
are ignored
Nonlinearity
5-step staircase
0.1
2
%
ns
dB
ns
ns
Group Delay Distortion
D/dT
SNR
f = 100kHz to 5.5MHz
Peak Signal-to-RMS Noise
Enable Time
V
V
V
= 1V , 100kHz < f < 5MHz
65
300
85
IN
IN
IN
P-P
= 1V, V
= 1V, V
settled to 1% of nominal
t
OUT
OUT
ON
settled to 1% of nominal
Disable Time
t
OFF
Note 1: All devices are 100% production tested at T = +25°C. Specifications over temperature limits are guaranteed by design.
A
Note 2: Voltage gain (A ) is referenced to the input offset voltage; i.e., an input voltage of V would produce an output voltage of
V
IN
V
= A x (V + V ).
OUT
V IN OS
_______________________________________________________________________________________
3
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
Typical Operating Characteristics
(V
= 3.0V, GND = 0V, V = 0.5V, R = 150Ω to GND, FB connected to OUT, SHDN = V , T = +25°C, unless otherwise noted.)
CC
IN
L
CC
A
SMALL-SIGNAL GAIN
vs. FREQUENCY
SMALL-SIGNAL GAIN FLATNESS
vs. FREQUENCY
SMALL-SIGNAL GAIN
vs. FREQUENCY
3
3
0.3
0.2
V
V
= 100mV
P-P
= 3V
OUT
CC
V
V
= 100mV
= 3V
V
V
= 100mV
OUT P-P
OUT
CC
P-P
2
1
2
1
= 5V
CC
0.1
0
0
0
-1
-2
-3
-4
-5
-6
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
-1
-2
-3
-4
-5
-6
0.1
1
10
100
0.1
1
10
100
0.1
1
10
100
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
LARGE-SIGNAL GAIN
vs. FREQUENCY
LARGE-SIGNAL GAIN FLATNESS
vs. FREQUENCY
SMALL-SIGNAL GAIN FLATNESS
vs. FREQUENCY
4
3
0.3
0.2
0.3
0.2
V
V
= 2V
P-P
OUT
V
V
= 2V
P-P
OUT
V
V
= 100mV
P-P
OUT
= 3V
CC
= 3V
CC
= 5V
CC
2
0.1
0.1
1
0
0
0
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
-1
-2
-3
-4
-5
-6
0.1
1
10
100
0.01
0.1
1
10
100
0.1
1
10
100
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
LARGE-SIGNAL GAIN
vs. FREQUENCY
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
LARGE-SIGNAL GAIN FLATNESS
vs. FREQUENCY
4
3
0.3
0.2
10
0
V
V
= 2V
P-P
OUT
V
= 3V
CC
V
V
= 2V
P-P
OUT
= 5V
CC
= 5V
CC
2
-10
-20
-30
-40
-50
-60
-70
-80
-90
0.1
1
0
0
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
-1
-2
-3
-4
-5
-6
MAX9504B
MAX9504A
1
0.1
1
10
100
0.1
1
10
100
0.001
0.01
0.1
10
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
4
_______________________________________________________________________________________
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
Typical Operating Characteristics (continued)
(V
= 3.0V, GND = 0V, V = 0.5V, R = 150Ω to GND, FB connected to OUT, SHDN = V , T = +25°C, unless otherwise noted.)
IN L CC A
CC
MAX9504B INPUT OFFSET VOLTAGE
vs. TEMPERATURE
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
0.19
10
5.50
5.45
5.40
5.35
5.30
5.25
5.20
5.15
5.10
5.05
5.00
4.95
4.90
4.85
4.80
V
= 5V
CC
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
0.18
0.17
0.16
0.15
0.14
V
= 5V
CC
V
= 5V
CC
MAX9504B
V
= 3V
CC
V
= 3V
CC
MAX9504A
1
-40
-15
10
35
60
85
0.001
0.01
0.1
10
-40
-15
10
35
60
85
TEMPERATURE (°C)
FREQUENCY (MHz)
TEMPERATURE (°C)
VOLTAGE GAIN
vs. TEMPERATURE
LARGE-SIGNAL STEP RESPONSE
MAX9504 toc14
2.10
2.05
2.00
1.95
1.90
V
= 3V and 5V
CC
V
IN
500mV/div
V
OUT
1V/div
-40
-15
10
35
60
85
10ns/div
TEMPERATURE (°C)
DIFFERENTIAL GAIN AND PHASE
0.2
SMALL-SIGNAL STEP RESPONSE
MAX9504 toc15
0.1
0
-0.1
-0.2
0.4
V
IN
25mV/div
1
2
3
4
5
6
0.2
0
V
OUT
-0.2
-0.4
50mV/div
1
2
3
4
5
6
10ns/div
_______________________________________________________________________________________
5
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
Typical Operating Characteristics (continued)
(V
= 3.0V, GND = 0V, V = 0.5V, R = 150Ω to GND, FB connected to OUT, SHDN = V , T = +25°C, unless otherwise noted.)
IN L CC A
CC
OUT RESPONSE TO NTC-7
TEST SIGNAL (MAX9504B)
OUT RESPONSE TO NTC-7
TEST SIGNAL (MAX9504B)
MAX9504 toc18
MAX9504 toc17
V
IN
V
IN
500mV/div
500mV/div
GND
GND
GND
GND
V
OUT
V
OUT
1V/div
1V/div
V = 5V
CC
V
= 3V
CC
10µs/div
10µs/div
OUT RESPONSE TO A FIELD
SQUARE WAVE (MAX9504B)
OUT RESPONSE TO A FIELD
SQUARE WAVE (MAX9504B)
MAX9504 toc19
MAX9504 toc20
V
= 3V
V
= 5V
CC
CC
V
IN
V
IN
500mV/div
500mV/div
GND
GND
GND
GND
V
OUT
V
OUT
1V/div
1V/div
2ms/div
2ms/div
Pin Description
PIN
NAME
FUNCTION
SOT23
µDFN
1
2
3
4
5
6
4
2
3
1
5
6
OUT
GND
IN
Video Output
Ground
Video Input
V
Power-Supply Input. Bypass V
with a 0.1µF capacitor to ground as close as possible to V
.
CC
CC
CC
SHDN
Shutdown Input. Pull SHDN low to place the device in low-power shutdown mode.
FB
Feedback. Connect FB to OUT.
6
_______________________________________________________________________________________
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
Typical Application Circuit
V
2.7V TO 5.5V
CC
0.1µF
V
CC
3-POLE RECONSTRUCTION LPF
C3
SHDN
MAX9504A
MAX9504B
Z = 75Ω
0
75Ω
75Ω
160mV OFFSET
L1
VIDEO
CURRENT
DAC
IN
OUT
FB
75Ω
75Ω
MAX9504B
ONLY
C2
C1
R1
R2
Z = 75Ω
0
GND
Input Offset (MAX9504B)
Detailed Description
The MAX9504A/MAX9504B amplify DC-coupled video
signals with a gain of +2V/V (+6dB). The MAX9504B
The MAX9504A/MAX9504B 3V/5V, 6dB video amplifiers
with low-power shutdown mode accept DC-coupled
inputs and drive up to two DC-coupled, 150Ω back-ter-
minated video loads. The MAX9504B provides an inter-
nal input offset voltage of 160mV, which allows
DC-coupled input signals down to ground without clip-
ping the output sync tip.
features a 160mV input offset voltage (V ) that allows
OS
a video signal input range to ground without clipping
the output sync tip. The MAX9504B output voltage is
the sum of the input voltage and the input offset voltage
gained up by a factor of 2.
V
= 2 x (V + V
)
OUT
IN
OS
The MAX9504A/MAX9504B operate from a single +2.7V
to +5.5V supply and consume only 5mA of supply cur-
rent. The low-power shutdown mode reduces supply cur-
rent to less than 1µA, making the MAX9504A/MAX9504B
ideal for low-voltage, battery-powered video applications.
For example, if V = 1V and V = 0.16V then:
IN
OS
V
= 2 x (1V + 0.16V) = 2.32V
OUT
Shutdown Mode
The MAX9504A/MAX9504B feature a low-power shut-
down mode (I < 1µA) for battery-powered/
portable applications. Driving SHDN high enables the
output. Driving SHDN low disables the output and
places the MAX9504A/MAX9504B into a low-power
shutdown mode. In shutdown, the output resistance is
4kΩ (typ) due to the combination of feedback resistors
from OUT to ground with FB connected to OUT.
Output Current Capability
As shown in the Typical Application Circuit, the
MAX9504A/MAX9504B can drive up to two 150Ω loads
to ground at the same time because the outputs can
source guaranteed 45mA (min) current. Two 150Ω loads
to ground is the same as a single 75Ω load to ground.
SHDN
Since the MAX9504A/MAX9504B can also sink guaran-
teed 40mA (min) current, they can also drive two, AC-cou-
pled 150Ω loads. When V
> 3V, the output can swing
CC
2.4V . When V > 4.5V, the output can swing 2.8V .
P-P
CC
P-P
_______________________________________________________________________________________
7
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
320mV. As a result, the MAX9504B output stage always
operates in the linear mode. Even if the input signal is
at ground, the MAX9504B output is at 320mV.
Applications Information
Using the MAX9504A/MAX9504B
with Video Current DACs
At the output of a video current DAC, the blank level of
the chroma signal is usually between 500mV to 650mV.
The voltage swing above and below the blank level is
approximately 350mV (see Figure 1). If the blank level
is 550mV, then the lowest voltage for the chroma signal
is 200mV. For the case of chroma signals, no input
level shift is needed because 200mV gained up by two
is 400mV, which is well within the linear output range of
the MAX9504A or MAX9504B. Since the MAX9504A
does not have an input level shift, the MAX9504A
should be used with chroma signals. In summary, use
the MAX9504B with composite video and luma signals
from a DAC, and use the MAX9504A with chroma sig-
nals from a DAC.
Video current DACs source current into a resistor con-
nected to ground. The output voltage range for com-
posite video and luma (Y) is usually from ground up to
1V (see Figure 1). Notice that the sync tip is quite close
to ground. Standard single-supply amplifiers with rail-
to-rail outputs have difficulty amplifying input signals at
or near ground because their output stages enter a
nonlinear mode of operation when the output is pulled
close to ground.
The MAX9504B level shifts the input signal up by
160mV so that the output has a positive DC offset of
MAX9504 fig01
Using the MAX9504A/MAX9504B with a
Video Reconstruction Filter
In most video applications, the video signal generated
from the DAC requires a reconstruction filter to smooth
out the steps and reduce the spikes. The MAX9504 has
a high-impedance, DC-coupled input that can be con-
nected directly to the reconstruction filter.
LUMA
500mV/div
GND
For standard-definition video, the video passband is
approximately 6MHz, and the DAC sampling clock is
27MHz. Normally, a 9MHz lowpass filter can be used
for the reconstruction filter. This section demonstrates
the methods to build simple 2nd- and 3rd-order pas-
sive Butterworth lowpass filters with 9MHz cutoff fre-
quency. See Figures 2 and 3.
CHROMA
500mV/div
GND
10µs/div
Figure 1. Oscilloscope Trace of Luma and Chroma Signals
from Video Current DAC
V
CC
C7
0.1µF
2-POLE RECONSTRUCTION LPF
L1
R3
75Ω
V
CC
V
OUT
3.9µH
VIDEO
CURRENT
DAC
IN
OUT
FB
C1
150pF
MAX9504
GND
R1
150Ω
R2
150Ω
SHDN
V
CC
Figure 2. 2nd-Order Butterworth LPF with MAX9504
_______________________________________________________________________________________
8
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
3-POLE RECONSTRUCTION LPF
V
CC
C3
6.8pF
C7
0.1µF
L1
4.7µH
R3
75Ω
V
CC
V
OUT
VIDEO
CURRENT
DAC
IN
OUT
FB
C1
120pF
C2
120pF
R1
150Ω
R2
150Ω
MAX9504
GND
SHDN
V
CC
Figure 3. 3rd-Order Butterworth LPF with MAX9504
2nd-Order Butterworth Lowpass Filter Realization
Table 2. Bench Measurement Values
(2nd-Order LPF)
Table 1 shows the normalized 2nd-order Butterworth
LPF component values at 1 rad/s with a source/load
impedance of 1Ω.
3dB
R1 = R2
C1
L1
ATTENUATION AT
27MHz (dB)
With the following equations, the L and C can be calcu-
lated for the cutoff frequency (f ) at 9MHz. Table 2
C
FREQUENCY
(MHz)
(Ω)
(pF)
(µH)
shows the appropriate L and C values for different
source/load impedances, the bench measurement val-
ues for the -3dB frequency and the attenuation at
27MHz. There is approximately 20dB attenuation at
27MHz, which decreases the spikes at the sampling
frequency.
75
330
150
120
82
1.8
3.9
4.7
8.2
8.7
9.0
9.3
8.7
20
20
22
20
150
200
300
Cn1
C1 =
FREQUENCY RESPONSE
2πfcR1
0
-10
-20
-30
-40
-50
-60
Ln1R1
2πfc
L1 =
Figure 4 shows the frequency response for R1 = R2 =
150Ω. At 6MHz, the attenuation is about 1.4dB. The
attenuation at 27MHz is about 20dB. Figure 5 shows
the multiburst response for R1 = R2 = 150Ω.
Table 1. 2nd-Order Butterworth Lowpass
Filter Normalized Values
0.1
1
10
100
Rn1 = Rn2 (Ω)
Cn1 (F)
Ln1 (H)
FREQUENCY (MHz)
1
1.414
1.414
Figure 4. Frequency Response for 2nd-Order Lowpass Filter
_______________________________________________________________________________________
9
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
FREQUENCY RESPONSE
0
-10
V
IN
500mV/div
-20
-30
-40
-50
-60
V
OUT
1V/div
0.1
1
10
100
10µs/div
FREQUENCY (MHz)
Figure 5. Multiburst Response
Figure 6. Frequency Response for 3rd-Order Lowpass Filter
3rd-Order Butterworth Lowpass Filter Realization
If a flatter passband and more stopband attenuation
are desired, a 3rd-order lowpass filter can be used.
The design procedures are similar to the 2nd-order
Butterworth lowpass filter.
Y/C-to-Composite Mixer and Driver Circuit
The Y/C-to-composite mixer and driver use two low-
pass filters, the MAX9504A and the MAX9504B. In
Figure 7, the top video DAC generates a luma signal,
which is filtered through the passive RLC network and
then amplified by the MAX9504B. The bottom video
DAC generates a chroma signal, which is filtered and
then amplified by the MAX9504A.
Table 3 shows the normalized 3rd-order Butterworth
lowpass filter with the cutoff frequency at 1 rad/s and
the stopband frequency at 3 rad/s. Table 4 shows the
appropriate L and C values for different source/load
impedances, the bench measurement values for the -3dB
frequency and the attenuation at 27MHz. The attenua-
tion is over 40dB at 27MHz. At 6MHz, the attenuation is
approximately 0.6dB for R1 = R2 = 150Ω (Figure 6).
LUMA OUT is directly connected to the output of the
MAX9504B through a 75Ω back-termination resistor;
likewise, CHROMA OUT to the output of the MAX9504A.
CVBS OUT (the composite video with blanking and
sync output) is created by AC-coupling the chroma sig-
nal to the luma signal through the 470pF capacitor,
which looks like an AC short at the color subcarrier fre-
quency of 3.58MHz for NTSC or 4.43MHz for PAL.
Table 3. 3rd-Order Butterworth Lowpass
Filter Normalized Values
This circuit relies upon the feature that the MAX9504A/
MAX9504B can drive two loads at the same time.
Rn1 = Rn2
Cn1 (F)
Cn2 (F)
Cn3 (F)
Ln1 (H)
(Ω)
1
0.923
0.923
0.06
1.846
Table 4. Bench Measurement Values—3rd Order LPF
R1 = R2 (Ω)
C1 (pF)
220
C2 (pF)
220
C3 (pF)
15.0
6.8
L (µH)
2.2
3dB FREQUENCY (MHz) ATTENUATION AT 27MHz (dB)
75
9.3
8.9
9.0
43
50
45
150
300
120
120
4.7
56
56
3.3
10.0
10 ______________________________________________________________________________________
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
3-POLE RECONSTRUCTION LPF
V
CC
6.8pF
0.1µF
LUMA
V
CC
75Ω
4.7µH
VIDEO
CURRENT
DAC
LUMA OUT
IN
OUT
MAX9504B
120pF
120pF
150Ω
150Ω
FB
SHDN
GND
75Ω
75Ω
CHROMA OUT
CVBS OUT
3-POLE RECONSTRUCTION LPF
6.8pF
0.1µF
CHROMA
V
CC
470pF
75Ω
4.7µH
VIDEO
CURRENT
DAC
IN
OUT
FB
MAX9504A
120pF
120pF
150Ω
150Ω
SHDN
GND
V
CC
Figure 7. Y/C-to-Composite Mixer and Driver Circuit
______________________________________________________________________________________ 11
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
microstrip and stripline techniques to obtain full band-
AC Output Coupling and Sag Correction
width. To ensure that the PC board does not degrade
the device’s performance, design it for a frequency
greater than 1GHz. Pay careful attention to inputs and
outputs to avoid large parasitic capacitance. Whether
or not you use a constant-impedance board, observe
the following design guidelines:
The MAX9504 can use the sag configuration if the out-
put requires AC-coupling and V
≥ 4.5V. Sag correc-
CC
tion refers to the low-frequency compensation for the
highpass filter formed by the 150Ω load and the output
capacitor. In video applications, the cutoff frequency
must be less than 5Hz in order to pass the vertical sync
interval and avoid field time distortion (field tilt). In the
simplest configuration, a very large coupling capacitor
(> 220µF typically) is used to achieve the 5Hz cutoff
frequency. In the sag configuration, two smaller capaci-
tors are used to replace the very large coupling capaci-
• Do not use wire-wrap boards; they are too inductive.
• Do not use IC sockets; they increase parasitic capaci-
tance and inductance.
• Use surface-mount instead of through-hole compo-
nents for better, high-frequency performance.
tor (see Figure 8). For V
capacitors.
≥ 4.5V, C5 and C6 are 22µF
CC
• Use a PC board with at least two layers; it should be
as free from voids as possible.
Layout and Power-Supply Bypassing
The MAX9504A/MAX9504B operate from a single 2.7V
to 5.5V supply. Bypass the supply with a 0.1µF capaci-
• Keep signal lines as short and as straight as possible.
Do not make 90° turns; round all corners.
tor as close to V
possible. Maxim recommends using
CC
3-POLE RECONSTRUCTION LPF
V
CC
C3
6.8pF
C7
0.1µF
C5
22µF
L1
4.7µH
R3
75Ω
V
CC
V
OUT
VIDEO
CURRENT
DAC
IN
OUT
FB
C1
120pF
R1
150Ω
C2
120pF
R2
150Ω
C6
22µF
MAX9504
GND
SHDN
V
CC
Figure 8. SAG Correction Configuration
12 ______________________________________________________________________________________
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
Typical Operating Circuit
V
CC
2.7V TO 5.5V
0.1µF
V
CC
3-POLE RECONSTRUCTION LPF
C3
6.8pF
SHDN
MAX9504A
MAX9504B
Z = 75Ω
0
75Ω
75Ω
L1
4.7µH
160mV OFFSET
VIDEO
CURRENT
DAC
IN
OUT
FB
75Ω
75Ω
C2
120pF
C1
120pF
R1
150Ω
R2
150Ω
MAX9504B
ONLY
Z = 75Ω
0
2.3kΩ
580Ω
1.2kΩ
780Ω
GND
Pin Configurations (continued)
Chip Information
PROCESS: BiCMOS
TOP VIEW
+
OUT
GND
IN
1
2
3
6
5
4
FB
MAX9504A
MAX9504B
SHDN
V
CC
SOT23-6
______________________________________________________________________________________ 13
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
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.)
14 ______________________________________________________________________________________
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
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.)
A
b
D
e
N
XXXX
XXXX
XXXX
SOLDER
MASK
COVERAGE
E
PIN 1
0.10x45∞
L
L1
1
SAMPLE
MARKING
PIN 1
INDEX AREA
A
A
7
(N/2 -1) x e)
C
L
C
L
b
L
L
A
e
e
A2
EVEN TERMINAL
ODD TERMINAL
A1
PACKAGE OUTLINE,
6, 8, 10L uDFN, 2x2x0.80 mm
1
-DRAWING NOT TO SCALE-
21-0164
A
2
______________________________________________________________________________________ 15
3V/5V, 6dB Video Amplifiers with
High Output-Current Capability
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.)
COMMON DIMENSIONS
SYMBOL
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
MAX.
0.80
0.25
0.035
2.05
2.05
0.50
A
A1
A2
D
-
E
L
L1
0.10 REF.
PACKAGE VARIATIONS
PKG. CODE
L622-1
N
6
e
b
(N/2 -1) x e
0.65 BSC
0.50 BSC
0.40 BSC
0.30±0.05 1.30 REF.
0.25±0.05 1.50 REF.
0.20±0.03 1.60 REF.
L822-1
8
L1022-1
10
PACKAGE OUTLINE,
6, 8, 10L uDFN, 2x2x0.80 mm
2
21-0164
A
-DRAWING NOT TO SCALE-
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.
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
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