19-4031; Rev 0; 2/08
Video Y/C Summer with
Driver and Chroma Mute
General Description
The MAX11503 is a low-power video amplifier with a
Y/C summer and chroma mute. The device accepts an
S-video or Y/C input and sums the luma (Y) and chroma
(C) signals into a composite CVBS signal which can be
connected directly to a TV monitor. The MAX11503 drives
two terminated 75Ω video coax cables.
The MAX11503 features include chroma mute, power
save, and SAG correction. Chroma mute disables the
chroma buffer. If the device is used to combine Y and
C signals in a camera application, the chroma mute
may be used in low-light situations. This removes all
chroma including burst which causes a downstream
composite video decoder to interpret the video signal
as luminance only, thus improving image quality. SAG
correction allows small output capacitors to be used in
AC-coupled output applications.
The MAX11503 operates from a single 2.7V to 5.25V
supply, is specified over the extended -40°C to +85°C
temperature range, and is available in a small 8-pin
µMAX
®
package.
♦
Low Operating Voltage
♦
Internal Y/C Summer with Chroma Mute Capability
♦
AC- or DC-Coupled Inputs
♦
AC- or DC-Coupled Outputs
♦
Output Buffer Drives Two Terminated 75Ω Video
Coax Cables
♦
SAG Correction Allows for Small Output
Capacitors
♦
Low-Power Standby, 0.5µA at 3.0V
Features
MAX11503
Ordering Information
PART
MAX11503EUA+
TEMP RANGE
-40°C to +85°C
PIN-
PACKAGE
8 µMAX-EP*
PKG
CODE
U8E+2
Applications
Security Cameras
CCD Cameras
Digital Cameras
Portable Media Players
+Denotes
lead-free package.
*EP
= Exposed pad.
Pin Configuration appears at end of data sheet.
Functional Diagram
V
CC
0.1µF
1µF
SYSTEM
ON A
CHIP
(SOC) Y
PSAVE
0.1µF*
YIN
TRANSPARENT
CLAMP
BUFFER
Σ
+6dB
OUT
68µF*
75Ω
MAX11503
C
CIN
CMUTE
AC-COUPLING
AND BIAS
BUFFER
SAG
33µF*
GND
75Ω
*REMOVE AND SHORT FOR DC-COUPLED OPERATION
µMAX is a registered trademark of Maxim Integrated Products, Inc.
________________________________________________________________
Maxim Integrated Products
1
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.
Video Y/C Summer with
Driver and Chroma Mute
MAX11503
ABSOLUTE MAXIMUM RATINGS
Any Pin to GND .....................................................-0.3V to +5.5V
Maximum Current into Any Pin Except V
CC
and GND ....±-50mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX-EP
Single-Layer Board (derate 10.3mW/°C
above +70°C)...........................................................824mW
Multilayer Board (derate 12.9 mW/°C
above +70°C).........................................................1030mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead temperature (soldering, 10s) ..................................+300°C
Junction Temperature ......................................................+150°C
ESD Protection (Human Body Model)..................................±2kV
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
(V
CC
= 3.0V, V
PSAVE
= V
CC
, V
CMUTE
= 0V, R
L
= 150Ω, AC-coupled, T
A
= +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
Input AC-coupled to ground, no output load,
V
CC
= 2.7V
Operating Current
I
CC
Input AC-coupled to ground, no output load,
V
CC
= 3.0V
Input AC-coupled to ground, no output load,
V
CC
= 5.25V
Supply Voltage Range
Operating Temperature
Range
Operating Current
(Power-Save Mode)
V
CC
T
PSAVE
= 0, V
CC
= 2.7V
I
CCS
PSAVE
= 0, V
CC
= 3.0V
PSAVE
= 0, V
CC
= 5.25V
V
CC
= 2.7V
V
OM
V
CC
= 3.0V
V
CC
= 5.25V
V
CC
= 2.7V
Voltage Gain
A
V
V
CC
= 3.0V
V
CC
= 5.25V
Frequency
Characteristic
YIN = 100kHz to 5.5MHz, V
CC
= 2.7V
∆A
V
YIN = 100kHz to 5.5MHz, V
CC
= 3.0V
YIN = 100kHz to 5.5MHz, V
CC
= 5.25V
V
CC
= 2.7V
Differential Gain
dG
V
CC
= 3.0V
V
CC
= 5.25V
V
CC
= 2.7V
Differential Phase
dφ
V
CC
= 3.0V
V
CC
= 5.25V
-1
2.2
2.4
6
6
6
0
0
0
0.5
0.1
0.12
0.3
0.3
0.3
Degrees
%
+1
dB
dB
2.70
-40
0.5
0.5
0.5
2.0
V
P-P
µA
MIN
TYP
8
8
8
5.25
+85
V
o
MAX
UNITS
14.0
mA
C
Maximum Output
Voltage
2
_______________________________________________________________________________________
Video Y/C Summer with
Driver and Chroma Mute
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.0V, V
PSAVE
= V
CC
, V
CMUTE
= 0V, R
L
= 150Ω, AC-coupled, T
A
= +25°C, unless otherwise noted.)
PARAMETER
Signal-to-Noise Ratio
SYMBOL
SNR
CONDITIONS
Weighted, V
CC
= 2.7V
Weighted, V
CC
= 3.0V
Weighted, V
CC
= 5.25V
Second Harmonic
Distortion
Chroma Input
Resistance
Logic-Input Voltage
Low
Logic-Input Voltage
High
2HD
3.58MHz, V
CC
= 2.7V
3.58MHz, V
CC
= 3.0V
3.58MHz, V
CC
= 5.25V
R
CIN
V
IL
V
IH
0.7 x
V
CC
MIN
TYP
-65
-62
-65
-48
-48
-48
800
0.6
kΩ
V
V
dB
dB
MAX
UNITS
MAX11503
Typical Operating Characteristics
(V
CC
= 3.0V, V
PSAVE
= V
CC
, V
CMUTE
= 0V, R
L
= 150Ω, AC-coupled, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX11503 toc01
VIDEO OUTPUT WAVEFORM
(CMUTE = 0)
MAX11503 toc02
VIDEO OUTPUT WAVEFORM
(CMUTE = 1)
MAX11503 toc03
10
SUPPLY CURRENT (mA)
9
YIN
500mV/div
CIN
500mV/div
YIN
500mV/div
8
CIN
500mV/div
7
OUT
500mV/div
6
2.5
3.0
3.5
4.0
4.5
5.0
5.5
4µs/div
4µs/div
SUPPLY VOLTAGE (V)
OUT
500mV/div
_______________________________________________________________________________________
3
Video Y/C Summer with
Driver and Chroma Mute
MAX11503
Typical Operating Characteristics (continued)
(V
CC
= 3.0V, V
PSAVE
= V
CC
, V
CMUTE
= 0V, R
L
= 150Ω, AC-coupled, T
A
= +25°C, unless otherwise noted.)
FIELD SQUARE WAVE
(DC-COUPLED OUTPUT)
MAX11503 toc05
MAX11503 toc04
FREQUENCY RESPONSE
20
LUMA
0
CHROMA
RESPONSE (dB)
-20
YIN
500mV/div
-40
-60
OUT
500mV/div
-80
0.1
1
10
FREQUENCY (MHz)
100
1000
4ms/div
FIELD SQUARE WAVE
(AC-COUPLED OUTPUT)
MAX11503 toc06
FIELD SQUARE WAVE
(SAG-COUPLED OUTPUT)
MAX11503 toc07
V
CC
= 3V OR 5V
C
OUT
= 220µF
V
CC
= 5V, C
OUT
= 68µF,
C
SAG
= 33µF
YIN
500mV/div
YIN
500mV/div
OUT
500mV/div
4ms/div
4ms/div
OUT
500mV/div
DIFFERENTIAL GAIN
MAX11503 toc08
DIFFERENTIAL PHASE
0.3
DIFFERENTIAL PHASE (deg)
0.2
0.1
0
-0.1
-0.2
-0.3
MAX11503 toc09
0.2
0.4
DIFFERENTIAL GAIN (%)
0.1
0
-0.1
-0.2
1
2
3
4
5
6
7
-0.4
1
2
3
4
5
6
7
4
_______________________________________________________________________________________
Video Y/C Summer with
Driver and Chroma Mute
Pin Description
PIN
1
2
3
4
5
6
7
8
EP
NAME
YIN
GND
OUT
SAG
V
CC
PSAVE
CMUTE
CIN
—
Luma Input
Ground
Video Out
Sag Correction Input. Connect to OUT when AC- or DC-coupling video output. See Figure 1 to determine
capacitor value and circuit.
Power Supply. Bypass to GND with 0.1µF and 1µF capacitors.
Active-Low Power-Save Logic Input. Connect
PSAVE
to V
CC
for normal operation. Drive low to put device
into a low-power consumption mode.
Chroma Mute Logic Input. Connect CMUTE to ground for normal operation. Drive high to disable the
chroma buffer.
Chroma Input
Exposed Pad. Connect EP to ground.
FUNCTION
MAX11503
Detailed Description
The MAX11503 is a low-power video amplifier with a
Y/C summer and chroma mute. The device accepts an
S-video or Y/C input and sums the luma (Y) and chroma
(C) signals into a composite CVBS signal which can be
connected directly to a TV monitor. The MAX11503 drives
two terminated 75Ω video coax cables.
The MAX11503 features chroma mute, power save, and
SAG correction. Chroma mute disables the chroma
buffer. If the device is used to combine Y and C signals
in a camera application, chroma mute may be used in
low-light situations. This removes all chroma including
burst which causes a downstream composite video
decoder to interpret the video signal as luminance only,
thus improving image quality. Power-save puts the
device into a low-power consumption mode. SAG
correction allows small output capacitors to be used
in AC-coupled output applications.
The MAX11503 has a transparent clamp at YIN, allow-
ing the luma input to be AC- or DC-coupled. If the luma
input is DC-coupled, the sync tip must be at ground
and the video signal must be 1V
P-P
. For low-supply
voltages, ensure that the DC level of the input is low
enough to avoid clipping at the output. If the luma input
is AC-coupled, the clamp adjusts the luma signal’s
sync tip to ground at YIN. Use an AC-coupling capacitor
of 0.1µF.
The MAX11503 has an internal AC-coupling capacitor
at CIN, allowing the chroma input to be coupled directly
to CIN.
Chroma Mute
In applications using cameras that output composite
video, the video is always decoded by a downstream
composite decoder in a monitor or for further video
processing.
In low-light conditions, the camera video signal
becomes noisy. The high-frequency (less visible mono-
chrome) noise from the camera is transformed to low-
frequency highly visible colored noise by the normal
encode and decode blocks of composite video pro-
cessing. This is caused when the chroma information is
encoded onto a high-frequency subcarrier, mixed with
the luminance and the decoded. First, high-frequency
noise near the color subcarrier is down-converted to
low-frequency noise. Second, chroma separation by
comb filtering removes luminance noise, but correlates
the noise in phase with the chroma to become vertical
lines. These two effects cause highly visible and objec-
tional color noise. Hence, using a purely monochrome
signal is better looking than a color signal.
When pulled high, the chroma mute input disables all
chroma and burst and the device outputs a mono-
chrome video signal. This causes the downstream
decoder to recognize the video signal as monochrome.
Power-Save
Asserting
PSAVE
logic low puts the device into a
power-down mode, reducing the supply current to
0.5µA and minimizing power consumption. Connect
PSAVE
to V
CC
for normal operation.
_______________________________________________________________________________________
5
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