19-4238; Rev 2; 11/08
KIT
ATION
EVALU
BLE
AVAILA
Low-Power Video Switches
for Dual SCART Connectors
General Description
Features
♦
Dual SCART Support for Video Signals
♦
Supports CVBS Input from TV SCART (MAX9656)
♦
Reconstruction Filters with 9.5MHz Passband and
47dB Attenuation at 27MHz
♦
Fixed Gain of 2V/V
♦
Input Sync-Tip Clamps
♦
2.7V to 3.6V Single-Supply Operation
MAX9655/MAX9656
The MAX9655/MAX9656 dual SCART switches route
video signals between a set-top box decoder chip and
two external SCART connectors. Under the control of the
TV_SEL logic input, the MAX9655 selects whether the
CVBS and RGB signals from the encoder or the VCR
SCART are routed to the TV SCART. The CVBS signal
from the encoder is always routed to the VCR SCART.
The MAX9656 is similar to the MAX9655 except that
under the control of the VCR_SEL logic input, the
MAX9656 selects whether the CVBS signal from the
encoder or the TV SCART is routed to the VCR SCART.
The MAX9656 also features a low-power shutdown
mode, in which quiescent current falls to 35µA.
The incoming video signals must be AC-coupled to the
inputs, which have sync-tip clamps to set the internal
DC level. After the input stages, multiplexers select
which video signals are routed to the reconstruction fil-
ters and output amplifiers. The reconstruction filters are
optimized for standard-definition signals and typically
have ±1dB passband flatness out to 9.5MHz and 47dB
attenuation at 27MHz.
The amplifiers have 2V/V gain, and the outputs can be
DC-coupled to a 75Ω load, which is the equivalent of
two video loads, or AC-coupled to a 150Ω load.
Ordering Information
PART
MAX9655AEE+
MAX9656AEP+
PIN-PACKAGE
16 QSOP
20 QSOP
TV SCART CVBS
RETURN SUPPORT
No
Yes
Note:
All devices are specified over the -40°C to +125°C oper-
ating temperature range.
+Denotes
a lead-free/RoHS-compliant package.
Applications
SCART Set-Top Boxes
Pin Configurations and Typical Application Circuits appear
at end of data sheet.
Functional Diagram
V
DD
TV_SEL
0
ENC_B_IN
1
ENC_G_IN
UNKNOWN
BIAS
ENC_R_IN
1
ENC_CVBS_IN
CLAMPREF
0
VCR_B_IN
1
VCR_G_IN
CLAMPREF
0
VCR_R_IN
1
VCR_CVBS_IN
CLAMPREF
BUFFER
0
LPF
2V/V
VCR_CVBS_OUT
BUFFER
LPF
2V/V
TV_CVBS_OUT
BUFFER
LPF
2V/V
TV_R_OUT
CLAMPREF
0
BUFFER
LPF
2V/V
300mV
TV_G_OUT
BUFFER
LPF
2V/V
MAX9655
TV_B_OUT
TV_SEL
CLAMPREF
GND
________________________________________________________________
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.
Low-Power Video Switches
for Dual SCART Connectors
MAX9655/MAX9656
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
V
DD
to GND ...........................................................-0.3V to +4V
All Video and Logic Input Pins..................(GND - 0.3V) to +4V
Duration of Output Short Circuit to V
DD
or GND ........Continuous
Continuous Input Current
All Video and Logic Input Pins .....................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW
20-Pin QSOP (derate 9.1mW/°C above +70°C)............727mW
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
(V
DD
= 3.3V, V
GND
= 0, V
SHDN
= V
DD
, VCR_SEL = V
DD
, TV_SEL = V
DD
, R
L
= 150Ω to GND, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
Quiescent Supply Current
Shutdown Supply Current
Input Voltage
Input Resistance
Sync-Tip Clamp Level
Input Voltage Range
V
CLP
Guaranteed by output-
voltage swing
2.7V
≤
V
DD
≤
3.6V
3.0V
≤
V
DD
≤
3.6V
Sync-tip clamp; percentage reduction in
sync pulse (0.3V
P-P
); guaranteed by input
clamping current measurement
1
300
V
DD
= 2.7V, 0V
≤
V
IN
≤
1.05V
V
DD
= 3.0V, 0V
≤
V
IN
≤
1.2V
1.96
1.96
-2
0.218
0.3
2.1
2.1
2.4
2.4
2.1
V
P-P
2
2
2.04
V/V
2.04
+2
0.39
%
V
SYMBOL
V
DD
I
DD
I
SHDN
No load
V
SHDN
= TV_SEL = VCR_SEL = GND
(MAX9656 only)
Unselected input
Unselected input
0.23
CONDITIONS
Guaranteed by power-supply rejection test
MIN
2.7
TYP
3.3
21
35
V
DD
/3
222
0.3
0.39
1.05
1.2
2
2
MAX
3.6
45
70
UNITS
V
mA
µA
V
kΩ
V
V
P-P
Sync Crush
Input Clamping Current
Maximum Input Source
Resistance
%
µA
Ω
DC Voltage Gain
A
V
R
L
= 150Ω to GND
(Note 2)
DC Gain Mismatch
Output Level
Guaranteed by output-voltage swing
Measured at output, C
IN_
= 0.1µF to GND
Measured at output, V
DD
= 2.7V, V
IN
=
V
CLP
to (V
CLP
+1.05V), R
L
= 150Ω to -0.2V
Measured at output, V
DD
= 2.7V, V
IN
=
V
CLP
to (V
CLP
+1.05V), R
L
= 150Ω to V
DD
/2
Output-Voltage Swing
Measured at output, V
DD
= 3.0V, V
IN
=
V
CLP
to (V
CLP
+1.2V), R
L
= 150Ω to -0.2V
Measured at output, V
DD
= 3.0V, V
IN
=
V
CLP
to (V
CLP
+1.2V), R
L
= 150Ω to V
DD
/2
Measured at output, V
DD
= 3.135V, V
IN
=
V
CLP
to (V
CLP
+1.05V), R
L
= 75Ω to -0.2V
2
_______________________________________________________________________________________
Low-Power Video Switches
for Dual SCART Connectors
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 3.3V, V
GND
= 0, V
SHDN
= V
DD
, VCR_SEL = V
DD
, TV_SEL = V
DD
, R
L
= 150Ω to GND, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Output Short-Circuit Current
Output Resistance
Power-Supply Rejection Ratio
R
OUT
SYMBOL
CONDITIONS
Short to GND (sourcing)
Short to V
DD
(sinking)
V
OUT
= 1.5V, -10mA
≤
I
LOAD
≤
+10mA
2.7V
≤
V
DD
≤
3.6V
f = 1MHz, 100mV
P-P
V
OUT
= 2V
P-P
, reference frequency is
100kHz, ±1dB passband flatness
Standard-Definition
Reconstruction Filter
f = 5.5MHz
V
OUT
= 2V
P-P
, reference
frequency is 100kHz
f = 9.5MHz
f = 10MHz
f = 27MHz
Differential Gain
DG
5-step modulated staircase of 129mV step
size and 286mV peak-to-peak subcarrier
amplitude, f = 4.43MHz
5-step modulated staircase of 129mV step
size and 286mV peak-to-peak subcarrier
amplitude, f = 4.43MHz
100kHz
≤
f
≤
5MHz, outputs are 2V
P-P
100kHz
≤
f
≤
5MHz
2T = 200ns
2T = 200ns; bar time is 18µs; the beginning
2.5% and the ending 2.5% of the bar time
are ignored
2T = 200ns; bar time is 18µs; the beginning
2.5% and the ending 2.5% of the bar time
are ignored
5-step staircase
f = 5.5MHz
f = 15kHz
f = 4.43MHz
f = 30MHz
48
MIN
TYP
140
70
0.2
64
20
9.5
0.1
-1
-3
-47
0.4
%
dB
MAX
UNITS
mA
Ω
dB
MHz
MAX9655/MAX9656
Differential Phase
Group-Delay Distortion
Peak Signal to RMS Noise
2T Pulse Response
2T Bar Response
DP
0.45
9
71
0.2
0.2
deg
ns
dB
K%
K%
2T Pulse-to-Bar K Rating
Nonlinearity
Output Impedance
All-Hostile Crosstalk
Output-to-Input Crosstalk
0.3
0.1
8.07
-82
-78
-68
0.3 x
V
DD
0.7 x
V
DD
10
K%
%
Ω
dB
dB
LOGIC SIGNALS (MAX9655: TV_SEL, MAX9656: TV_SEL, VCR_SEL,
SHDN)
Logic-Low Threshold
Logic-High Threshold
Logic Input Current
V
IL
V
IH
I
IN
T
A
= +25°C
T
A
= +25°C
T
A
= +25°C
V
V
µA
Note 1:
All devices are 100% production tested at T
A
= +25°C. Specifications over temperature limits are guaranteed by design.
Note 2:
Voltage gain (A
V
) is a two-point measurement in which the output-voltage swing is divided by the input-voltage swing.
_______________________________________________________________________________________
3
Low-Power Video Switches
for Dual SCART Connectors
MAX9655/MAX9656
Typical Operating Characteristics
(V
DD
= 3.3V, V
GND
= 0, V
SHDN
= V
DD
, R
L
= 150Ω to GND, T
A
= +25°C.)
SMALL-SIGNAL GAIN
vs. FREQUENCY
V
IN
= 50mV
P-P
NOTE: GAIN IS NORMALIZED TO 0dB
MAX9655 toc01
SMALL-SIGNAL GAIN FLATNESS
vs. FREQUENCY
2
1
0
GAIN (dB)
-1
-2
-3
-4
-5
-6
-7
V
IN
= 50mV
P-P
NOTE: GAIN IS NORMALIZED TO 0dB
MAX9655 toc02
10
5
0
-5
GAIN (dB)
-10
-15
-20
-25
-30
-35
-40
-45
-50
3
100k
1M
10M
100M
100k
1M
10M
100M
FREQUENCY (Hz)
FREQUENCY (Hz)
LARGE-SIGNAL GAIN
vs. FREQUENCY
V
IN
= 1V
P-P
NOTE: GAIN IS NORMALIZED TO 0dB
MAX9655 toc03
LARGE-SIGNAL GAIN FLATNESS
vs. FREQUENCY
2
1
0
GAIN (dB)
-1
-2
-3
-4
-5
-6
-7
V
IN
= 1V
P-P
NOTE: GAIN IS NORMALIZED TO 0dB
MAX9655 toc04
10
5
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
GAIN (dB)
3
100k
1M
10M
100M
100k
1M
10M
100M
FREQUENCY (Hz)
FREQUENCY (Hz)
VIDEO CROSSTALK
vs. FREQUENCY
MAX9655 toc05
VIDEO GROUP DELAY DISTORTION
vs. FREQUENCY
120
110
100
90
GROUP DELAY (ns)
80
70
60
50
40
30
20
10
0
V
IN
= 1V
P-P
NOTE: GAIN IS NORMALIZED TO 0dB
MAX9655 toc06
0
-20
-40
GAIN (dB)
-60
V
IN
= 1V
P-P
NOTE: GAIN IS NORMALIZED TO 0dB
ALL-HOSTILE
-80
-100
-120
100k
1M
10M
100M
FREQUENCY (Hz)
2 ADJACENT CHANNELS
1 ADJACENT CHANNEL
100k
1M
10M
100M
FREQUENCY (Hz)
4
_______________________________________________________________________________________
Low-Power Video Switches
for Dual SCART Connectors
Typical Operating Characteristics (continued)
(V
DD
= 3.3V, V
GND
= 0, V
SHDN
= V
DD
, R
L
= 150Ω to GND, T
A
= +25°C.)
VIDEO PSRR
vs. FREQUENCY
V
DD
= 3.3V + 100mV
P-P
MAX9655 toc07
MAX9655/MAX9656
VOLTAGE GAIN
vs. TEMPERATURE
2.08
2.06
VOLTAGE GAIN (V/V)
2.04
2.02
2.00
1.98
1.96
1.94
1.92
1.90
MAX9655 toc08
0
-10
-20
PSRR (dB)
-30
-40
-50
-60
-70
-80
2.10
100k
1M
10M
100M
-50
-25
0
25
50
75
100
125
FREQUENCY (Hz)
TEMPERATURE (°C)
DIFFERENTIAL GAIN
DIFFERENTIAL GAIN (%)
DIFFERENTIAL GAIN (%)
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
0
0.8
0.6
0.4
0.2
0
-0.2
-0.4
0
1
2
3
1
2
3
f = 3.58MHz
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
0
0.8
0.6
0.4
0.2
0
-0.2
-0.4
0
MAX9655 toc09
DIFFERENTIAL GAIN
f = 4.43MHz
MAX9655 toc10
4
5
1
2
3
4
5
DIFFERENTIAL PHASE (deg)
DIFFERENTIAL PHASE (deg)
DIFFERENTIAL PHASE
f = 3.58MHz
DIFFERENTIAL PHASE
f = 4.43MHz
4
5
1
2
3
4
5
2T RESPONSE
MAX9655 toc11
12.5T RESPONSE
MAX9655 toc12
IN
200mV/div
IN
200mV/div
OUT
400mV/div
OUT
400mV/div
100ns/div
400ns/div
_______________________________________________________________________________________
5
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