FMS6501MSA28X Fairchild Semiconductor, FMS6501MSA28X Datasheet - Page 11

• Manufacturer Part Number: FMS6501MSA28X
• Description: IC VIDEO SW MATRIX 12X9 28SSOP
• Manufacturer: Fairchild Semiconductor
• Type: Video Switch, 12-Input 9-Outputr

Specifications of FMS6501MSA28X

• Applications: Set-Top Boxes
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: FMS6501MSA28XTR; FMS6501MSA28X_NL; FMS6501MSA28X_NLTR; FMS6501MSA28X_NLTR

© 2004 Fairchild Semiconductor Corporation
FMS6501 Rev. 1.0.4
Thermal issues are significantly reduced with AC-cou-
pled outputs, alleviating special PC layout requirements.
Each of the outputs can be independently powered down
and placed in a high-impedance state with the ENABLE
bit. This function can be used to mute video signals, to
parallel multiple FMS6501 outputs, or to save power.
When the output amplifier is disabled, the high-imped-
ance output presents a 3kΩ load to ground. The output
amplifier typically enters and recovers from the power-
down state in less than 300ns after being programmed.
When an output channel is not connected to an input, the
input to that channel’s amplifier is forced to approxi-
mately 150mV. The output amplifier is still active unless
specifically disabled by the I
levels depend on the programmed gain for that channel.
Crosstalk
Crosstalk is an important consideration when using the
FMS6501. Input and output crosstalk are defined to rep-
resent the two major coupling modes in a typical applica-
tion. Input crosstalk is crosstalk in the input pins and
switches when the interfering signal drives an open
switch. It is dominated by inductive coupling in the pack-
age lead frame between adjacent leads. It decreases
rapidly as the interfering signal moves farther away from
the pin adjacent to the input signal selected. Output
crosstalk is coupling from one driven output to another
active output. It decreases with increasing load imped-
ance, as it is caused mainly by ground and power cou-
pling between output amplifiers. If a signal is driving an
open switch, its crosstalk is mainly input crosstalk. If it is
driving a load through an active output, its crosstalk is
mainly output crosstalk.
Input and output crosstalk measurements are performed
with the test configuration shown in Figure 12.
TERMINATION
IN2 - IN12 are
AC-Term to
ground with
75
IN1 = 1Vpp
Open switch
for input
crosstalk
Close switch
for output
crosstalk
IN12
Figure 12. Test Configuration for Crosstalk
IN1
Gain = 6dB
OUT1 = 2.0Vpp
Bias
Bias
OUT1
Input crosstalk from IN1
to OUTx
Output crosstalk from
OUT1 to OUTx
2
C interface. Voltage output
OUT9
11
For input crosstalk, the switch is open. All inputs are in
bias mode. Channel 1 input is driven with a 1V
while all other inputs are AC terminated with 75Ω. All out-
puts are enabled and crosstalk is measured from IN1 to
any output.
For output crosstalk, the switch is closed. Crosstalk from
OUT1 to any output is measured.
Crosstalk from multiple sources into a given channel was
measured with the setup shown in Figure 6. Input IN1 is
driven with a 1V
puts Out1 to Out8. Input In9 is driven with a secondary,
asynchronous, gray-field video signal, and is connected
to Out9. All other inputs are AC terminated with 75Ω.
Crosstalk effects on the gray field are measured and cal-
culated with respect to a standard 1V
at the load.
If not all inputs and outputs are needed, avoid using
adjacent channels, where possible, to reduce crosstalk.
Disable all unused channels to further reduce crosstalk
and power dissipation.
IN1 driven with
SD videio 1Vpp
IN9 driven with
asynchronous
SD video 1Vpp
IN2-8 + IN10-12
driven with
AC term to GND
with 75
Figure 13. Test Configuration for Multi-Channel
TERMINATION
IN9
IN12
IN1
Gain = 6dB
OUT1 = 2.0Vpp
Bias
Bias
Bias
pp
pulse source and is connected to out-
OUT1
Crosstalk
Measure crosstalk from
Channels 1-8 into Channel 9
pp
output measured
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OUT9
pp
signal,