el4453c ETC-unknow, el4453c Datasheet - Page 10

• Manufacturer Part Number: el4453c
• Description: Video Fader
• Manufacturer: ETC-unknow

Fade-Control Characteristics
The quantity V
bounded as
externally applied voltages often exceed this
range
around
does not clip abruptly below the 0%-V
age or above the 100% – V
drive of 0 3V must be applied to V
truly 0% or 100% Because the 0%
V
they are extrapolated from two points measured
inside the slope of the gain transfer curve Gener-
ally an applied V
will assure the full span of numerical
The fade control has a small-signal bandwidth
equal to the V
load recovery resolves in about 20 ns
Input Connections
The input transistors can be driven from resistive
and capacitive sources but are capable of oscilla-
tion when presented with an inductive input It
takes about 80 nH of series inductance to make
the inputs actually oscillate equivalent to four
inches of unshielded wiring or about six inches of
unterminated input transmission line The oscil-
lation has a characteristic frequency of 500 MHz
Often placing one’s finger (via a metal probe) or
an oscilloscope probe on the input will kill the
oscillation Normal high frequency construction
obviates any such problems where the input
source is reasonably close to the fader input If
this is not possible one can insert series resistors
of around 51
Signal Amplitudes
Signal input common-mode voltage must be be-
tween (V
linearity Additionally the differential voltage on
any input stage must be limited to
vent damage The differential signal range is
stantially constant with temperature
s
g
EL4453C
Video Fader
FADE
V
2V in the EL4453C The input range is sub-
FADE s
b
Actually
levels cannot be precisely determined
b
1V and
)
b
a
1 and 0
1
IN
to de-Q the inputs
2 5V and (V
FADE
s
FADE
a
channel bandwidth and over-
V
the gain transfer function
1V is ‘‘soft’’ that is the gain
FADE s
s
in the above equations is
range of
F
s
FADE
a
1
1 even though the
)
b
b
FADE
level An over-
1 5V to
2 5V to ensure
g
e
FADE
6V to pre-
or 100%-
to obtain
a
b
volt-
1 5V
1
10
The Ground Pin
The ground pin draws only 6
current and may be biased anywhere between
(V
is connected to the IC’s substrate and frequency
compensation components It serves as a shield
within the IC and enhances input stage CMRR
and channel-to-channel isolation over frequency
and if connected to a potential other than
ground it must be bypassed
Power Supplies
The EL4453C works well on any supplies from
voltages as long as the requirements of the GND
pin are observed (see the Ground Pin section for
a discussion) The supplies should be bypassed
close to the device with short leads 4 7 F tanta-
lum capacitors are very good and no smaller by-
passes need be placed in parallel Capacitors as
small as 0 01
rents flow
Singe-polarity supplies such as
can be used where the ground pin is connected to
will have to have their levels shifted above
ground to accommodate the lack of negative sup-
ply
The dissipation of the fader increases with power
supply voltage and this must be compatible with
the package chosen This is a close estimate for
the dissipation of a circuit
P
where I
g
a
D
3V to
5V and V
b
e
)
2
a
c
V
V
R
2 5V and (V
g
V
S
S
O
PAR
S
(assumed equal)
loading the output
15V The supplies may be of different
max is the maximum supply current
is the
b
is the output voltage
max
to ground The inputs and outputs
is the parallel of all resistors
F can be used if small load cur-
c
g
V
a
supply voltage
S
a
)
(V
b
S
3 5V The ground pin
b
V
O
a
A maximum DC
)
12V with
c
V
O
R
PAR
a
5V