EL4332C
Triple 2:1 300 MHz Mux-Amp AV =2
used, a 220Ω to 330Ω resistor to the -5.2V rail would
have the same effect.
When interstage attenuators are used, the values should
be kept down in the region of 50Ω–300Ω. This is to pre-
vent a combination of circuit board stray capacitance
and the EL4332C’s input capacitance forming a signifi-
cant pole. For example, if instead of 100Ω as shown,
resistors of 1 kΩ had been used, and assuming 3 pF of
stray and 3 pF of input capacitance, a pole would be
formed at about 53 MHz.
Expanding the Multiplexer
In Figure 4, a 3:1 multiplexer circuit is shown. The
expansion to more inputs is very straight forward. Since
the EL4332C has a fixed gain of 2, interstage attenuators
may be required as shown in Figure 3. The truth table for
the 3:1 multiplexer select lines is:
X
0
Y
0
Mux Output
R3, G3, B3
R2, G2, B2
R1, G1, B1
0
1
1
X
Figure 4. Typical Connection for a 3:1 Component Video Multiplexer
11
ELANTEC [ ELANTEC SEMICONDUCTOR ]
