MC74LVXT4052
www.onsemi.com
11
APPLICATIONS INFORMATION
The Channel Select and Enable control pins should be at
V
CC
or GND logic levels. V
CC
being recognized as a logic
high and GND being recognized as a logic low. In this
example:
V
CC
= )5 V = logic high
GND = 0 V = logic low
The maximum analog voltage swing is determined by the
supply voltages V
CC
and V
EE
. The positive peak analog
voltage should not exceed V
CC
. Similarly, the negative peak
analog voltage should not go below V
EE
. In this example,
the difference between V
CC
and V
EE
is five volts. Therefore,
using the configuration of Figure 20, a maximum analog
signal of five volts peak−to−peak can be controlled. Unused
analog inputs/outputs may be left floating (i.e., not
connected). However, tying unused analog inputs and
outputs to V
CC
or GND through a low value resistor helps
minimize crosstalk and feedthrough noise that may be
picked up by an unused switch.
Although used here, balanced supplies are not a
requirement. The only constraints on the power supplies are
that:
V
EE
− GND = 0 to *6 volts
V
CC
− GND = 2.5 to 6 volts
V
CC
− V
EE
= 2.5 to 6 volts
and V
EE
v GND
When voltage transients above V
CC
and/or below V
EE
are
anticipated on the analog channels, external Germanium or
Schottky diodes (D
x
) are recommended as shown in
Figure 21. These diodes should be able to absorb the
maximum anticipated current surges during clipping.
ANALOG
SIGNAL
Figure 19. Application Example
ON
6
7
8
16
ANALOG
SIGNAL
+3.0 V
−3.0 V
+3.0 V
−3.0 V
11
10
9
TO EXTERNAL CMOS
CIRCUITRY 0 to 3.0 V
DIGITAL SIGNALS
−3.0 V
Figure 20. Application Example
ANALOG
SIGNAL
ON
6
7
8
16
ANALOG
SIGNAL
+5 V
GND
+5 V
GND
11
10
9
TO EXTERNAL CMOS
CIRCUITRY 0 to 5 V
DIGITAL SIGNALS
ON/OFF
7
8
16
V
CC
V
EE
D
x
V
CC
D
x
V
EE
D
x
V
CC
D
x
V
EE
Figure 21. External Germanium or Schottky Clipping Diodes
