MC74LVXT8051
http://onsemi.com
8
R
L
Figure 12. Crosstalk Between Any Two
Switches, Test Set−Up
Figure 13. Power Dissipation Capacitance,
Test Set−Up
Figure 14a. Total Harmonic Distortion, Test Set−Up Figure 14b. Plot, Harmonic Distortion
0
-10
-20
-30
-40
-50
- 100
1.0 2.0 3.125
FREQUENCY (kHz)
dB
-60
-70
-80
-90
FUNDAMENTAL FREQUENCY
DEVICE
SOURCE
ON
6
8
16
C
L
*
*Includes all probe and jig capacitance
OFF
R
L
R
L
V
IS
R
L
C
L
*
V
OS
f
in
0.1mF
ON/OFF
6
8
16
V
CC
CHANNEL SELECT
NC
COMMON O/I
OFF/ON
ANALOG I/O
V
CC
A
11
V
CC
ON
6
8
16
V
CC
0.1mF
C
L
*
f
in
R
L
TO
DISTORTION
METER
*Includes all probe and jig capacitance
V
OS
V
IS
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
= +5V = logic high
GND = 0V = logic low
The maximum analog voltage swing is determined by the
supply voltage V
CC
. The positive peak analog voltage
should not exceed V
CC
. Similarly, the negative peak analog
voltage should not go below GND. In this example, the
difference between V
CC
and GND is five volts. Therefore,
using the configuration of Figure 15, 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
CC
− GND = 2 to 6 volts
When voltage transients above V
CC
and/or below GND
are anticipated on the analog channels, external Germanium
or Schottky diodes (D
x
) are recommended as shown in
Figure 16. These diodes should be able to absorb the
maximum anticipated current surges during clipping.
