MC74VHCT4051

VHC Data – Advanced CMOS Logic

DL203 — Rev 2

9

MOTOROLA

RL

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)

–60

–70

–80

–90

FUNDAMENTAL FREQUENCY

DEVICE

SOURCE

ON

6

8

16

CL*

*Includes all probe and jig capacitance

OFF

RL

RL

VIS

RL

CL*

VOS

fin

0.1

µF

ON/OFF

6

8

16

VCC

CHANNEL SELECT

NC

COMMON O/I

OFF/ON

ANALOG I/O

VCC

A

11

VCC

ON

6

8

16

VCC

0.1

µF

CL*

fin

RL

TO

DISTORTION

METER

*Includes all probe and jig capacitance

VOS

VIS

APPLICATIONS INFORMATION

The Channel Select and Enable control pins should be at

VCC or GND logic levels. VCC being recognized as a logic

high and GND being recognized as a logic low. In this exam-

ple:

VCC = +5V = logic high

GND = 0V = logic low

The maximum analog voltage swing is determined by the

supply voltage VCC. The positive peak analog voltage should

not exceed VCC. Similarly, the negative peak analog voltage

should not go below GND. In this example, the difference

between VCC 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). How-

ever, tying unused analog inputs and outputs to VCC 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 require-

ment. The only constraints on the power supplies are that:

VCC – GND = 2 to 6 volts

When voltage transients above VCC and/or below GND

are anticipated on the analog channels, external Germanium

or Schottky diodes (Dx) are recommended as shown in Fig-

ure 16. These diodes should be able to absorb the maximum

anticipated current surges during clipping.