Motorola CMOS Logic, Руководство пользователя, Страница: 91 / 571

MOTOROLA CMOS LOGIC DATA
6–53
MC14016B
APPLICATIONS INFORMATION
Figure A illustrates use of the Analog Switch. The 0–to–5 V
Digital Control signal is used to directly control a 5 Vp–p ana-
log signal.
The digital control logic levels are determined by VDD and
VSS. The VDD voltage is the logic high voltage; the VSS volt-
age is logic low. For the example, VDD = +5 V logic high at
the control inputs; VSS = GND = 0 V logic low.
The maximum analog signal level is determined by VDD
and VSS. The analog voltage must not swing higher than
VDD or lower than VSS.
The example shows a 5 Vp–p signal which allows no
margin at either peak. If voltage transients above VDD and/or
below VSS are anticipated on the analog channels, external
diodes (Dx) are recommended as shown in Figure B. These
diodes should be small signal types able to absorb the
maximum anticipated current surges during clipping.
The absolute maximum potential difference between VDD
and VSS is 18.0 V. Most parameters are specified up to 15 V
which is the
recommended maximum difference between
VDD and VSS.
Figure A. Application Example
+ 5 V
VDD VSS
SWITCH
IN
SWITCH
OUT
5 Vp–p
ANALOG SIGNAL
0–TO–5 V DIGITAL
CONTROL SIGNALS
+ 5 V
EXTERNAL
CMOS
DIGITAL
CIRCUITRY
5 Vp–p
ANALOG SIGNAL
MC14016B
+ 5.0 V
+ 2.5 V
GND
Figure B. External Germanium or Schottky Clipping Diodes
VDD VDD
Dx
Dx
Dx
Dx
VSS VSS
SWITCH
IN
SWITCH
OUT