The CD4021BC is an 8-stage parallel input/serial output
shift register. A parallel/serial control input enables individual
JAM inputs to each of 8 stages. Q outputs are available
from the sixth, seventh, and eighth stages. All outputs have
equal source and sink current capabilities and conform to
standard “B” series output drive.
When the parallel/serial control input is in the logical “0”
state, data is serially shifted into the register synchronously
with the positive transition of the clock. When the parallel/
serial control is in the logical “1” state, data is jammed into
each stage of the register asynchronously with the clock.
All inputs are protected against static discharge with diodes
to VDD and VSS.
Features

Wide supply voltage range: 3.0V to 15V

High noise immunity: 0.45 VDD (typ.)

Low power TTL compatibility:
Fan out of 2 driving 74L or 1 driving 74LS

5V–10V–15V parametric ratings

Symmetrical output characteristics

Maximum input