Package Options Include Plastic
Small-Outline Packages, Ceramic Chip
Carriers, and Standard Plastic and Ceramic
300-mil DIPs

description
These devices contain two independent J-K
positive-edge-triggered flip-flops. A low level at
the preset (PRE) or clear (CLR) inputs sets or
resets the outputs regardless of the levels of the
other inputs. When PRE and CLR are inactive
(high), data at the J and K input meeting the
setup-time requirements are transferred to the
outputs on the positive-going edge of the clock
pulse. Clock triggering occurs at a voltage level
and is not directly related to the rise time of the
clock pulse. Following the hold time interval, data
at the J and K inputs may be changed without
affecting the levels at the outputs. These versatile
flip-flops can perform as toggle flip-flops by
grounding K and trying J high. They also can
perform as D-type flip-flops if J and K are tied
together.
The SN54F109 is characterized for operation over
the full military temperature range of –55°C to
125°C. The SN74F109 is characterized for
operation from 0°C to 70°C.