SN54ALS109A, SN54AS109A, SN74ALS109A, SN74AS109A
DUAL J-K POSITIVE-EDGE-TRIGGERED FLIP-FLOPS
WITH CLEAR AND PRESET
SDAS198B – APRIL 1982 – REVISED AUGUST 1995
Copyright  1995, Texas Instruments Incorporated
1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
• Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
TYPE
TYPICAL MAXIMUM
CLOCK
FREQUENCY
(MHz)
TYPICAL POWER
DISSIPATION
PER FLIP-FLOP
(mW)
′ALS109A 50 6
′AS109A 129 29

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 inputs meeting the
setup-time requirements are transferred to the
outputs on the positive-going edge of the clock
(CLK) 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 can be changed without
affecting the levels at the outputs. These versatile
flip-flops can perform as toggle flip-flops by
grounding K and tying J high. They also can
perform as D-type flip-flops if J and K are tied
together.
The SN54ALS109A and SN54AS109A are characterized for operation over the full military temperature range
of –55°C to 125°C. The SN74ALS109A and SN74AS109A are characterized for operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS OUTPUTS
PRE CLR CLK J K Q Q
L H X X X H L
H LXXXLH
LLXXXH
†
H
†
HH↑LLLH
HH↑H L Toggle
H H ↑ LHQ0Q0
HH↑HHHL
HHLXXQ0 Q0
†
The output levels in this configuration are not specified to
meet the minimum levels for V
OH
if the lows at PRE and
CLR are near V
IL
maximum. Furthermore, this
configuration is nonstable; that is, it does not persist when
either PRE or CLR returns to its inactive (high) level.
SN54ALS109A, SN54AS109A ...J PACKAGE
SN74ALS109A, SN74AS109A ...D OR N PACKAGE
(TOP VIEW)
SN54ALS109A, SN54AS109A . . . FK PACKAGE
(TOP VIEW)
NC – No internal connection
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1CLR
1J
1K
1CLK
1PRE
1Q
1Q
GND
V
CC
2CLR
2J
2K
2CLK
2PRE
2Q
2Q
3212019
910111213
4
5
6
7
8
18
17
16
15
14
2J
2K
NC
2CLK
2PRE
1K
1CLK
NC
1PRE
1Q
1J 1CLR NC
2Q 2Q
V 2CLR
1Q
GND
NC
CC
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.