Maker Pro
Maker Pro

any substitute ofr JK flip flop??

A

Ankur

Jan 1, 1970
0
After lot many attempts , i m unable to use the JK flip flop .. don't
know wht the problem is !
neways, i wish 2 get something which has a control input and toggles
at the falling edge. Is there any other device/circuit through which i
can achieve this ??
(Pls tellme those which require lesser no. of components as i m
running short of breadboard space)

TIA
ankur
 
C

CFoley1064

Jan 1, 1970
0
Subject: any substitute ofr JK flip flop??
From: [email protected] (Ankur)
Date: 2/23/2004 2:58 PM Central Standard Time
Message-id: <[email protected]>

After lot many attempts , i m unable to use the JK flip flop .. don't
know wht the problem is !
neways, i wish 2 get something which has a control input and toggles
at the falling edge. Is there any other device/circuit through which i
can achieve this ??
(Pls tellme those which require lesser no. of components as i m
running short of breadboard space)

TIA
ankur

Unless you're running short of patience, you might want to give that J-K FF
another try. You don't indicate what chip you're using, or what your power
supply voltage is, so we're kind of in the dark. Here's what to do to make a
74HC76 act like a toggle FF with NGT clock transitions: (read in fixed font or
use M$ Notepad)

J-K FF Set as a Toggle FF
VCC
+
VCC |
+ .-----o-----.
| | Set |
'--o J Q o
| 1/2 |
| 74HC76 |
Input Clock | |
o------------o CLK' |
VCC | |
+ | |
| | |
'--o K Q'o
| |
| Reset |
'-----o-----'
|
VCC |
+ |
| |
| |
'---'

The old 74 series pinouts are probably a good choice because of your
requirement of a NGT clock. If this doesn't work for you, check your pinouts
-- you might have things wired wrong. Also, the IC might be damaged (believe
it or not, it does happen!)

The other J-K FFs have a similar setup, although some like the 7473 and 74107
have clear only. You could also use a D FF, but on the standard TTL pinout
ICs, there is usually a common clock for all the FFs. Usually you want a
little more latitude.

If you're using the 7476, there are a couple of gotchas -- read the data sheet!
Also, make sure you have clean, debounced fast rise- and fall-time clock
inputs -- that can cause major headaches.

Good luck
Chris
 
K

Keith R. Williams

Jan 1, 1970
0
After lot many attempts , i m unable to use the JK flip flop .. don't
know wht the problem is !
neways, i wish 2 get something which has a control input and toggles
at the falling edge. Is there any other device/circuit through which i
can achieve this ??
(Pls tellme those which require lesser no. of components as i m
running short of breadboard space)

You can use a DFF ('74, or some such) with the 'Qbar' tied back
to the 'D' for a toggle. If you *really* need negative edge
triggering you can wire up the other half of the package as an
inverter (using the Set/Reset pins).
 
Top