Dedicated debouncer IC...

P

Pimpom

Guest
The MAX681* series of switch debouncers look useful but they\'re
quite pricey at >$1 for the single MAX6816 and several $$ for the
octal 6818. Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are
externally simple devices that have pins for each mechanical
switch and for the debounced output. Nothing else apart from Vcc
and ground. The 40ms debouncing is done internally without any
external component.
 
Pimpom <nobody@nowhere.com> wrote:
The MAX681* series of switch debouncers look useful but they\'re
quite pricey at >$1 for the single MAX6816 and several $$ for the
octal 6818. Are there any cheaper, easily available alternatives?
Click to expand...

Hex schmitt-triggers?
Most versatile solution would be a small uc.
--
Dipl.-Inform(FH) Peter Heitzer, peter.heitzer@rz.uni-regensburg.de
 
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.
Click to expand...

I used a maxim reset chip.... if you can live with the 140mS odd delay..
No doubt Microchip do something similar....

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
On 12/08/20 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite pricey at
$1 for the single MAX6816 and several $$ for the octal 6818. Are there any
cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally simple
devices that have pins for each mechanical switch and for the debounced output.
Nothing else apart from Vcc and ground. The 40ms debouncing is done internally
without any external component.
Click to expand...

It pains me to note...
https://cpldcpu.wordpress.com/2019/08/12/the-terrible-3-cent-mcu/
 
On 8/12/2020 1:56 AM, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite pricey at
$1 for the single MAX6816 and several $$ for the octal 6818. Are there any
cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally simple
devices that have pins for each mechanical switch and for the debounced output.
Nothing else apart from Vcc and ground. The 40ms debouncing is done internally
without any external component.
Click to expand...

MC14490?
 
On Wednesday, August 12, 2020 at 1:56:41 AM UTC-7, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re
quite pricey at >$1 for the single MAX6816 and several $$ for the
octal 6818. Are there any cheaper, easily available alternatives?
Click to expand...

How about a magnetic switch, with the hysteresis in the Hall chip?
TCS40nnn goes for under $0.20 in hundreds.
It used to be common to get these in pushbutton form for keypads,
but there\'s a dearth of supply of those nowadays (I\'ve got a bottle of
the suckers somewhere...).
 
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.
Click to expand...

Change the switch to SPDT, earth the centre and use 2 pullups with
cross coupled nands as a set reset FF. Instant action, no bounce.
 
On 8/12/2020 2:39 PM, Peter Heitzer wrote:
Pimpom <nobody@nowhere.com> wrote:
The MAX681* series of switch debouncers look useful but they\'re
quite pricey at >$1 for the single MAX6816 and several $$ for the
octal 6818. Are there any cheaper, easily available alternatives?

Hex schmitt-triggers?
Most versatile solution would be a small uc.
Click to expand...
I\'ve used both approches but they require external components
and/or programming. The MAX chips need neither.
 
On 8/12/2020 2:53 PM, TTman wrote:
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.

I used a maxim reset chip.... if you can live with the 140mS odd delay..
No doubt Microchip do something similar....
Click to expand...
Examples?
 
On 8/12/2020 3:04 PM, Don Y wrote:
On 8/12/2020 1:56 AM, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite pricey at
$1 for the single MAX6816 and several $$ for the octal 6818. Are there any
cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally simple
devices that have pins for each mechanical switch and for the debounced output.
Nothing else apart from Vcc and ground. The 40ms debouncing is done internally
without any external component.

MC14490?
Click to expand...
I know about the MC14490 and the single external capacitor is not
a big deal, but the price is no better than that of the MAX681x.
 
On 2020-08-12 04:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.
Click to expand...

There\'s the hoary old MC14490 hex contact bounce eliminator for about
the same money ($3.50 in reels). Alternatively, use an SPDT and an RS
flipflop, or a 10-ms RC and a Schmitt trigger.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On a sunny day (Wed, 12 Aug 2020 10:27:31 +0100) it happened Tom Gardner
<spamjunk@blueyonder.co.uk> wrote in <7COYG.919245$wVe.260011@fx47.ams4>:

On 12/08/20 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite pricey at
$1 for the single MAX6816 and several $$ for the octal 6818. Are there any
cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally simple
devices that have pins for each mechanical switch and for the debounced output.
Nothing else apart from Vcc and ground. The 40ms debouncing is done internally
without any external component.

It pains me to note...
https://cpldcpu.wordpress.com/2019/08/12/the-terrible-3-cent-mcu/
Click to expand...

https://cpldcpu.files.wordpress.com/2019/08/3-cent-mcu-1.png
Nice
I like the Padauk.
 
On 8/12/2020 3:45 PM, Andy Bennet wrote:
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.

Change the switch to SPDT, earth the centre and use 2 pullups with
cross coupled nands as a set reset FF. Instant action, no bounce.
Click to expand...
An SPDT switch is less common than an SPST one and the circuit
needs the pull-up resistors. Besides, if the switch has to be at
some distance from the FF, it needs two lines to connect the two.

There are various ways to achieve bounceless switching and I\'ve
used them before. What makes the MAX681x attractive is that it
can use common SPST switches and doesn\'t need any external
component. No µC either.
 
On 8/12/2020 4:17 PM, Phil Hobbs wrote:
On 2020-08-12 04:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.

There\'s the hoary old MC14490 hex contact bounce eliminator for about
the same money ($3.50 in reels). Alternatively, use an SPDT and an RS
flipflop, or a 10-ms RC and a Schmitt trigger.

Cheers

Phil Hobbs
Click to expand...
Please see my replies to Don Y and to Andy Bennet.
 
On 8/12/2020 4:20 PM, Jan Panteltje wrote:
On a sunny day (Wed, 12 Aug 2020 10:27:31 +0100) it happened Tom Gardner
spamjunk@blueyonder.co.uk> wrote in <7COYG.919245$wVe.260011@fx47.ams4>:

On 12/08/20 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite pricey at
$1 for the single MAX6816 and several $$ for the octal 6818. Are there any
cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally simple
devices that have pins for each mechanical switch and for the debounced output.
Nothing else apart from Vcc and ground. The 40ms debouncing is done internally
without any external component.

It pains me to note...
https://cpldcpu.wordpress.com/2019/08/12/the-terrible-3-cent-mcu/


https://cpldcpu.files.wordpress.com/2019/08/3-cent-mcu-1.png
Nice
I like the Padauk.
Click to expand...
Interesting. I don\'t remember using any Padauk product but I\'ve
used some by Holtek.
 
Pimpom wrote:

> Are there any cheaper, easily available alternatives?

The cheapest MCU with internal clock you can find?

Best regards, Piotr
 
On 2020-08-12 12:15, Andy Bennet wrote:
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal
6818. Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.

Change the switch to SPDT, earth the centre and use 2 pullups with cross
coupled nands as a set reset FF. Instant action, no bounce.
Click to expand...

Or simpler, less wiring, less ICs:
- Connect both ends of all SPDTs to GND and VCC
- Wire the contact to a non-inverting buffer input, with 330 Ohms
between output and input.
Only one signal wire per switch needed, and instant action.


/------ 330R ---\\
VCC ----o\\ | |\\ |
\\----+-----| >-------+--- out
GND ----o |/


Regards,
Arie
 
On 8/12/2020 3:32 AM, Pimpom wrote:
On 8/12/2020 3:04 PM, Don Y wrote:
On 8/12/2020 1:56 AM, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite pricey at
$1 for the single MAX6816 and several $$ for the octal 6818. Are there any
cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally simple
devices that have pins for each mechanical switch and for the debounced output.
Nothing else apart from Vcc and ground. The 40ms debouncing is done internally
without any external component.

MC14490?

I know about the MC14490 and the single external capacitor is not a big deal,
but the price is no better than that of the MAX681x.
Click to expand...

Never looked at its price. I\'m aware of it\'s existence solely because of
its presence in a design I was asked to critique. I indicated it should be
*removed* as it\'s functionality could be implemented cheaper and more
flexibly, elsewhere. (e.g., recognizing the switch action and responding
to it BEFORE incurring the cost of the debounce interval).

Spend the money you\'d be spending on the debounce chip on protection
networks to keep noise and ESD from entering your circuit via the
switch connections!
 
On Wed, 12 Aug 2020 15:54:16 +0530, Pimpom wrote:

On 8/12/2020 2:53 PM, TTman wrote:
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal
6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.

I used a maxim reset chip.... if you can live with the 140mS odd
delay..
No doubt Microchip do something similar....

Examples?
Click to expand...

Any of the 3 pin uP reset chips will work. You can get them
for $0.25 and less. You do have to have an external pulldown
from chip vcc to ground. Pushbutton interrupts vcc to the chip.
Reset output will go low V and then high after some time period, some
chips are 200ms, some 140, check the data sheets.

--
Chisolm
Texas-American
 
On Wed, 12 Aug 2020 15:54:16 +0530, Pimpom <nobody@nowhere.com> wrote:

On 8/12/2020 2:53 PM, TTman wrote:
On 12/08/2020 09:56, Pimpom wrote:
The MAX681* series of switch debouncers look useful but they\'re quite
pricey at >$1 for the single MAX6816 and several $$ for the octal 6818.
Are there any cheaper, easily available alternatives?

For those who are not familiar with the series, these are externally
simple devices that have pins for each mechanical switch and for the
debounced output. Nothing else apart from Vcc and ground. The 40ms
debouncing is done internally without any external component.

I used a maxim reset chip.... if you can live with the 140mS odd delay..
No doubt Microchip do something similar....

Examples?
Click to expand...

The MAX809 series has all sorts of uses. The best part is that you
don\'t have to buy them from Maxim.

But as a debouncer, you\'d need more parts. Some other POR chips might
not.

A Schmitt gate would need an RC per switch, which could be in quad
packs.

Why do you need to debounce?



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
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