High-Voltage Schmitt Trigger Buffer Options | 74HC7014 Hex Inverter Alternative

[Jdo300]

Hello All,

I was just wondering if anyone knows of a different version of the 74HC7014 Hex non-inverting Schmitt-trigger buffer chip that can run on up to 9V? This one only goes up to 6V. I know I could easily use a voltage divider or a regulator to handle it but if there is a higher voltage one out there, it would save me the extra components.

Thanks,
Jason O

 

[xez]

The old 4000 series metal gate CMOS ICs can run on 9V;
the 40106 part is a hex schmitt trigger input inverter chip
similar to what you've been using.

I imagine that digikey.com, mouser.com, newark, et. al.
could still provide some of those parts for you.

They run more slowly in maximum frequency than the
newer 74HC series parts, but they're all in excess of a
couple of MHz so you should have no trouble using it in
your circuit.

 

[xez]

http://www.fairchildsemi.com/pf/CD/CD40106BC.html
http://www.mouser.com/search/ProductDetail.aspx?R=CD40106BCNvirtualkey51210000virtualkey512-CD40106BCN

There you go.

 

[Jdo300]

Hi Xez,

Thanks for the heads up on that. I will specifically need the Hex, non-inverting Schmitt triggers if they have them. I did my original tests using a 74LS14 IC which worked fine but I had to use some extra gates to convert the inverted logic output to the non-inverted one.

Here's the ultimate circuit scheme I'm going for.

Thanks,
Jason O

 

[xez]

oops I posted the previous message before I saw your
update about wanting non-inverting.
I'll have a look at schmitt buffers vs inverters and post
back.

Though you can use 2 series connected inverters
(double inversion = no inversion) and still get 3 schmitt
buffers per hex inverter package, if no better option is
available.

 

[xez]

I don't see any devices that will satisfy the
7VDC supply and at least 3 non-inverting schmitt triggers
per package. I'm sure you could use various comparators
with external resistors, or perhaps some kind of line receiver
with hysteresis, but those will probably be not so much
worth the effort of finding / using as compared to just
using the IC you've identified.

Use a 78L05 regulator, a couple 10uF 12V electrolytic
capacitors, and a couple ceramic 0.1uF capacitors with
one 10uF and one 0.1uF cap paired on the regulator's
input, and another pair on the regulator's output.

Put a 680 ohm resistor from the regulator's output to
ground so you'll meet the minimum load
current requirement for the regulator.

 

[Jdo300]

Hey,

I was looking around and I finally found an IC that can run on 9V. It's a HEF4050. What do you think?

- Jason O

 

[xez]

Hey,

I was looking around and I finally found an IC that can run on 9V. It's a HEF4050. What do you think?

- Jason O

http://www.nxp.com/acrobat/datasheets/HEF4050B_CNV_3.pdf
http://www.nxp.com/#/pip/cb=[type=product,path=50808/53286/29313,final=HEF4050B_CNV_3]|pip=[pip=HEF4050B_CNV_3][0]

It's a non-inverting logic buffer that can run on +9VDC,
yes, but I don't see anywhere that it has built in
hysteresis like a schmitt trigger, so it seems unsuitable.

Perhaps I'm just not reading the same datasheets that
you are, since it may be made by multiple vendors,
and even nxp has other 'related' family datasheets
that I haven't opened... or perhaps I've missed the
mention of the hysteresis though it may be present in
what I've looked at.

 

[xez]

Hmm this bb's software really toasted that second URL
I posted. :(

Anyway, there likely are some interface/buffer/line receiver
products out there that can run on 7V and which have
hysteresis too. Maybe something else made by
NXP, SONY, ON, MAXIM, TI, LTI, ...

 

[berkeman]

I didn't read the whole thread, but how about the MC14584?

I googled: "hex schmidt inverter"

--> http://rocky.digikey.com/WebLib/On-Semi/Web%20Data/MC14584B-D.pdf

 

[berkeman]

Oops, sorry. Why do you want a non-inverting buffer for a ring oscillator? I think I'm in the wrong thread... (happens more often than I like)

 

[xez]

I'm not sure myself why inversion or non-inversion would
matter in his circuit; certainly if he's feeding it with a
square wave, it'd be irrelevant except for the
matter of phase polarity of output relative to the
input signal.

But he said he wanted non-inverting, so I presume he
has his reasons.

 

[Jdo300]

HI All,

I think I had a blonde moment there when I posted that data sheet, the reason I want to use the non-inverting Schmitt buffers is to minimize the number of gates I need to use. For the circuit I posted above to work, I only need three Schmitt buffers, but if I use the inverting ones, then I'll have to use a forth one to get the signal back to the right polarity. The circuit board I'm trying to design is small so I'm trying to minimize the number of chips and traces on the board.

- Jason O

 

[xez]

I understand why it's better to use less parts/gates,
what I meant was that I don't understand why it'd
matter what the output polarity was at any moment
as long as the waveform / frequency / relative phase
to the other FET driver input channels was right.

With a square wave input to the phase shifter and duty
cycle changer it'd eventually produce both outputs,
the only difference inversion would make is an additional
180 degrees from input to output.

What're you doing / studying with your magnetic field
rotator anyway, just for curiosity's sake?

 

[Jdo300]

I'm studying the effects of high velocity rotating magnetic fields on coils. There is this device known as the Steven Mark Toroidal generator which is supposed to produce anomalous effects because of a high speed rotating field so I am studying this to find out for my self what is going on.

- Jason O