Single gate version of the HEF4093 ?

DaVaDa · Aug 4, 2009

Does anybody know about a version of the HEF4093 with one gate only?

I have noticed that the Logic Diagram for one of gates on the HEF4093 contains two op-amps, and I have tried to find something similar using the keywords "Single 2-input NAND Schmitt trigger". But without success until now.

I have an existing square wave oscillator with the "4093", and the purpose is simply to make a new and more small PCB. (With tiny SMD components of course).

ericgibbs · Aug 4, 2009

DaVaDa said:
Does anybody know about a version of the HEF4093 with one gate only?

I have noticed that the Logic Diagram for one of gates on the HEF4093 contains two op-amps, and I have tried to find something similar using the keywords "Single 2-input NAND Schmitt trigger". But without success until now.

I have an existing square wave oscillator with the "4093", and the purpose is simply to make a new and more small PCB. (With tiny SMD components of course).

hi,

Is a SMT 555 timer ic an option.?

NATIONAL SEMICONDUCTOR|LM555CM|TIMER, SMD, SOIC8, 555 | Farnell United Kingdom

DaVaDa · Aug 4, 2009

Yes, it is an option. And I have allready tried this. It seems to work with the required frequency after trimming the value of resistors and capacitors.

But what frustrates me is another attempt using the 74LVC1G00GW. It is a nice little SOT353-1 called "Single 2-input NAND gate" and the description says "Schmitt trigger action at all inputs....". So my first thought was to replace the 4093 with this one. But the oscillation does not seem to happen. At least not with the same values as with the 4093. (The 4093 oscillated with 4.5kHz with 4.7nF and 81K).

There seems to b a difference in the logic diagrams for this chip compared with the 4093. The 4093 has two opamps, while the 74LVC1G00GW only has one opamp.
Any opinion about this problem?

DaVaDa · Aug 14, 2009

Found something anyway.....

Hi

The logic diagramme for the M74VHC1G132 is not fully identical with the HEF4093 because it has one opamp only after the gate, where HEF4093 has two opamps.

In spite of this the M74VHC1G132DTT1G seems to work just like one of the HEF4093 gate. Don't really know why, but it works!

....He, he

)

audioguru · Aug 16, 2009

The 4093 and the 74HC132 do not have any opamps.
They have non-inverting schmitt trigger inputs or inverting ones.
They have NAND gates or NOR gates.
They have one or two logic inverters.

They do the same function but the Schmitt trigger threshold voltages are different because they are from different logic families.

DaVaDa · Aug 17, 2009

Thank you.

It seems to be my misunderstanding about the meaning of the triangle symbol....

Thanks a lot.

audioguru · Aug 17, 2009

An opamp has 30 to 50 transistors, resistors and diodes.
A Cmos logic inverter has only one P-channel Mosfet and one N-channel Mosfet.

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Single gate version of the HEF4093 ?

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