lm324 op amp

[SioL]

Joerg wrote...

Not that bad... For example, Vishay BAT82S (44348 in stock),
SD101A (16922 in stock) are both $0.03, qty 1k at Newark, $0.05
in singles, and the LS101C smd part a bit more, $0.04 for 1k...

BAV70, dual SMD schottky.

SioL

 

[Joerg]

Hi Winfield,

Not that bad... For example, Vishay BAT82S (44348 in stock),
SD101A (16922 in stock) are both $0.03, qty 1k at Newark, $0.05
in singles, and the LS101C smd part a bit more, $0.04 for 1k...

That is a good price for a Schottky diode. Wish they were in SMT though.
This could actually beat the transistor which can be had under 2 cents
but it needs a resistor for base current and that adds a penny back in.

The BAT54S is SMT but over 10 cents. Well, at least you get two in one
SOT23 pack for that. They are nice for building mixers.

Regards, Joerg

 

[Spehro Pefhany]

Joerg wrote...

Not that bad... For example, Vishay BAT82S (44348 in stock),
SD101A (16922 in stock) are both $0.03, qty 1k at Newark, $0.05
in singles, and the LS101C smd part a bit more, $0.04 for 1k...

Or the very available BAT54 (SOT-23) 200mA/30V $0.03 in 250 at Mouser
or Allied.


Best regards,
Spehro Pefhany

 

[Tim Wescott]

Ha! That was an enjoyable little read. I especially liked

The figure was drawn with thermionic tubes to avoid any suggestion of
partiality in favour of any particular semiconductor device. Since
thermionic devices at present are not generally available in IC chip form

I'd never seen that section of their website, I gotta read the rest
now

Tim.

"Not _generally_ available". I didn't even notice that -- I just
searched down to the section on phase inversion to make sure that it was
what you were looking for. Now _I_ gotta read it...

 

[Joerg]

Hi SioL,

BAV70, dual SMD schottky.

These are not Schottky but regular diodes. They are great diodes and I
just used them in a design last week. Basically the same as BAV99 except
that the BAV70 is common cathode.

Regards, Joerg

 

[M.Randelzhofer]

Hi Winfield,

That is a good price for a Schottky diode. Wish they were in SMT though.
This could actually beat the transistor which can be had under 2 cents
but it needs a resistor for base current and that adds a penny back in.

The BAT54S is SMT but over 10 cents. Well, at least you get two in one
SOT23 pack for that. They are nice for building mixers.

Regards, Joerg

The BAT54xW in a SOT323 / SC70 case seems to be much cheaper. A 3000 reel
costs me 2.5 euros per 100 - the SOT23 was 8.5 euros.

MIKE

 

[John Larkin]

Hi Winfield,

That is a good price for a Schottky diode. Wish they were in SMT though.
This could actually beat the transistor which can be had under 2 cents
but it needs a resistor for base current and that adds a penny back in.

The BAT54S is SMT but over 10 cents. Well, at least you get two in one
SOT23 pack for that. They are nice for building mixers.

Regards, Joerg

But be careful: a small-signal schottky may not conduct hard enough to
protect an LM324!

John

 

[Joerg]

Hi John,

But be careful: a small-signal schottky may not conduct hard enough to
protect an LM324!

The OP was only concerned about the input where you could limit the max
current. But you have a point here since the LM324 abs max is spec'd at
300mV. Less than a Schottky would offer. So I'd still favor either the
reversed transistor or a pre-biased silicon diode.

Regards, Joerg

 

[Joerg]

Hello Mike,

The BAT54xW in a SOT323 / SC70 case seems to be much cheaper. A 3000 reel
costs me 2.5 euros per 100 - the SOT23 was 8.5 euros.

Thanks! That sounds much better even though a Euro is now over $1.20.
But ON Semi makes these, too, so we have a domestic source. Hey, we even
can get Spaten Oktoberfest Beer over here

Regards, Joerg

 

[N. Thornton]

And nothing over a dime or two, please. ;-)


Best regards,
Spehro Pefhany

and thats the beauty of the 324... any time it can handle the app, its a winner.

NT

 

[Daniel Haude]

On 10 Oct 2004 03:17:51 -0700,

I'd never seen that section of their website, I gotta read the rest
now

Same here; I think it's fantastic!

--Daniel

 

[Jim Thompson]

Has anyone found this problem,

When a negative voltage is connected to the input of this op amp the output
will go positive, and the other outputs will go slightly positive.

Do you know what causes this?

Thanks

Duh!?!?

...Jim Thompson