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CA 3082 alternatives

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Roger Dewhurst

Jan 1, 1970
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Are there any alternatives for the transistor array chip CA 3082 which is
now obsolete.

R
 
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Rich Grise

Jan 1, 1970
0
Are there any alternatives for the transistor array chip CA 3082 which is
now obsolete.
According to the data sheet, it looks like something like the ULN2003
could be pressed into service - I haven't bothered to check the pinouts,
but if all you need is the functionality, that's the one I'd go for.

Cheers!
Rich
 
R

Roger Dewhurst

Jan 1, 1970
0
Rich Grise said:
According to the data sheet, it looks like something like the ULN2003
could be pressed into service - I haven't bothered to check the pinouts,
but if all you need is the functionality, that's the one I'd go for.

Cheers!
Rich

Thanks. Pin outs do not matter. I will grab the data sheet.

R
 
R

Rich Grise

Jan 1, 1970
0
Thanks. Pin outs do not matter. I will grab the data sheet.

But be careful! An ohnosecond after I posted this, I looked at the data
sheet again, and the 3081 has the emitters in common, but the 3082 has
the collectors in common - the ULN2003 has the emitters in common, so
I might have given you a bum steer. Sorry if I've misled you.

Good Luck!
Rich
 
R

Roger Dewhurst

Jan 1, 1970
0
Rich Grise said:
But be careful! An ohnosecond after I posted this, I looked at the data
sheet again, and the 3081 has the emitters in common, but the 3082 has
the collectors in common - the ULN2003 has the emitters in common, so
I might have given you a bum steer. Sorry if I've misled you.

Good Luck!
Rich

They are only to interface between 4026 chips and 7 element LEDs. I thought
that perhaps the ULN2003 is a little over the top for that job. I have
found other ones but they are all Darlingtons. I could use single
transitors but that mean much more wiring and soldering.

R
 
G

Gerhard

Jan 1, 1970
0
Roger Dewhurst said:
They are only to interface between 4026 chips and 7 element LEDs. I
thought
that perhaps the ULN2003 is a little over the top for that job. I have
found other ones but they are all Darlingtons. I could use single
transitors but that mean much more wiring and soldering.

R

Try digital transistors, also known as biased transistors provided your
max. continous current is less than 100mA. They save you mounting the
resistors
and come in TO92, SOT323 and SC75.

see On Semiconductor MUN5211T1 as example of bias resistor transistors.
On www.onsemiconductor.com Go to 'Bipolar Transistors > Bias Resistor
Transistors'
on the main page.

See Fairchild FJN3114R as example of biased transistors.
On www.fairchildsemi.com go to 'small signal transistor' tab on main page
and then select 'digital' tab in the left hand column under the 'Function'
section.

They come in NPN and PNP nominal 50V 100mA with different bias resistors.
Some Fairchild and OnSemi devices are available from www.mouser.com in
small quanteties.

You can also try low threshold small signal FETs but they tend to be more
expensive.


Gerhard van den Berg
CSIR
 
G

Gerhard

Jan 1, 1970
0
Roger Dewhurst said:
They are only to interface between 4026 chips and 7 element LEDs. I
thought
that perhaps the ULN2003 is a little over the top for that job. I have
found other ones but they are all Darlingtons. I could use single
transitors but that mean much more wiring and soldering.

R

Try digital transistors, also known as biased transistors provided your
max. current is less than 100mA. They save you mounting the resistors.
They come in TO92, SOT323 and SC75.

See On Semiconductor MUN5211T1 as example of bais resistor transistors.
On www.onsemiconductor.com Go to Bipolar Transistors > Bias Resistor
Transistors
on the main page.

also see Fairchild FJN3114R as exampel of biased transistors.
On www.fairchildsemi.com go to 'small signal transistor' tab on main page
and then select 'digital' tab in the left hand column under the 'Function'
section.

They come in NPN and PNP nominal 50V 100mA with different bias resistors
Some of the range are available from www.mouser.com in small quanteties.

You can also try low threshold small signal FETs, but they tend to be more
expensive.


Gerhard van den Berg
CSIR
 
R

Roger Dewhurst

Jan 1, 1970
0
Gerhard said:
I asked the wrong question. I should have asked "What is the best way of
driving a four digit, seven element LED display, in milliseconds, from the
outputs of four 4026 CMOS chips?"

Roger
 
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