Do want it as cheap as possible ?  How easy do you want to make the adjustm=
ent ?  Is the adjustment once and forget it ?  How many will you be making =
?  What is the load ?

> On Jul 4, 2013, at 12:32 PM, Yigit Turgut wrote:
>=20
> I don't need adjustable rise/fall times, I would prefer as fast as it get=
s.
> Load has some capacitance it's a LED.
>=20
>=20
> On Thu, Jul 4, 2013 at 8:58 PM, Sean Breheny <shb7@cornell.edu> wrote:
>=20
>> Do you need the rise and fall times to be adjustable or just shorter
>> (faster) than some value? If the latter, I would recommend looking at lo=
gic
>> gates to "square up" your signal. 74AC or 74AHC series should easily be
>> able to deliver <2ns rise/fall times. You may want to use schmitt trigge=
r
>> versions, too. There are probably even more modern ones that can do even
>> better. What is your load for this signal? Any capacitance in the load w=
ill
>> make this more challenging and may require paralleling of several gates =
to
>> have sufficient drive.
>>=20
>>=20
>> On Thu, Jul 4, 2013 at 1:41 PM, Yigit Turgut <y.turgut@gmail.com> wrote:
>>=20
>>> Hi collective brain,
>>>=20
>>> I want to generate a pulse/square signal with a few nanoseconds of
>>> rise/fall times. I did this with various PIC's and with FPGA's and I go=
t
>>> around 2ns of rise/fall times which is good but I need to make it simpl=
er
>>> (cheaper).
>>>=20
>>> Now I am trying to implement the same with completely analog components=
 ;
>>>=20
>>> width ; adjustable between 2ns-10ns
>>> frequency ; adjustable between 1Hz-200Hz
>>> amplitude ; adjustable between 5V-12V
>>>=20
>>> I know there are some defacto ways to do this but I feel rusty on the
>>> analog side and would appreciate the guidance of analog experts here. I
>>> know you are out there, don't hide!
>>>=20
>>> Yigit
>>> --
>>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
>>> View/change your membership options at
>>> http://mailman.mit.edu/mailman/listinfo/piclist
>>>=20
>> --
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>> View/change your membership options at
>> http://mailman.mit.edu/mailman/listinfo/piclist
>>=20
> --=20
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>=20
>=20
--=20
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