[sdiy] The sound of various Op-Amps

[James Patchell]

GBW and Slew Rate are indeed two different things.  Slew Rate is actually a 
non-linear property, GBW product is a linear property.  Quite often there 
is a one to one correspondence.  For example, the uA741 has a GBW product 
of 1MHz (Gain = 1) and a slew rate of .5V/uS...another opamp I used from 
Harris many years ago also had a GBW product of 1MHz, but a slew rate of 
20V/uS.

Also, if you are using the LM301, you could choose to apply feed forward 
compensation, which would bypass the lateral PNP transistor in 
amplifier.  This would increase your GBW by a factor of 10, and the slew 
rate by about 20, if I remember correctly (seems lie I remember getting 
10MHz GBW and 10V/uS Slewrate when this was done).


At 12:55 PM 9/21/2003 +0200, Ingo Debus wrote:

>Am Sonntag, 21.09.03 um 06:09 Uhr schrieb harrybissell:
>
>>Another place that 'fast' slew rate becomes important is when really high 
>>gain
>>is expected from
>>one stage.  Because of the gain / bandwidth product of most of the plebian
>>opamps I use...
>Aren't slew rate and gain-bw-product two different things? Sure, for a 
>'fast' opamp both are high, but if you're looking for high 
>gain-bw-product, you're not looking for a fast slew rate in the first place.
>
>Ingo

         -Jim
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