> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Russell McMahon
> Sent: Thursday, 19 September 2002 4:50 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [EE]: Oscilloscope input amplifier designs sought
> It is likely I will need to design a standard scope-type input stage
> (attenuator and amp) at some time in the not too distant future.
>
> The system will need a bandwidth of 0-200MHz (minimum), nominal input
> impedance of 10Mohm (at some nominal shunt capacitance), and a standard
> 1:2:5 sequence covering gains from 500x to 0.05x.  The output of the
> attenuator and input amp should be a 1V pk signal (preferably
> differential).
>
> The attenuator needs to be electronically controlled (so
> attenuation can be
> selected using 3V3 logic level signals).
> What I would like to do is to collect as many examples of how the "real"
> guys do this as possible.  It is probable that current scope designs will
> all be proprietary black-box implementations but I would think if you were
> to go back far enough there should be examples using discrete
> components for
> which there are full schematics.

Yeap, could provide a scan of a Kenwood CS5156 IIRC scope

It has a rotary switch, but this could be replaced with electronic switchies
:o)


Regards,

Kat.

**********************************************
K.A.Q. Electronics.
Electronic and Software Engineering.
Perth, Western Australia.
Ph +61 (0) 419 923 731
**********************************************

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