282: Difference between revisions

80 bytes added ,  12 December 2010
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probes to be used with instruments that have 50-ohm inputs.  It is a unity-gain buffer with
probes to be used with instruments that have 50-ohm inputs.  It is a unity-gain buffer with
an input impedance of 1 megohm in parallel with 16.5 picofarads and a low output impedance.  
an input impedance of 1 megohm in parallel with 16.5 picofarads and a low output impedance.  
The high-impedance input stage is a dual-JFET where one transistor operates as a source-follower
The high-impedance input stage is a dual-JFET where transistor A operates as a source-follower
and the other transistor operates as a current source biased with Vgs=0.
and transistor B operates as a current source biased with Vgs=0, maintaining a constant
current through transistor A, independent of input signal voltage.
The risetime is 3ns when driven from a 25-ohm source.
The risetime is 3ns when driven from a 25-ohm source.


* [http://w140.com/tek_282.pdf Tektronix 282 Manual (PDF)]
* [http://w140.com/tek_282.pdf Tektronix 282 Manual (PDF)]