Difference between revisions of "S-53"

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The Tektronix S-53 Trigger Recognizer is essentially the entire trigger circuit of an oscilloscope.  It
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The Tektronix S-53 ''''Trigger Recognizer''' is essentially the entire trigger circuit of an oscilloscope.  It
is rated to 1GHz and has a BNC input with 50-ohm impedance.  It uses tunnel diode triggering with an
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is rated to 1 GHz and has a BNC input with 50 Ω impedance.  It uses tunnel diode triggering with an
amplifier before the tunnel diode.  The input signal to trigger out jitter is rated at 15ps or less.
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amplifier before the tunnel diode.  The input signal to trigger out jitter is rated at 15 ps or less.
The trigger-out signal is 1V into 50 ohms, with 600mV/ns slew rate.
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The trigger-out signal is 1 V into 50 Ω with 600 mV/ns slew rate.
  
 
The signal first passes through a compensated NPN differential amplifier, Q10 and Q12, which provides
 
The signal first passes through a compensated NPN differential amplifier, Q10 and Q12, which provides
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File:Tek s53 right2.jpg
 
File:Tek s53 right2.jpg
 
File:Tek s53 rear.jpg
 
File:Tek s53 rear.jpg
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</gallery>
  
  
</gallery>
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[[Category:7000 and 3S series sampling heads]]

Revision as of 05:55, 18 May 2014

The Tektronix S-53 'Trigger Recognizer is essentially the entire trigger circuit of an oscilloscope. It is rated to 1 GHz and has a BNC input with 50 Ω impedance. It uses tunnel diode triggering with an amplifier before the tunnel diode. The input signal to trigger out jitter is rated at 15 ps or less. The trigger-out signal is 1 V into 50 Ω with 600 mV/ns slew rate.

The signal first passes through a compensated NPN differential amplifier, Q10 and Q12, which provides an adjustable trigger offset voltage and trigger polarity selection. Switching diodes CR6 and CR8 are used for selecting the trigger polarity. The differential amplifier (i.e., phase splitter) generates both phases, inverted and noninverted. Depending on the position of the trigger polarity switch, one or the other of the phases is shunted by 200 ohm resistor. The two signals are buffered by common-base amplifiers Q20 and Q22, whose collector currents are summed. R25 sets up a bias current on trigger tunnel diode CR25. The extra current from Q20 or Q22 pushes CR25 over its peak current, and it switches to the high voltage state.