Note: The operation of this circuit depends on the breakdown characteristics of the 2N2369 transistor used.
Please refer to the Application notes provided.
I had no problems with the boards I constructed but I have had reports of the circuit not working. The 2N2369 transistors appears to be no longer available. I have no experience with using the circuit with 2N2369A or BSX20 devices. Ihave a report that is does not work with these devices likely due to insufficient voltage to breakdown.
This module produces a pulse with a very fast rise time.
Its main use is for testing oscilloscope rise-time and hence estimating bandwidth.
For convenience the module is powered from a micro-usb socket.
Most current oscilloscopes have a USB host socket that can provide the power needed.
Connection to the oscilloscope will require a BNC-to-BNC adapter.
A length of 50ohm coax should be used to extend the pulse so that rise-time may be measured.
References:
A Seven-Nanosecond Comparator for Single Supply Operation, Linear Technology’s Application Note 72, May 1998
High Speed Amplifier Techniques, Linear Technology’s Application Note 47, August 1991
This is an Altium designer project.
Refer to the PDFs in the Project Outputs directory for layout and BOM PDF Documentation
PCBs may be ordered from OSH park
