CharlieO21 Posted December 12, 2017 Share Posted December 12, 2017 Hello, I'm using the pattern generator with the output type set to open drain when the output is Z, measuring the output impedance I read almost 5K Ohm, What could be the problem? Link to comment Share on other sites More sharing options...
JColvin Posted December 12, 2017 Share Posted December 12, 2017 Hi @CharlieO21, Could you attach a picture of your physical set up on how you measuring the impedance? When I measured the output impedance of a pin on the pattern generator set to constant with an output Z, I measured. Here is a picture of my setup. Thanks, JColvin Link to comment Share on other sites More sharing options...
attila Posted December 13, 2017 Share Posted December 13, 2017 Hi @CharlieO21 The digital IOs have series PTCs and protection diodes to ground and internal 3.3V. https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual#digital_io Having the DMM COM connected to AD DIO and DMM Ohm to AD ground, the DMM will measure the "forward resistance" of the PTC+diode. Link to comment Share on other sites More sharing options...
CharlieO21 Posted December 13, 2017 Author Share Posted December 13, 2017 20 hours ago, JColvin said: Hi @CharlieO21, Could you attach a picture of your physical set up on how you measuring the impedance? When I measured the output impedance of a pin on the pattern generator set to constant with an output Z, I measured. Here is a picture of my setup. Thanks, JColvin I'm using the same measurement. 9 hours ago, attila said: Hi @CharlieO21 The digital IOs have series PTCs and protection diodes to ground and internal 3.3V. https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual#digital_io Having the DMM COM connected to AD DIO and DMM Ohm to AD ground, the DMM will measure the "forward resistance" of the PTC+diode. I think you are right, that "forward resistance" make a voltage divider on my setup and my signal never go up Link to comment Share on other sites More sharing options...
Question
CharlieO21
Hello, I'm using the pattern generator with the output type set to open drain when the output is Z, measuring the output impedance I read almost 5K Ohm, What could be the problem?
Link to comment
Share on other sites
3 answers to this question
Recommended Posts
Archived
This topic is now archived and is closed to further replies.