tommurphy73
New Member
Hi,
I have and old design product which outputs a frequency up to 100khz. This output frequency is meausred by an external instrument such as a counter or oscilloscope. The output buffer used in this application is a 74lcx244. The issue is the end customers will sometimes sort the outputs to ground and we get some returns with damaged lcx244 devices.
We have a new design which has similar outputs and in order to improve the fault tolerance we decided to go with open drain outputs. We used a 74lcx760 which is the equivalent of the lcx244 with open drain outputs. We put a 3k3 pull up resistor on all the outputs. The issue we are finding with this new device is that the seems to be a lot of noise and ringing on the output.
Anyone have any experience with something similar or can recommend a device which will give us fault tolerant outputs or something like hot swap capability.
Best Regards
Tom
I have and old design product which outputs a frequency up to 100khz. This output frequency is meausred by an external instrument such as a counter or oscilloscope. The output buffer used in this application is a 74lcx244. The issue is the end customers will sometimes sort the outputs to ground and we get some returns with damaged lcx244 devices.
We have a new design which has similar outputs and in order to improve the fault tolerance we decided to go with open drain outputs. We used a 74lcx760 which is the equivalent of the lcx244 with open drain outputs. We put a 3k3 pull up resistor on all the outputs. The issue we are finding with this new device is that the seems to be a lot of noise and ringing on the output.
Anyone have any experience with something similar or can recommend a device which will give us fault tolerant outputs or something like hot swap capability.
Best Regards
Tom