TTL Voltages

ajras

Hi all,

I'm curious to know if there is a way to "recalibrate" the TTL output voltages from Artiq. Currently the low voltage is 1.22V and the high voltage is 3.9V (as measured by a multimeter). We have a fast, broadband switch that needs more precise values though: 0-0.8 for low and 1.2-3.3 for high. Is the only solution to use a voltage divider? Or can we somehow adjust the ttl voltages in software?

Thanks,
AJ

sb10q

1.22V low voltage is surprising. Where did you buy that TTL card? Which channels are affected? Where exactly did you connect the multimeter?

jbqubit

The voltages are not software adjustable. Look at the schematics.

https://github.com/sinara-hw/DIO_BNC/releases/tag/V1.4

ajras

I'm sorry. I recorded the voltage incorrectly. The low voltage is 0.122. However, the high voltage 3.9 is still out of spec for the switch (<3.6).