You definitely want to use a level-shifter for reliable operation. I just finished a 14-tube nixie clock with HV5530's driven from an FPGA; I use a MC14504. Some people on this forum have driven HV5530's without a level-shifter; to me saving a few dollars on parts is silly compared to spending hundreds on nixie tubes.
If you are going to use more than 1 HV5530 (necessary for a 6-digit clock), then be careful about cascading the HV5530's. The datasheet info is incomplete, so it's possible to have a timing-violation if you connect the serial-out to the serial-in of the next HV5530 *and share the same clock signal*. Better to use 2 separate serial-data-in signals. In my case, I had to cascade two HV5530's because my ribbon-cable didn't have enough signals (a long story), but I used 2 different clocks. The MC14504 has 6 level-shifters, so you can drive all of the necessary control signals for 2 HV5530's (clk, data_in, le, bl, pol). It's very easy to make a mistake on the 'bl' and 'pol' control-signals, so if you decide to tie them off, make sure you use resistors so you can pull high or low on the PC board. I drive them from my FPGA. ----------------------------------------- FYI - The ribbon cable in my clock is over 3 feet long, and in a noisy electrical environment, it was absolutely necessary to terminate the clock-lines to control reflections. Even though the cable's impedance is roughly 120 ohms, I got good results (from simulations and bench measurements) terminating at 330 ohms. Though terminating at 120 ohms is best from transmission-line theory, it puts a lot more loading on the driver. As long as the reflections are well-below the threshold-voltage of the MC14504, they are harmless. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/fa9e6b84-e744-4c80-b283-77b46c94a0fc%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
