Are you driving segmented tubes (like the 7971) ? If so, I would advise 
against the HV-series drivers because you will need several different 
segment-currents.

If it's a traditional 10-cathode nixie, where each numeral uses the same 
current, the HV devices work great. There's a variety of opinions about 
using drivers rated below the anode supply voltage. The legacy 74141, which 
is rated around 45V, has been used for nixies for years and it's 
suitability relies on the voltage-drop across a nixie.  While it's probably 
OK for bipolar (NPN) output drivers as long as the current is limited, it 
*definitely* is *not* OK to exceed ratings for MOS devices because it will 
cause destructive breakdown.

I looked at the HV3418 datasheet, and I dont think it will suffice for 
nixies because the spec value of the *low* output voltage at 5mA  load is 
25V. If you are running from a +180V supply, the tube will 'see' less than 
155V because of the voltage-drop on the anode resistor. The ability to run 
at +5V on the logic side may sound desirable, but the other specs in my 
opinion make this device unsuitable.

I cant say enough good things about the HV5530. I have a 14-tube clock w/ 
IN-18's that has been running for over a year now with zero issues. I used 
a level-shifter to drive the HV5530 inputs to 12V from my FPGA, which has 
3.3V I/O's.  Instead of an anode resistor to set the segment current, I use 
a PMOS device to generate constant current.




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