Cathode Driver - Multiplexed Nixies

Thread Starter

TheMobius40

Joined Sep 13, 2018
28
Hello,

I am trying to find the best way to drive the cathodes of multiplexed nixie tubes in as small a form factor as possible. The best way I have found is to use an IC like the Micrel MIC5841, though I'm not sure how to set this up. I am familiar with how the shift register portion works.

Clock, serial data in, and serial data out are pretty obvious.
Output enable seems self explanatory, but it is active low. Does this mean that if it is not driven, or grounded, it will be enabled?
I am not clear on what strobe does. I am not sure what the functions of Vee or K are either.

Using discrete transistors is also an option, though this method would require many more connections to the MCU than the IC.
Thank you for your time.

FuncDia.PNG PinConfig.PNG
Functional Diagram and Pin Configuration - MIC5841​
 

danadak

Joined Mar 10, 2018
4,057
The strobe basically transfer the data into the latches, from the SR,
when the strobe is high. And if OE is low that flows to the output
pins.

Vee is tied to all the emitters of the output transistors, and when the transistor
is on pulls the nixie cathode negative which turns on the nixie segment.

Regards, Dana.
 
Last edited:

ebp

Joined Feb 8, 2018
2,332
The voltage rating of that part is not likely adequate for Nixies.

K is used for clamping inductive loads. It can be left open for other types of loads.
 

Thread Starter

TheMobius40

Joined Sep 13, 2018
28
Alright, it sounds like the best solution would be to use a regular shift register with external high voltage transistors like the MPSA42.
 
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