K155ID1 power dissipation

I build my own nixie clock with four digits (IN-14, 10k anode-resistor) with a seperate K155ID1-IC for each digit (so no multiplexing). Also, I am only using the 0-9 range, so every tube has one digit lit up the whole time. However, the ICs start to get a little bit warm, while I can still barely touch them without getting burnt. I measured an average current of 45mA per IC, which would lead to a power dissipation of ~225mW per IC. This seems too high to me, as the datasheet of the "equivalent" 74141 IC describes a typical power dissipation of only 55mW which is only a quarter of my power dissipation. So basically my question is if you have an idea what mistake I did, or if one of you also uses the K155ID1 and could provide me with information on their power dissipation.

Kind regards :)

Edit: I have also tried using an 20k anode resistor, power dissipation of the IC does not change

• From datasheet ИН-14 anode current should be in the range 2,5...3 mA (2 mA at pulsed 50 Hz voltage). Discharge voltage is 120...170 V and supply voltage should be >200 V. Looks like overload of both IC and indicator. Commented Aug 11, 2022 at 11:23
• @Vladimir The power supply is a 170V-step-up-converter. As I understand the datasheet, the supply (firing) voltage is 170V, with an absolute maximum of 200V. The maintaining voltage is around 145V. As mentionend in the comment below, the voltage on the resitors is about 25-30V, thus resulting in a current of 2.5-3mA. Commented Aug 11, 2022 at 12:36
• If it turns out that the K155ID1 simply has a higher power dissipation, you can get heatsinks for 16-pin DIP ICs. Commented Aug 11, 2022 at 13:49
• ICs could be defective, it is unknown, from where seller got them, may be from waste bin. You can try to power it on with unconnected inputs and outputs. If they still draw much current, this is defect. You can still use it in non-critical devices. As Andrew Morton wrote, heatsink will help, i saw TTL ICs with heatsinks in some factory devices, but heating was caused by high working frequency and load. Commented Aug 11, 2022 at 13:55
• @Vladimir as mentioned in my comment under the other answer, the current with only the supplies wired up is about 17mA. I have uploaded the schematic to my circuit: imgur.com/a/ukUC2VE Commented Aug 12, 2022 at 14:00