CD4541B: VDD limitations

When the datasheet says "For reliable automatic power-on reset, VDD should be greater than 5V", then this implies that at 5 V or lower, the automatic power-on reset is not guaranteed to be reliable.

Use the MASTER RESET input. Alternatively, use a 5 V device from a logic family that is not optimized for higher voltages. There is no P2P replacement for the CD4541B. What features are you actually using?

Thank you, Clemens. I am using this timer as a one-shot to bring HV power supply into controlled hiccup mode when overload conditions occur. Accuracy of timing is not critical as soon as the part oscillates and ready to trigger on a positive logic transition. It looks like 18V part CD4541BC is obsolete now. Is there anything else P2P? My VDD is just 5V, but I cannot change layout. Actually ON Semi MC14541 is 18V part and I think P2P with CD4541BC. Thanks.

Hello Clemens. Thank you for your comments. Tech support from ON Semi confirmed that connecting pin 5 to VDD is a valid solution for MC14541 enabling it to work at VDD<5V. You mentioned about 5V device that is not optimized for higher voltages. What device did you have in mind?

Thank you again and sorry for taking too much of your time for such a small issue.

There are digital timing ICs, one-shots, or counters in the LV-A/HC/AHC/LVC families. What is the exact function you have implemented with the CD4541B?

It is a Digital Timer as it described in the datasheet on page 5. It triggers on the rising edge on pin 6 and produces few seconds long pulse on the output to disable HV power supply after overload conditions. The problem is that this design is in production and we used  CD4541BCM which got obsolete. Then we used ON Semi which worked well until we faced VDD<5V issue.