CD4541B - Auto Reset disable won't work

Don Ausherman

Other Parts Discussed in Thread: CD4541B

As I understand it, when the AR pin of the CD4541B (pin 5) is tied high, it is supposed to keep the counters from resetting at power up and going through a timing cycle. No matter what I've tried, the part always goes through a timing cycle at power up. This part has been around for at least 25 years, so I have to believe I'm doing something wrong or interpreting the data sheet incorrectly. Does anyone have any suggestions?

over 13 years ago

0 Chris Cockrill over 13 years ago

TI__Mastermind 46480 points

Pin 5 should be high and pin 6 should be low. All the state pins should be set to something not floating.

0 Avi Chami1 over 13 years ago in reply to Chris Cockrill

Mastermind 7395 points

I am sorry if I don't understand, but did you expect the counter to retain its value during a power cycle? If that is what you expected, that cannot be done, the device is volatile and will reset upon power on. The function of the auto reset enable or disable is wether to start counting automatically (or not) after a power cycle.

0 Don Ausherman over 13 years ago in reply to Avi Chami1

Prodigy 185 points

I realize it can't remember anything through a power down. I want it to NOT start counting at power up. I have all the pins tied either high or low.

0 Michael WS over 13 years ago in reply to Don Ausherman

Prodigy 135 points

Dear Don Ausherman, I have same issue like you. I don't want it to START COUNTING in the power up IC. I mean this IC will start counting every time when power up.

How to set CD4541B?

1) Power start up ----- Should not be start counting until "MR" pin 6 puls trigger (pin5 Lo or Hi still same).

2) Start conting during Power up is normal function?

3) If start counting is normal function, pleaase update in spec sheet as well.

Thanks,

Michael WS

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CD4541B - Auto Reset disable won't work