DS2423 Counter Spec

[stevendt]

Hi,

does anyone know the maximum frequency that a DS2423 could reliably accumulate counts for please ?

Also, at what value does the counter "roll-over" ?

regards
Dave

 

[sda]

Hi,

does anyone know the maximum frequency that a DS2423 could reliably accumulate counts for please ?

Also, at what value does the counter "roll-over" ?

regards
Dave

I know! I know!

You could too if you read the spec sheet.

OK, the first question is a little tough.

There's a footnote that says:
Each low-going edge on a counter input resets the channel’s debounce timer. The debounce time
starts as the input voltage rises beyond the trip point. In order for the next pulse to be counted the
debounce time must have expired.

The trip point is 1/2vbat.

The input needs a minimum 1us pulse.

The debounce time varies from 170us to 460us, avg 290us.

Figure it as 500us to allow for a longer pulse and a margin for error, and 500 is a nice number.
1000000 / 500 = 2000 times per second.
At least I think that's right.

The second question is easy.
Its a 32 bit counter. Doesn't say anything about a sign bit, so I'd assume its a full 32 bits.
2^32 - 1, or about 4.3 billion, give or take a few million.

howzat?