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Information for clarity in regards to AD5272's 50TP/OTP

Question asked by aries1470 on Aug 19, 2015
Latest reply on Oct 27, 2017 by koushik.kops

Hi,

I would like some clarification for this part.

I will be using an arduino uno initially to communicate with it, and what I would like to clarify with the device is the following statement from page 21:

"...contain an array of 50-TP programmable memory registers,... ...It is possible to read back the contents of any of the 50-TP memory registers through the I2C interface by using Command 5 in Table 12."

I do not yet have teh piece, as I would like to be certain before starting with it, for the following:

 

1. Does this mean that we can program up to 50 different permanent values?

If yes, we can read this value back from the device and then send it as an active value, or can we tell it to "activate" a certain value

As an example:

Read value from position 3 and use that.

Does that mean:

Read value from position 3 in the 50 TP registery

Write value

Is that correct, or is there a shorter / quicker way.

2. In reference to the previous question, my main concern is: from P1 of the PDF:

"The AD5272/AD5274 device wiper settings are controllable through the I2C-compatible digital interface. Unlimited

adjustments are allowed before programming the resistance value into the 50-TP memory. The AD5272/AD5274 do not require any external voltage supply to facilitate fuse blow and there are 50 opportunities for permanent programming. During 50-TP activation, a permanent blow fuse command freezes the wiper position (analogous to placing epoxy on a mechanical trimmer)."

The way I originally interpret that statement is equivalant to 50 times non-volatile memory, and on the last turn off of power for the 50th time, that it will be fixed at that location, and then need to move the wiper...

3. Is there a sample program available of how it would look like, simalar to here:

https://ez.analog.com/message/210109#210109

 

As an example, I will be using 2 parts, 1 will be a 20K and the other a 100K part,

can it include the following please, if possible:

 

Put wiper to 5K : For the 20K part

Place value in position 3 of 50TP and save it to the 20K part.

Read value in position 7 from 50TP :For the 100K part

 

I hope I am not asking for to much. I am aware that altering PIN 10, will alter the address, so one can be tied to GRN the other to VDD.

 

Thank you in advance.

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