Decoding the tolerance register of AD5259

Question Dear Sirs, using the AD5259 digital potentiometer, I want to make sure, I use the contentsof the tolerance registers correctly if the sign bit is set. How are negative values in the tolerance registers decoded? The first bit ofthe sign-and-integer byte is set. And then? Mask away the sign bit and use theresult as integer? Or is the encoding a 2's complement? Unfortunately, the example in the data sheet handles only the case of apositive tolerance value. Thank you very much for your help. Answer The most significant bit, D7 gives you the polarity of the tolerance and theremaining bits will give you the number. For example,1. MSB=0 and next 7 bits=0011100 would represent +282. MSB=1 and next 7 bits=0011100 would represent -28

AD5259 I2C Device Address

Question I would like to ask you about the I2C device address of AD5259. According to the documentation the complete address is changing by pins AD1 and AD0. In case of other components of the AD525x series the address is 0x58. Does the address really change? Or is it an error in the documentation? Answer The AD5259 has a different core than other components of the AD525x series. The documentation is correct.

AD5259 - "Not Connected Option - third logical stage "1", "0", "NC" ??

Question in the Rev 0. of the AD5259 datasheet there is a table showing the possibility to address 9 devices. On stage is called "NC" meaning I have A0 and A1 and the ligic Levels "1", "0" and "NC" this allows to address 9 parts. Where is this gone? Answer Analog Devices removed the "NC" option moving from datasheet Rev 0 to Rev A. The part includes a current detector in these pins for the floating condition (NC) This circuit somehow is quite sensitive and it could fail under some circumstances. (In fact, some of the new digipots include this circuit but a malfunction is detected at low voltage ( In order to avoid customer problems, these options were deleted from the DS. The circuit is still inside the circuit so if you never experience problems using these address (NC), he/she can continue using it but as these address are not in the DS we cannot assume any responsibility and we are not able to guarantee to function under all circumstances. the normal way is: The A0 and A1 are two state the Logic levels are specified DIGITAL INPUTS AND OUTPUTS Input Logic High VIH 0.7 × VL VL + 0.5 V Input Logic Low VIL ?0.5 0.3 × VL V With A0 and A1 - 4 parts are addressable by logic.