Daisy Chaining AD532x parts

Question How do I daisy chain multiple AD5325 devices together? Answer To daisy chain multiple AD523X devices, simply connect SDO to SDI and run a common SCLK and /CS to all devices. To program many AD523X devices in a "daisy chain" configuration. Pull the /CS lines low on all chips. Send the data into the CLK and SDI pins of the first AD523X in the chain. The data format should be data for the last potentiometer in the chain sent first. Once data for all converters in the chain is sent, a positive edge on /CS will load data into all potentiometers simultaneously. You must always write the same word length to the chain of devices. For example when two AD5232s are daisy chained together, you must always write 32 bits, for 4 devices, you must write 64 bits. If you only want to update the contents of a single device, simply write a NOP to the device locations you do not wish to update. Also ensure that the recommended 2k pullup resistor is used on SDO!

AD5235: RFI sensitive environment

Question We use the AD5235s in a very sensitive RFI environment. On system power-on, howis the scratchpad register refreshed with the EEMEM value? Is it clocked in? Answer At power up, the internal oscillator turns on, waits for power up time ofinternal NVM and then it loads NVM value to internal register.So yes, the clock is used to load the NVM value to scratchpad register.Internal Frequency is 1MHz, and it switches off after registers are loaded.

Question The problem is very simple. The seriel programming Signals are provided by the FPGA, but the AD5235 doesnA?t store the value. I think I am not providing all needed signals or timings. Is it possible to get an explanation how to connect the chip, focus on CS, WP and PR? Answer If you are not using WR and PR, then you should tie them high. The /PR pin is a digital input, applying a logic low, will refresh the contents of the scatch pad memory (RDAC register) with the current contents of the EEMEM memory. At power-on, the default value of the scatch pad memory is the value previously saved in the EEMEM, therefore, to answer your question, on power-on the value of the scatch pad will be loaded with the previously loaded contents of EEMEM, without applying a logic low to /PR, you don't need an RC circuit connected to /PR to ensure that the scatch pad is refreshed, as this is automatic on power-up. To write to the part, you need only to connect CS, SDI and SCLK.

Question I am using the AD5235 Digital Potentiometer in my Final Year Project at University. I am going to try and daisy chain several of the Potentiometers together, but I am unsure where to begin. Do you have any technical notes on Daisy-chaining your digital potentiometers? Answer To daisy chain multiple AD523X devices, simply connect SDO to SDI and run a common SCLK and /CS to all devices. To program many AD5235s in a "daisy chain" configuration. Pull the /CS lines low on all chips. Send the data into the CLK and SDI pins of the first AD523X in the chain. The data format should be data for the last potentiometer in the chain sent first. Once data for all converters in the chain is sent, a positive edge on /CS will load data into all potentiometers simultaneously. You must always write the same word length to the chain of devices. For example when two AD5235s are daisy chained together, you must always write 32 bits, for 4 devices, you must write 64 bits. If you only want to update the contents of a single device, simply write a NOP to the device locations you do not wish to update. Also ensure that the recommended 2k pullup resistor is used on SDO.