How often can I write to the AD5141’s internal EEPROM?

Question How often can I write to the AD5141’s internal EEPROM? Answer It depends on the temperature, typical 1Mcycle @ 25C, minimum 100k cycles.

Maximum Current Density

Question What does maximum current density mean? Answer The maximum current density is the maximum current allowed through the digipot. In potentiometer mode, this isn’t an issue as the resistor is quite high and this limits the current. The specification needs to be taken into account when the part is used in rheostat mode and the resistance can be small, e.g. 500 ohms, maximum voltage in the rheostat terminals is 500 * 6mA = 3V.

Question How different can Vdd and Vlogic be? Answer Vdd is used as a reference signal for ESD protection. No other supply voltage can be higher than VDD so Vlogic maximum voltage is limited to Vdd.

Question How do I calculate the maximum bandwidth? Answer As a first order model, the digiPOT performs as a basic RC filter. The capacitance is added by the W pin capacitance and the resistance should be calculated from the parallel between RAW and RWB. The worst case scenario is at half scale when RAW and RWB are at a maximum. Incrementing or decrementing the code makes the parallel resistor smaller, increasing the BW in the digiPOT.