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logic compatibility of input pins of ad5542a DAC


I have to interface AD5542A dac with serial flash memory. Serial flash is powered at 3.3V and AD5542A is powered at 5V along with its complementary components(2.5v reference generator,reference buffer,output buffer for bipolar dac output) as it was recommended in one of its circuit note.VLOGIC pin of dac is connected to 5V and Vref is 2.5V. All circuitry is working at 50MHz.

I am confused about whether the 3.3Vcmos output of serial flash will be acceptable by AD5542A DIN pin or not. As there is range given for Vlogic (2.7V to 5.5V for 50MHz). Also it is mentioned that for entire range of Vlogic the max and min logic level will remain same.

Basically I want to know that do Dac will accept 3.3V CMOS input at 50MHz or do i have to use some kind of level shifter between them.


  • Hi,

    As long as the output of the flash memory complies with the minimum VINH (2.4V) and maximum VINL  (0.8V) then it should be fine.

    If you have a 3.3V CMOS, then it should comply with the logic levels of the AD5542A. VOH ranges from 2.4V to 3.3V and VOL is 0V to 0.4V.

    Best regards,