EEPROM selection for 192KHz fs ADAU1701

SigmaDSP & SigmaStudio MCastany Oct 4, 2013 00:00 2 replies Original on forum ↗

MCastany Question

Oct 4, 2013 00:00

Hello,

I'm searching an EEPROM for self-boot the ADAU1701 working with a sampling frequency of 192KHz.

The datasheet specifies that the ADAU1701 generates SCL at 8 x fs, so for a 192KHz samplig freq, SCL runs at 1.536MHz. I've been searching a 8.5KB EEPROM taht could reach this frequency, but the only ones I found can run at a maximum of 1MHz.

Does anyone had this same problem and found an EEPROM for running at 192KHz?

Thank you!!

Audio Signal Processors

eeprom

SigmaDSP Audio Processors

adau1701

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ADIApproved Reply

Oct 4, 2013 00:00

Hello,

This isn't explained very well in the datasheet, but "fS" actually refers to the base sample rate of the system. You have a register control that allows you to operate in double-rate or quadruple-rate modes, but all this really does is force the program to execute its loop twice as fast or four times as fast, respectively. In other words, changing the sample rate to double (96 kHz) or quadruple (192 kHz) mode doesn't actually change the frequency of the core clocks within the chip.

So, use 48 kHz * 8 = 384 kHz for the EEPROM SCL frequency, even though your system is running at a 192 kHz sample rate.

Thanks,

Brett

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MCastany Reply

Oct 27, 2013 00:00

The EVAL-ADAU1701MINIZ uses a 256Kb memory, but I'll use the ATMEL AT24C64B, 64Kb 400KHz, and 64Kb as the AN-923 recommends on page 1, hardware setup:

"Most applications do not use the full program and parameter RAMs; therefore, 8KB EEPROM is sufficient."

Thank you Brett.

Marti

EEPROM selection for 192KHz fs ADAU1701

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