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ADAU1772, CM Voltage start-up

Question asked by Brian_S_Hansen on Apr 7, 2017
Latest reply on May 4, 2017 by Brian_S_Hansen

 Dear Analog


I have a issue with the start-up time of the ADAU1772 “CM Voltage” (AVDD/2).

This voltage take approx. 150ms on the EVAL Board but approx. 500-600ms on my design.

The only different is the clock (24.576MHz on my design).

I used the same value of CM capacitor 10uF.

If I compare the rise time the value is equal up till the EEPROM load the ADAU.

What register setting can cause this changes? Or what else can have inference on the start-up of the CM voltage?


Best regards



See Picture

CH1= I2C, CH2= Vcm Boot, CH3=3V3, R1= Vcm not Boot