Hello
I've two questions about PCM5242
1. Will I2C become 3.3V when DVDD is supplied by 3.3V as below?
2. Should we leave GPIO floating or tie to GND if they are unused.
Thank you very much!
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Hello
I've two questions about PCM5242
1. Will I2C become 3.3V when DVDD is supplied by 3.3V as below?
2. Should we leave GPIO floating or tie to GND if they are unused.
Thank you very much!
Hi Alex,
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Thank you for your patience,
Jeff
Hello Alex,
The GPIO pins have a pull down resistor to GND so you don't need to do anything with them.
I2C lines usually are pull up to Digital supplies of the target IC with some 2-5K resistors ; if you change the digital supplies, you should pull the signals to the same supply. In your diagram I2C is coming from a controller that may be already 3.3V.
Please refer to pages 16 -21 of " Basics of I2C: Advanced Topics TIPL 6104" for more information on I2C and voltage translation between controller and target device.
Regards,
Arash
Hello Arash
I got you. I'm confused about the digital supple of PCM5242 DVDD(pin 4). If we provide a 3.3V to pin 4, would it become a 3.3V target IC? so that the SDA SCL and I/O should be pull up to 3.3V as the pic shown.
Thanks again.
DVDD is used to set the I/O voltage (and the internal LDO uses this DVDD to generate the 1.8V supply that is required for digital core .)
If you run the DVDD from a 3.3V supply your I/O is 3.3V and you need to pull up to 3.3V .