PCA9698DGG is not working

[JHKIM7]

Hi ALL

I am evaluating PCA9698DGG, but PCA9698DGG is not working.

You can see the waveform and schematic as like below.

The waveform capture conditions are below.

1. SCL frequency : 400KHz
2. Slave address 0x4E
3. Command register : 0x08
4. Data : 0xFF
5. OE pin : GND
6. MCU : ATMEGA128

Some strange thing is that SDA signal is very fast drop down after received ACK.

Also, I had changed SCL frequency and Slave address, but result is same.

Could you please help this issue?

Best regards.

JH Kim

[JHKIM7]

Hi

Regarding to datasheet, output enable when OEPOL = 1.

But in my case, output enable when OEPOL = 0

Is PCA9698DGG datasheet correct on OEPOL and OE Pin?

Thanks

JH Kim

[guoweisun]

OEPOL bit controls the polarity of OE pin.
– OEPOL = 0: OE pin is active LOW.
– OEPOL = 1: OE pin is active HIGH (equivalent to OE pin).

when OEPOL set to 0,low OE active.

[JHKIM7]

Hi 

The pull up resistors are located at MCU side. The value is 1.5Kohm.

I think normal working I2C, but PCA9689 output is "0" level under below condition.

1. SCL frequency : 400KHz
2. Slave address 0x4E
3. Command register : 0x08
4. Data : 0xFF
5. OE pin : GND
6. MCU : ATMEGA128

I think PCA9689 output is high level under upper condition.

I don't know what's wrong with no output.

Could you please adivce?

Thanks,

JH Kim

[guoweisun]

1: What's the result when your drop down the frequency?

2:what's the pull up resistors of SDA/SCL of PCA8698?