About I2C bit rate

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
NoAr_1540581
Level 5
Level 5
Distributor - Macnica (Japan)
5 solutions authored 250 sign-ins 100 replies posted

Hello

We are understanding that the operating frequencies supported are 400 kHz and 1 MHz when VIO5 is 1.8 V, but the customer said that they want to use I2C bit rate as 100kHz when VIO5 is 1.8V.

Is it possible or not?

Best regards

Arai

0 Likes
1 Solution

Hello Arai-san,

When VIO5 is 1.8V, FX3 I2C supports all three frequencies. This can be tested using the FX3 DVK. The firmware image file can be generated for I2C frequency of 100kHz and the VIO5 can be set to 1.8V. The I2C boot of FX3 has been found to be successful indicating that I2C at 100kHz works at VIO5 as 1.8V.

Best regards,

Srinath S

View solution in original post

0 Likes
4 Replies
SrinathS_16
Moderator
Moderator
Moderator
1000 replies posted 750 replies posted 500 replies posted

Hello Arai-san,

I believe you are talking about the FX3 device.

FX3 supports maximum I2C frequency of 100kHz when VIO5 is 1.2V. If VIO5 is 1.8V, FX3 I2C supports I2C frequencies of 100kHz, 400kHz and 1MHz.

Best regards,

Srinath S

0 Likes
NoAr_1540581
Level 5
Level 5
Distributor - Macnica (Japan)
5 solutions authored 250 sign-ins 100 replies posted

Hello Srinath san

FX3 datasheet is described below.

>The I2C controller supports bus frequencies of 100 kHz, 400 kHz, and 1 MHz. When VIO5 is 1.2 V, the maximum

>operating frequency supported is 100 kHz.   """ When VIO5 is 1.8 V,2.5 V, or 3.3 V, the operating frequencies supported are 400 kHz

>and 1 MHz.""""

I am understanding that If VIO5 is 1.8V, FX3 I2C supports I2C frequencies of 400kHz and 1MHz, and 100KHz is not including. Is it correct? If correct, is there any method using 100kHz when VIO5 is 1.8V.

Best Regards

Arai

0 Likes
NoAr_1540581
Level 5
Level 5
Distributor - Macnica (Japan)
5 solutions authored 250 sign-ins 100 replies posted

Hello

Any updates? We have to fix this problem ASAP.

Best Regards,

Arai

0 Likes

Hello Arai-san,

When VIO5 is 1.8V, FX3 I2C supports all three frequencies. This can be tested using the FX3 DVK. The firmware image file can be generated for I2C frequency of 100kHz and the VIO5 can be set to 1.8V. The I2C boot of FX3 has been found to be successful indicating that I2C at 100kHz works at VIO5 as 1.8V.

Best regards,

Srinath S

0 Likes