Inquiry regarding I2C logic level on TPS65910

Atsushi Okui

Genius 4015 points

Other Parts Discussed in Thread: TPS65910, AM3517

Hello, all

Now we have some inquiries regarding I2C logic level on TPS65910 from our customer.

Please refer to the items below, and feedback us with your comment.

This customer is evaluating TPS65910 and AM3517, then found mismatched on I2C logic level between these 2 devices.

1) When referring page 8 of TPS65910 datasheet (SWCS046T), VOL(MAX) seems to be 1.32V based on 0.4×VDDIO. (on their application, +3.3V is applied on VDDIO.)

2) When referring page 84 of AM3517 datasheet (SPRS550E), VIL (MAX) of LVCMOS is defined as 0.8V. (on their application, +3.3 is applied on VDDSHV.)

We assume that I2C input is LVCMOS.

Based on above consideration, MPU input (VIL) should exceed MPU input (VIL).

Please let us clarify whether TPS65910 could not drive I2C communication properly if supply voltage is not suitable or with some processor.

We thank you in advance for your information.

Best regards,

over 11 years ago

0 Puneet Sehgal over 11 years ago

TI__Expert 6090 points

Please refer to our refrence design :

Craneboard from Mistral has AM3517+TPS65910.

http://www.mistralsolutions.com/pes-products/development-platforms/craneboard.html

0 Atsushi Okui over 11 years ago in reply to Puneet Sehgal

Genius 4015 points

Hello, thank you for your prompt reply.

As we checked the schematic of Craneboard, we found same configuration as customer's concernings.

When VOL on TPS65910 output is maximum (VDDIO=3.3V then VOL =< 1.32V), the input on AM3517 seems to exceed the low level threshold (VIL =< 0.8).

Therefore, please let us clarify whether I2C communication between 2 devices could be established properly.

We thank you once again for your information.

Best regards,

Power management

Power management forum

Inquiry regarding I2C logic level on TPS65910