i.MX ProcessorsのトピックRe: PCA9451 i2c voltage levels

PCA9451 i2c voltage levels

michaelscott2371 — Wed, 12 Mar 2025 13:17:25 GMT

Hey, i saw in the PCA9451 power diagram for imx93 that the voltage levels of the i2c signals are pull up to 1.8 while the imx93 i2c power domain is set to 3.3. and in the EVK design file it is pull up to 3.3V as needed.

i guess its a mistake in the data sheet because the EVK is what works..

(or they confused with imx8M where there the i2c is 1.8V)

also here:

" 1.8 V, the voltage of the I2C interface of the i.MX 93" i guess that's a mistake also right?

Re: PCA9451 i2c voltage levels

JorgeCas — Wed, 12 Mar 2025 18:36:23 GMT

Hello,

PCA9451 can handle I2C voltage levels of 1.8V for communication with MPU.

That 3.3V connection is for I2C level translator. The PMIC has a logic translator, dual supply translating transceiver with auto direction sensing, enabling bidirectional voltage level translation up to 5.5V.

Best regards.

Re: PCA9451 i2c voltage levels

michaelscott2371 — Thu, 13 Mar 2025 07:07:21 GMT

it still doesn't explain the diagram that i have shown.
you put a pull ups to 1.8V for the i2c interface with the PCA9451 on the diagram.
in the EVK:

i2c_pu.png

pca9451.png

it goes to NCC_AON which is 3.3V.

the i2c interface of the imx93 is 3.3V not 1.8V as shown here