TJA1044GT Blockdiagram

[wenfengyao]

About TJA1044GT, is there any imformation introduced VIO and VCC?

How are they connected internally?

[TomasVaverka]

Hi Jacky,

Pin VIO is connected to the microcontroller supply voltage to provide the proper voltage reference for the input threshold of digital input pins and for the HIGH voltage of digital outputs. It defines the ratiometric digital input threshold for interface pins TXD, STB and S and the HIGH-level output voltage for RXD. Both the TJA1057/3 and TJA1044/3 provide a continuous level adaptation from as low as 2.95V to 5.25V.

In general, for a full flexibility between 5V and 3.3V applications it is recommended to use the variants with VIO pin.

Best regards,

Tomas

[wenfengyao]

Hi，Tomas

Can VIO be connected directly to VCC if I am not using STB pin? Will there be any bad effects?

[TomasVaverka]

Hi Jacky,

Yes, it can if it is acceptable to the uC TXD and RXD pins.  

Best regards,

Tomas