TJA1043T and TJA1443AT

[rwhitney]

Currently working on a design that utilizes both TJA1043T and will later drop in the form fit functional replacement TJA1443AT. My question is on the pins: EN, STBN, TXD and RXD. In the application hints document, it is shown some type of pull-up or pull-down on those pins but no mention of it is made in the document. Can you please inform me if any of those pins requires a pull-up or pull-down resistor? Or if any of those pins would be improved by the application of a pull-up or pull-down resistor? I am referencing page 40 of 118 in the document: AH1014 Application Hints - Standalone high speed CAN transceiver TJA1042 / TJA1043 / TJA1048 / TJA1051 Rev. 01.50 — 11 Dec 2020 Thank you, Rich

[TomasVaverka · Accepted solution]

Hello Richard,

Pin TXD has an internal pull-up to VIO and pins STB_N and EN have internal pull-downs to GND to ensure a safe, defined state in case one, or all, of these pins is left floating.

Pull-up/pull-down resistors are present on these pins in all states. Pull-down on pin EN is only active when VBAT is present.

As long as STB_N and EN are not correctly driven by the μC during power-on, reset or in case of a system failure, the transceiver stays in Standby mode to prevent the bus to be driven dominant.

If the STB_N and EN pins are not used they shall be connected to VIO to enable a default Normal mode.

Best regards,

Tomas