ZHCSEG6E December 2015 – December 2019 TCAN330 , TCAN330G , TCAN332 , TCAN332G , TCAN334 , TCAN334G , TCAN337 , TCAN337G
PRODUCTION DATA.
The device has internal pull ups and pull downs on critical terminals to place the device into known states if the pin floats. See Table 1 for details on pin bias conditions.
| PIN | PULL UP or PULL DOWN | COMMENT |
|---|---|---|
| TXD | Pull up | Weakly biases TXD toward recessive to prevent bus blockage or TXD DTO triggering. |
| STB | Pull down | Weakly biases STB terminal towards normal mode. |
| S | Pull down | Weakly biases S terminal towards normal mode. |
| SHDN | Pull down | Weakly biases SHDN terminal towards normal mode. |
The internal bias should not be relied on by design, especially in noisy environments, but should be considered a fall back protection. Special care needs to be taken when the device is used with MCUs using open drain outputs. TXD is weakly internally pulled up. The TXD pull up strength and CAN bit timing require special consideration when this device is used with an open drain TXD output on the microprocessor's CAN controller. An adequate external pull up resistor must be used to ensure that the TXD output of the microprocessor maintains adequate bit timing input to the CAN transceiver.