ZHCSK43A August 2019 – November 2019 TCAN4551-Q1
PRODUCTION DATA.
When VSUP drops to UVSUP level, the VCC CAN transceiver regulator loses the ability to maintain 5 V output. At this point, the UVCCFLTR interrupt flag is set and the TCAN4551-Q1 turns off the regulator and place the CAN transceiver into a standby state. If VSUP returns to minimum levels the device enters standby mode. If VSUP continues to decrease to the power on reset level, the TCAN4551-Q1 shuts everything down. When VSUP returns to acceptable levels the device will come up the same as initial power on. All registers are cleared and the device has to be reconfigured.
| VSUP | Internal LDO | DEVICE STATE | BUS | RXD_INT |
|---|---|---|---|---|
| > UVSUP | > UVCCFLTR | Normal | Per TXD_INT | Mirrors Bus |
| < UVSUP | NA | Protected | High Impedance | High (Recessive) |
| > UVSUP | < UVCCFLTR | Protected | High Impedance | High (Recessive) |
NOTE
Once an under voltage condition and interrupt flags are cleared and the VSUP supply has returned to valid level, the device typicallys need tMODE_CHANGE to transition to normal operation. The host processor should not attempt to send or receive messages until this transition time has expired. If EN is low and VSUP has an under voltage event, the device goes into a protected mode which disables the wake up receiver and places the RXD_INT output into a high impedance state.