TH8061 Datasheet, PDF (28/36 Pages) Melexis Microelectronic Systems – Voltage Regulator with integrated LIN Transceiver

TH8061
Voltage Regulator with integrated LIN Transceiver
5. Operating during Disturbance
5.1 Operating without VSUP or GND
The absence of V_SUP or GND connection will not influence or disturb the communication between other bus
nodes. No reverse supply of the IC can appear if without GND or VSUP connection the BUS pin is on VBAT
level.
5.2 Short Circuit BUS against VBAT
The reaction of the IC depends on the send state of the transceiver:
- Recessive LIN bus is blocked, no influence to the TH8061
- Dominant
Current limitation, thermal shut down of TH8061 if power dissipation will make an
overrun of T_J
5.3 Short Circuit BUS against GND
LIN bus is blocked. No influence on the TH8061.
5.4 Short Circuit TxD against GND
The LIN transceiver is permanently in the dominant state, that means the whole LIN bus. This state can only
be detected from the LIN controller. In this case the controller must switch off the LIN node via the EN input
of the TH8061. A thermal shut down of TH8061 will appear if the power dissipation and will make an overrun
of T_J.
5.5 TxD open
The internal pull-up resistor forces the LIN node to the recessive state. The communication between the
other bus-nodes will not be disturbed.
5.6 Short Circuit VCC against GND
The VCC pin is protected via a current limitation. This state is comparable with the behaviour in the sleep
mode.
5.7 Overload of VCC
Thermal switch off
The power dissipation is increasing if the load current is between I_{VCC_max} and I_LVCC. If the max junction
temperature of >155°C is reached, the IC will be switched off. The voltage regulator will also be switched off
and a reset signal is forced.
Over current
If the current limitation is active the voltage on VCC drops down. If this voltage under-runs the threshold
V_RES, a reset will be forced.
5.8 Undervoltage VSUP, VCC
The reset unit ensures the correct behaviour of the driver during under-voltage. The BUS pin generates the
recessive state if V_CC < V_MRes. The inputs EN and TxD have pull-up and pull-down characteristics.
If V_MRes ≤ V_CC ≤ 4.5V the TxD signal is transmitted to the bus. The receive mode is also active.
5.9 Short circuit RxD, RESET against GND or VCC
Both outputs are short circuit proof to VCC and ground.
TH8061 – Datasheet
3901008061
Page 28 of 36
June 2004
Rev 007