E520.14 Datasheet, PDF (20/41 Pages) ELMOS Semiconductor AG – Provides four HS-CAN physical interfaces

Quad CAN transceiver
PRODUCTION DATA – FEB 4, 2014
E520.14
4.3.3 Automatic Bus Biasing
In state ACTIVE and TR bit or RC bit is set the CAN bus biasing is switched on to VCC/2.
In low power modes bus biasing can be automatically switched on and off. If bits TR and RC are unset, and bits
BIAS and WU are set the bus biasing is switched on if a wake up pattern is detected. In this case RC bit is set and
bus receiver is connected to pin RXD after t . CAN,ON,BIAS
The bus biasing is switched off if no activity is detected on the bus for longer than tsilence or bit BIAS is unset. It is
recommended to set bit CFG.INH = H in state SLEEP if pin INH controls external power supply. Otherwise external
µC is not supplied.
CAN off and wakeable
Ini
Bias off
1
Bias off
2
Bias off
3
Bias off
Enabling CAN in
state ACTIVE
*¹ Bus biasing after wake up enabled
automatically when corresponding
bit BIAS set in CAN configuration
4
Bias on *¹
Bus dominant for t>t_FILTER
t_TO,WAKE expired
Bus recessive for t>t_FILTER
t_TO,WAKE expired
Bus dominant for t>t_FILTER
t_TO,WAKE expired
BWuaskreeucepsdseivteecftoerdt>t_FILTER
No activity on bus
fAoNr _{Dlondgeevrictehasntil}t_{lSiInLElNoCwE}
power state STANDBY
OR BIAS switched off
Fig. 4: HS-CAN bus biasing
Elmos Semiconductor AG reserves the right to change the detail specifications as may be required to permit improvements in the design of its products.
Elmos Semiconductor AG
Data Sheet 20 / 41
QM-No.: 25DS2014E.02