SLLSEZ4A August 2019 – November 2019 TCAN4551-Q1
PRODUCTION DATA.
Sleep mode is similar to the standby mode except the SPI interface and INH is disabled. As the low power CAN receiver is powered off of VSUP the implementer can turn off VIO. The nWKRQ pin is powered off the VSUP supply internal logic level regulator. This allows the TCAN4551-Q1 to provide an interrupt to the MCU when a wake event takes place with out requiring VIO to be up. When the device goes into sleep mode the power to the registers and memory is removed to conserve power. This requires the device to be re-configured prior to being put into normal mode. As the SPI interface is turned off the only ways to exit sleep mode is by a wake up event, RST pin toggle or power cycle. A sleep mode status flag is provided to determine if the device entered sleep mode through normal operation or if a fault caused the mode change. Register 16'h0820[23] provides the status. If a fault causes the device to enter sleep mode, this flag is set to a one.
NOTE
Difference between sleep and standby mode
NOTE
When entering sleep mode it is possible for the TCAN4551-Q1 to assert an interrupt due to UVCCFLTR event as the LDO is powering down. This interrupt should be ignored or can be masked out by using 16'h830[22] before initiating the go to sleep command.