SLLSFO8C May 2024 – November 2025 TCAN2450-Q1 , TCAN2451-Q1
PRODUCTION DATA
Cyclic Wake can be used to self-wake the device using timer1 or timer2 period without a need for an external wake event. This feature behaves in a specific manner depending upon the SBC mode the device is in and if enabled. This function is available in normal, standby, fail-safe and sleep modes. In normal and standby, at the start of the programmed on time, the device pulls nINT low for programmed-on time and release. The first on time pulse is ignored but each afterward causes the interrupt. Cyclic wake is enabled by using register 8'h25[3] for timer1 or 8'h26[3] for timer2.
This can be enabled in fail-safe mode by using register 8'h0E[6]=1b. As VCC1 is off in fail-safe mode, nINT pin is not used. When enabled, the period selected for the timer needs to be 500ms, 1s or 2s. When the on time takes place, the device determines if a fault is still present. If fault has not cleared, the device stays in fail-safe mode and repeats the process until the SWE timer times out at which time the device transitions to sleep mode. If fault has cleared, this is treated as a wake event and the device transitions to restart mode.
This feature can be enabled in sleep mode by setting register 8'h4F[4]=1b. In sleep mode, the device wakes up and transition to restart mode where the regulators are turned on. Once the device enters standby mode, the programmed long window starts and is expecting a WD trigger from the processor within this window. If this does not take place, the device transitions back to sleep mode. During this process, if a fault is detected the device transitions back to sleep mode.