The disclosure relates to a controller area network, CAN, transceiver and a CAN controller. The CAN transceiver is configured to: compare a signal from the CAN bus with a negative threshold level; and provide a wake-up indication to the CAN controller based on the signal matching a predetermined pattern of one or more periods in which the signal is less than the negative threshold level. The CAN controller is configured to provide instructions to transmit a wake-up indication on the CAN bus.