Meaning of Wakeup Pulse Filter Constant in S6BT112A - KBA228428

Version 2

    Author: AtsushiT_61           Version: **

     

    Question:

    What is the meaning of the wakeup pulse filter constant in S6BT112A?

     

    Answer:

    At the Master Node: In the wakeup pulse of the Sleep mode, the transceiver is designed so that a low pulse less than the Trx_wakeup_master value input to the BUS pin is not output to the RXD pin. The RXD pin waveform is delayed by 30 to 150 us with respect to the bus waveform.

     

    At the Slave Node: In the wakeup pulse of the Sleep mode, the transceiver is designed so that a low pulse less than the Trx_wakeup_slave value input to the BUS pin is not output to the CLK pin. The CLK pin waveform is delayed by 0.5 to 5 us with respect to the bus waveform.

     

    Table 1 lists the wakeup pulse filter constant and Figure 1 shows the filtered waveforms at wakeup. For more details, see Table 8-7. AC Characteristics in the S6BT112A datasheet.

     

    Table 1. Wakeup Pulse Filter Constant

     

    Parameters

    Symbol

    Pin Name

    Conditions

    Min

    Typ

    Max

    Unit

    Wakeup pulse filter constant (Master)

    Trx_wakeup_master

    BUS

    NSLP = 0 V

    SELMS = 0 V

    VTH(bus) = 42.3 %

    30

    -

    150

    us

    Wakeup pulse filter constant (Slave)

    Trx_wakeup_slave

    BUS

    NSLP = 0 V

    SELMS = 5 V

    VTH(bus) = 42.3 %

    1. 0.5

    -

    5

    us

     

     

    Figure 1. Filtered Waveforms at Wakeup