MC33664 - INTB and Sleepmode

[Patrick_Pavle]

Dear Community,

does the tranceiver only set an interrupt for a wakeup sequence or for every incoming message?

the interrupt is set by the MC33664until its enable pin is set to high again, i.e. it is set to normal operation. Is the message from the MC33771B then stored by the MC33664 in a buffer until it is back in normal operation or how does this work?

I wonder what happens to the messages from the MC33771B when the MC33664 is in sleep mode.

[TomasVaverka]

Hello Patrick,

The MC33664 activates the INTB pin only when a valid wake-up sequence is detected. The INTB pin remains LOW until the rising edge of the EN pin places the device in Normal mode. The MC33664 exits Sleep mode and enter Normal mode when the MCU enables the device through the EN pin.

BR, Tomas

[Patrick_Pavle]

Hello @TomasVaverka ,

But how does the MC3377x know whether it has to send a wake-up sequence or not?

My MC33664 should be in sleep mode by default and only be active when messages are sent or received.

Can the MC3377x recognize when the transceiver is in sleep mode?

What happens to the message from the MC3377x if the MC33664 is not changed in normal mode in time?

BR, Patrick 

[TomasVaverka]

Hello Patrick,

I do apologize for the delay in answering your question, some of my colleagues attended a technical training this week and therefore I had to manage significantly higher number of customer's questions than usual resulting in a longer response time.

I would recommend you to take a closer look at our AN13117 - Using the MC3377x to wake up the BMS master, which describes in details how the MC3377x can be used to implement a monitoring of the battery while the battery management controller is in sleep mode. It gives a short introduction to the MC3377x and the functional blocks involved in the monitoring and wake functionality. The AN also highlights the most important configuration registers and provides some hints for the hardware configuration of the entire BMS system.

The AN13117 requires an NDA and can be downloaded from:

https://www.nxp.com/webapp/sd/collateral/1644500884161696440643?version=2.0

This AN13117 along with the AN13281 - HVBMS daisy chain communication guide should help you understand the whole concept of the monitoring and wake capability of either MC33771/MC33772 or MC33775.

BR, Tomas