TCAN4550-Q1: Is there any method to reduce standby current?

Hi Nicky,

Thank you for your question.  

I'd love to get some more feedback on your customer's application space for the TCAN4550-Q1.  What is the generic end-equipment that they are targeting?  What advantages within the TCAN4550-Q1 are drawing them to consider the device?  

When we evaluate supply current, it is important to note that the TCAN4550-Q1 is a system-basis chip that includes both the transceiver and the CAN FD controller in a single-chip solution.  This means that the current consumption, even in Standby Mode, will be higher than a normal CAN transceiver in the TI portfolio.  Even in Standby Mode, the TCAN4550-Q1 needs to support the configuration of the CAN FD controller.  This is why the TCAN4550-Q1 specifies a maximum standby current of 3.5mA from VSUP in its datasheet.  In addition, any load current drawn from the VCCOUT LDO will add to Standby Mode VSUP current.  

You will only see current numbers in the uA region (25-42uA) when you place the TCAN4550-Q1 into Sleep Mode.  In this mode, the CAN FD controller and transceiver are mostly shutdown, and more significant current savings apply.  

On another note, you can take advantage of some current savings on the VIO supply if you elect to operate the input clocking mechanism of the TCAN4550-Q1 via a CLKIN signal from a microcontroller or other source.  With a CLKIN signal, you can drop the VIO Standby Mode current to 800uA or less.  If you choose the traditional crystal oscillator as the clocking mechanism, then the current consumption on the VIO pin will be up to 3mA.  

There is an important takeaway in this discussion.  Each customer must create a strategy that minimizes overall system-level power consumption.  Current saved from the TCAN4550-Q1 may mean current gained from another module in the system.  Often times, trade offs apply in any system design.  That is why it is important to gather feedback on each customer's application, what power consumption for which they are designing, when power savings are important for them, and when higher power is required in their application.

The short answer to your question: No, the TCAN4550-Q1 is not designed for <1mA VSUP current in Standby Mode.  

The long answer to your question: Since the TCAN4550-Q1 takes on more system level features (CAN FD controller, Watchdog, LDO supply), how can the customer tailor the advantages of the SBC to get the most out of the device for their system needs?  

Let me know if I can clarify any of the information above.  If your customer wants more information about any of the device features within the TCAN4550-Q1, I would be happy to provide more.

Thank you,

Max Megee

TI Transceiver Interface