• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 16 subscribers
  • Views 147 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TRF7962A: Connection of the EN/EN2 pin

rei
Mastermind 6155 points
Part Number: TRF7962A

Hi,
My customers have questions about the EN/EN2 pins of the TRF7962A.

Now customer's design is
EN---VDD_X (1kΩ pull-up)
EN2 ---GND (1kΩ pull-down)

Due to this connection, the IC may enter power-down mode and not work.

Customers suspected that the EN pin was misconnected, so EN pin connected to the power supply same as the VIN.
Then the IC is working properly.
I'm guessing this problem is probably because the EN/EN2 pin mode was determined before the VDD_X internal regulator worked.

Question 1:
Is the above guess correct?

Question 2:
Is it correct to connect the EN pin to the VIN power supply if the EN pin is not controlled by the MCU?

Question 3:
Customer's design, ASK/OOK(12) pin also connect to the VDD_X.
If ASK/OOK is not controlled by the MCU, is it correct to connect to the VIN?

Customers have products that have been sold for several years with this wrong design.
But so far, this problem has not occurred.

Question 4:
Why is it in Standby mode even if the EN pin is connected to VDD_X?

Customers found this design problem and needs to redesign it.
However, they need to explain to END-User why it worked correctly until now.
I’d like to ask you for your help on this problem...

Best regards,
Rei

  • +1
    TI__Mastermind 18265 points

    Hi Rei,

    1. Yes, this guess is correct.

    2. The EN pin has to be connected to VIN and not to VDD_X because the availability of the VDD_X is controlled by the EN pins.

    3. For the AKS/OOK pin the connection to VDD_X is ok.

    4. Because if VDD_X becomes active, depends on EN. If EN is connected to VDD_X the behavior is unpredictable.

    5. This can have different reasons. Raising speed of the supply voltage VIN at power on, process parameters of the device and so on. it is not possible to define the exact reason.

    Hope that helps to answer the customers questions,

    Best Regards,

    Helfried 

  • 0 in reply to Helfried Vollbrecht
    Mastermind 6155 points

    Hi Helfried,

    I appreciate your help! I told the customer these.

    Best regards,

    Rei