• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 323 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

PCA9306: How we can know PCA9306 ready for communication?

Toshihiro Watanabe
Genius 10235 points
Part Number: PCA9306

Hello,

The customer would like to know the measurement method when PCA9306 is ready for communication.

Due to ceramic capacitor shortage issue, the customer needs to use larger cap than 100pF for REF2 cap. This makes turn on time increase. The issue is how long should we wait the communication for PCA9306 ready.

Would you give us the guidance of the time vs capacitance and how to measure if PCA9306 is ready or not.

Best regards,

Toshihiro Watanabe

  • 0
    TI__Guru 62920 points
    Hello Watanabe-san,

    The PCA9306 will not have a turn-on delay; it will be active as soon as the EN voltage reaches a high enough level. Since EN is used to derive a bias voltage to control the gates of the translating switches, the device can begin to function as soon as this voltage reaches a typical gate threshold value (600-700 mV). The performance of the device may deviate from the datasheet specifications (e.g., different propagation delays, higher series resistance) while the reference voltages ramp up to their normal steady-state values.

    In this case you could compute the RC time constant created by the REF2 capacitor and the series resistance value used (typically 200 kOhm) and wait 3-4 time constants to allow voltages to stabilize before initiating communication.

    I hope this is clear, and please let me know if you have any further questions.

    Regards,
    Max