• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 15 subscribers
  • Views 292 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.

ISO7720: Supply current and data rate question for ISO7720

user5956241
Intellectual 565 points
Part Number: ISO7720

Hi TIer,

I would like to discuss the supply current ICC2 for ISO7720.

1. If use 5V supply voltage and supply current Icc2 2.2-3mA, the ISO7720 is internal automatic use data rate 3Mbps? right?

2. Is the propagation delay time spec regarding on data rate? 

min 6 ns --> 1Mbps @ Icc1 1.8mA, Icc2 1.3mA

typ 11 ns --> 10Mbps @ Icc1 1.9mA, Icc2 2.2mA

max 16 ns --> 100Mbps @ Icc1 2.5mA, Icc2 11.6mA

  • 0
    TI__Guru 51890 points

    Hi,

    Thanks for reaching out, please allow me answer your questions.

    1. The user will not be able to control device current consumption, we can only operate device for given datarate / test conditions and the current consumption will follow accordingly. When the device is operated with a datarate of 3Mbps with VCC2 = 5V, the max ICC2 is going to be between 1.9mA (1Mbps spec) and 3mA (10Mbps spec).

    2. The datarate doesn't have any impact on propagation delay. Propagation delay variation is due to process (sample-to-sample differences), voltage and temperature. The variation due to supply is already covered by having separate tables for separate VCC voltages. Hence, 6ns to 16ns variation is primarily due to process and temperature.

    Please note that the datasheet min/max propagation range is a statistical worst-case range. During your typical lab testings, you will not see samples hitting those limits. For example, refer to the propagation delay curve Figure 14 provided in the datasheet (also copied below). As shown in this curve, the actual test data is going to be lower than the datasheet limits for most samples. The very few worst-case will get close to the limits.


    Regards,
    Koteshwar Rao

  • 0 in reply to Koteshwar Rao
    Intellectual 565 points

    Hi Sir,

    Thank you very much!

    As your mention, if input signal is PWM and the period is 500kHz. may I know the supply current of ICC2 is  1.3-1.9mA? 

  • +1 in reply to user5956241
    TI__Guru 51890 points

    Hi,

    Yes, your understanding is correct. If the input signal frequency is 500kHz (same as 1Mbps) and VCC2 is 5V, then ICC2 is going to be typically 1.3mA and a max of 1.9mA. Thanks.


    Regards,
    Koteshwar Rao