• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 87 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.

TPS92390: Questions about efficiency and usage conditions.

Kazuya Nakai59
Guru 21575 points
Part Number: TPS92390

Tool/software:

Hello guys,

One of my customers is considering using TPS92390 for their new products.

At this moment, they have the following questions.
Could you please give me your reply?

Q1.
They are thinking for 2 kind of usage.
Usage1:
2 channel mode (OUT1-2 short, OUT3-4 short)
VDD=3.3V, VIN=3V~6V, Vout=7V, Io=700mA total(350mA*2)

Usage2: 
1 channel mode (OUT1~4 short)
VDD=3.3V, VIN=3V~6V, Vout=14V, Io=350mA total

They want to know efficiency example.
Do you have any document or data for it?

Q2.
Could you please tell me whether the following conditions are no problem or not?
1. VDD=0V, VIN=3V~6V. (Is there any description in the device datasheet?) 
    If No.1 answer is "no problem", how much is input current of VSENSE_P, VSENSE_N on each usage?
    Also please give me if there is any terminal treating on each usage.

2. They want to turn on/off VDD with VIN is applied 3V~6V.
    Is it no problem?

3. Can TPS92390 operate correctly under VIN(3.0~3.3V) < VDD (3.3V) condition?

4. Can TPS92390 operate correctly under VIN(3.0~4.2V) < VDD (3.3V) condition?

Your reply would be much appreciated.

Best regards,
Kazuya.   

  • 0
    TI__Mastermind 34780 points

    Hi Kazuya,

    Q1: We don't have efficiency data exactly meet these two usage condition. Customer can refer to Figure 6-2 and Figure 6-3 for reference.

    Q2:

    1. Do you mean only supply VIN but no VDD? In this case, the IC will not start up.

    2. If customer purpose is to shut down the device, it is more recommended to on/off EN.

    3. Yes

    4. Yes

    BR

    Patrick

  • 0 in reply to Patrick Yao
    Guru 21575 points

    Hi Patrick,

    Thank you very much for your reply and I'm sorry that my question is not enough about Q2-1 and Q2-2.

    About Q2-1, my answer is yes.
    Power supply condition in their system has VIN is supplied(3V~6V) but VDD is not supplied(0V).
    It is OK for them that the IC will not start up. They want to know whether TPS92390 has any damage or not.
    Or they know whether the condition is not allowed or not?

    Also they want to know how much is input current of VSENSE_P, VSENSE_N when the condition above is allowed.

    About Q2-2,
    The customer purpose is not to shut down the device.
    In their system, the conditions, VDD turning on(3.3V) and off(0V) when VIN is supplied(3V~6V) can not be avoided.
    Is it not allowed to turn on/off VDD with VIN is applied 3V~6V?

    Thank you again and best regards,
    Kazuya.

  • 0 in reply to Kazuya Nakai59
    TI__Mastermind 34780 points

    Hi Kazuya,

    It is ok to toggle VDD, the IC will be shut down because of VDD UVLO. And will recover when VDD is back.

    I don't have the data of the current flow into VSENSE_P and VSENSE_N, but it should be very small.

    BR

    Patrick