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TPS63070: Query regarding output current at different operating voltages

Part Number: TPS63070
Other Parts Discussed in Thread: TPS63802, TPS63020, TPS61022

Hello,

 

We have identified TPS63070 for one of our project .

 

This will be used as Buck boost converter to power the board from battery input. Presently we are looking for 3.6V battery . We may use 6V battery if required.

 

Below are the 2 cases of application.

 

Use case 1

Vin min

2

V

Vin Max

3.7

V

Vout  1

3.3

V

Vout Max

1.9

A

Use case 2

Vin min

2

V

Vin Max

3.7

V

Vout  2

4.1

V

Vout Max

1.9

A

 

When we tried to do simulation in TI web bench . This is simulating only up to 1A and above 1A it is giving error.

 

I doubt whether any duty cycle limitation is causing this problem ?

 

As per datasheet switch can be used for 2 A current rating in both boost and buck mode and there is seamless transfer will happen from boost to buck or buck to boost.

 

Please clarify whether this chip will work for above input and output requirement.

 

Thanks

  • Hi Yash:

    Sorry. It's pubilc holiday here. We will back tomorrow. Please wait with patience. Thanks for your kindly understanding!

  • Hi Yash:

    Sorry for keep you waiting. 

    It's hard for TPS63070 to supply such large current for all Vin range. The root cause is the current limit, not duty circuit. 

    The current limit is aimed to the input current, and the minimal value listed in datasheet is 3100mA. According to the equation: Iin=Vout*Iload/Vin/ Efficiency. We could know it's exceed the spec.That's why the simulation notice error.

    We have  TPS63802, which have larger current capability. But it still couldn't meet your requirements.It's hard for a buck-boost converter to support 2V to 4.1/2A.

    As you mentioned you may use 6V battery. It will be easier to select a proper buck-boost converter with higher Vin.

  • Hi Yash:

    I closed the thread assuming that you had solved the issue. if not, just reply below.

  • Hi Minqiu,

    Thanks for the reply.

    Can you kindly suggest the min input voltage for the TPS63070 to support 2A at output? You can suggest for both the parts i.e TPS63070 and TPS63802.

    Kindly let us know if it can support 2A for the range of : for ex: 2.5V to 3.7V. for the previously mentioned two schemes.

    We are now not planning to use double cell for 6V. 

    If not, Kindly suggest any other converter suitable for the mentioned operation.

    Regards,

    Yash Verma

  • Hi Yash:

    I have have some data in hand in our lab. It's typically value and just for reference. Both of them are tested in room temperature. 

    TPS63070 can supply 2A/3.8V when Vin larger than 3.1V. 

    TPS63802 can supply 2A/3.3V when Vin larger than 2.4V. 

    Generally speaking, TPS63802 has stronger current capability. 

    I'll recommend you to apply EVM and do some bench test. It will do some help for debug.

  • HI Minqiu,

    Thanks for the reply.

    Although, we were evaluating TPS63802 as well, but since it is in preliminary stage, we are planning to evaluate TPS63020.

    Please let us know if TPS63020 would be fine for the following two scenarios:-

    Use case 1

    Vin min

    2

    V

    Vin Max

    3.7

    V

    Vout  1

    3.3

    V

    Vout Max

    1.9

    A

    Use case 2

    Vin min

    2

    V

    Vin Max

    3.7

    V

    Vout  2

    4.1

    V

    Vout Max

    1.9

    A

    If not, please suggest the min input voltage and the voltage window for it(TPS63020) to support 2A at both the configurable outputs mentioned above.

    Is it possible for you to kindly let us know if among the two (TPS63802 and TPS63020), which one shall we consider.

    Thanks,

    Yash Verma

  • Hi Yash:

    TPS63020 can supply 2A/3.3V when Vin larger than 2.5V in our lab. I afraid they also hard to support the 2V Vin with full load. 

     

    I wonder if you need same part for these two case? For the Case 2 , the boost converter is much suitable, as tps61022.

  • Hi Minqiu,

    Thanks for your support and quick replies.

    Yes, we need the same part for the two mentioned cases (buck-boost).

    Please also let me know if the part TPS63020 can support 2A/4.1V with Vin Max as 3.7V and also let me know what should be the Vin min (is it 2.5V)?

    Thanks.

    regards,

    Yash Verma

  • Hi Yash:

    The TPS63020 can support 2A/4.1V with Vin larger than 3.2V. It seems a little far away from your sepc.

    What's your application? We wonder if there is other better choice or trade off.

  • Hi Minqiu,

    Thanks for the info.

    We are actually planning to have a battery (rated 3.6V) to support power requirements of GSM module (4.1V/2A) and in other case for supporting power requirement for another wireless modules (3.3/2A).

    Please let me know.

    Regards,

    Yash Verma

  • Hi Minqiu,

    Adding to the above, the peak current is 2A at 4.1V for GSM module, and continuous current is 700mA.

    We are planning to use the same converter when instead of GSM, we will mount another wireless module, with 3.3V supply and 2A peak.

    Thanks

    Best regards,

    Yash Verma

  • Hi Yash:

    3.3V supply for 4.1V/2A is near the boundary. I'll recommend you test in the EVM firstly.

    If the load is just continuous for few seconds, add large capacitance may do some help.