TPS62090 - Webench simulation data(Vin=5V, Vout=1V, Iout=3.0A) and switching frequency(Fs)

Hirotaka Matsumoto

Other Parts Discussed in Thread: TPS62090

Hi all

Would you mind if we ask TPS62090?

Our customer will use TPS62090 as following conditions;
-Vin : 5V
-Vout : 1V
-Iout : 3A
-Fsw : 2.8MHz(FREQ pin connects to GND)

<Question1>
When we simulate above conditions of Vin, Vout and Iout, we could not simulate.
Then, it showed the message "For Vout<0.6V, current limit of 1.5A is being exceeded for the given design condtions during startup." on pop-up window "Parts Not Found". Please refer to the attached file.
3644.20151023_TPS62090_Webench simulation.pdf
So, is it possible to achieve above condtions? or not?

<Question2>
We could not find out the switching frequency on the datasheet P6 at above conditions;
It will be approximate 2.2 MHz, won't it?

Kind regards,

Hirotaka Matsumoto

over 9 years ago

0 Britt Brooks - Online Design Tools over 9 years ago

TI__Mastermind 41310 points

Matsumoto-san,

We are taking a look at the device and its WEBENCH® support. I have verified your results. The design is created if the output current is lower than 2.2A.

Thanks for your patience.

0 Nikhil Gupta (Product Folder Models) over 9 years ago in reply to Britt Brooks - Online Design Tools

TI__Mastermind 39210 points

Matsumoto-san,

This device has a smaller current limit value when the device is starting up (please refer to the soft start section in the datasheet for details). Hence it will not be able to startup into full load like you are asking for in your inputs. Hence that design fails. In this device the expectation is that the application will startup into a lighter load and after startup is over, it can switch to full load.

If you need full load right from the beginning of the startup, please consider another device from our portfolio (WEBENCH can help you get more solutions). If you are ok with starting up into a lighter load, you can still use this device.

Thanks,

0 Chris Glaser over 9 years ago in reply to Nikhil Gupta (Product Folder Models)

TI__Guru*** 148780 points

Nikhil, I'm not sure he requires the device to start into 3A. Is the load at startup a parameter in the inputs? The TPS62090 can support a normal 3A load.

To your second question, the frequency will be lower but 2.2 MHz is a good idea of what it could be.

0 Nikhil Gupta (Product Folder Models) over 9 years ago in reply to Chris Glaser

TI__Mastermind 39210 points

Chris,

That is what I recommended as well in case it is ok not to start into full load. The load that is entered in WEBENCH is the same load during and after Startup.

0 Hirotaka Matsumoto over 9 years ago in reply to Nikhil Gupta (Product Folder Models)

Guru 27585 points

Britt san, Chris san, Nikhil san

Thank you for your great help.

Kind regards,

Hirotaka Matsumoto

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TPS62090 - Webench simulation data(Vin=5V, Vout=1V, Iout=3.0A) and switching frequency(Fs)