dimensioning of R3 and C4 for the tps61175

Kai Leufker

Prodigy 20 points

Other Parts Discussed in Thread: TPS61175, TPS61088

I’m building a Step Up Converter with the tps61175 device.

My circuit looks like this:

But I still have no idea about R3 and C4.

I Can’t find any helpful information in the Datasheet. Do you have fitting values for the R-C-Net?

The Network Specifications:

Input Voltage: 3,7-7,4V

Output Voltage: 9V(a little bit adjustable, to compensate tolerances)

Output current: up to 2A

Is there a minimum output current?

over 10 years ago

0 Helen chen over 10 years ago

TI__Mastermind 40080 points

Hi Leufker ,
TPS61175 is not fit for this applicaton. The maximum current limit point is 3A, but in Vo=9V, Io=2A application, Iin is much higher than 3A.
I recomend TPS61088, this part will be released at May this year.
You can contact with the local TI FAE for the EVMs and the sample.
By the way, could you please tell me the detailed application, Volume?Regards,
Helen

0 Kai Leufker over 10 years ago in reply to Helen chen

Prodigy 20 points

Ok, the output current is just 1A. The short time peak is 2A so I wrote 2A

It Has to Power a Heater for a Printer

What Volume do you mean?

0 Helen chen over 10 years ago in reply to Kai Leufker

TI__Mastermind 40080 points

Then how short it is? what is the lowest Vo can be accepted?

Usually we design based on the maximum current. Or you have to use a very very big cap at the output.

Power management

Power management forum

dimensioning of R3 and C4 for the tps61175