TPS61236P: TPS61236P concept review and layout question

Ashiful Khurashi1

Part Number: TPS61236P
Other Parts Discussed in Thread: TPS61022

Hi. Attached is the concept I came up with for a 5V output boost converter using the TPS61236P. Can someone help review this? In this application the boost converter can be turned on by a switch. This switch connection can be jumper-ed so when a battery is plugged in the converter will automatically be powered. Also I put in a 47uF electrolytic to help reduce input ringing due to inductance in the battery connection wire. What value is typically recommend? I do not like 1Mohm resistance values due to its high value, so I have considerably reduced resistances as compared to the application note in the datasheet.

For layout, in the datasheet AGND is connected to PGND, however in the PCB layout recommendation they are not connected (to isolate the high frequency noise of PGND it seems). Does or should AGND be connected to PGND?

over 4 years ago

0 Ashiful Khurashi1 over 4 years ago

Prodigy 70 points

Application is 2.7-4.2V battery input, 5V/2.4A output.

0 Ashiful Khurashi1 over 4 years ago

Prodigy 70 points

Sorry I forgot to attach the concept block diagram. I'm also thinking of adding 0.1uF and 1uF caps on VOUT by the output connector of the module.

Inductor value I'm thinking of using is 3.3uH/10A, based on my calculations under worst case conditions and limiting the input peak current to be below 6.5A (minimum ISW current limit from the datasheet).

0 Garrett Roecker over 4 years ago in reply to Ashiful Khurashi1

TI__Mastermind 21720 points

Hi Ashiful,

I have reached out to my colleagues that support this device. They are out of the office right now but will get back to you next week.

Thanks,

Garrett

0 Zack Liu over 4 years ago in reply to Ashiful Khurashi1

TI__Mastermind 34201 points

Hi Ashiful,

TPS61022 is also a good option for you application. You could consider about it.

The input electrolytic capacitor value to reduce input ringing depends on the input wires length and parasitic inductance. I think 47uF is enough if the input wire is not extremely long.

AGND and PGND should be connected together close the IC to set a reference point. Thanks for finding it.

Other parts look good.

Power management

Power management forum

TPS61236P: TPS61236P concept review and layout question