TPS25833-Q1: Voltage Range

Hi Mehmet,

Can you share your schematic to me, and where is your test point and what is the condition for the 5.45 level?

Thanks,

Kuno.

Hi Kuno,

Thank you for your respond. 

I am sorry to tell you that I cannot share with you my schematic. However I can share the referance design which done by TI. To be honest, I copied all the edges of this design. The only change is Rlim value. In referance design, they wanted 3A and 5V. Therefore they did with a putting Rlim equal to 12.1k. But in my design I wanted to set the current equal to the 1.5A. Therefore I put Rlim equal to 26.1k. 

 Actually, there is one more thing. They did Rmon is equal to 2.74k. I putted 12.1k. and Rsns is 300 ohm.

I shred a type-c. And I used its GND and Vbus pins to connect DC Electronic Load. I setted the current 1.5A. It worked. I get the current. However I saw the voltage is around 5.45V. 

In addition to that, I used a multimeter to measure what is the voltage is going to the Type-C port. I used a capacitor which is near to Type-C's Vbus. I saw the voltage is equal to 5.55V.

Regards,TIDM117 (7).PDF

By the way, when there is no load at the output. It gives the voltage 5.09V. 

Hi Kanu,

I also share the same guess with you. I think Its about Rmon resistor value. 

Yes, I checked Rsns value one more time right now. It is 0.015 ohm.

Thanks,

Mehmet.

May be I have to decrease Rmon value?

Thank you Kuno. It worked.

Hi again Kuno,

I am sorry but I have to ask someting else.

As I said before, I did Rsns value is equal to the 0.015 ohm and therefore, Rlim value is 26.1kohm. According to this value, I get the current that I wanted to set. (which is 1.5A). However the datasheet say that Vsns should be 50mV. 

According to my design, Vsns value is 0.0225V. (1.5A x 0.015ohm)

If I change Rsns value to 0.033ohm, I get Vsns equal to 50mV however I have to change the Rlim value to get 1.5A. (should change 26.1k to 12kohm.) ( you can find the equation in the attachment.)

My question is that really necessary to Vsns value equal to 50mV? or 0.0225V value is also OK? The reason I asked this is, I dont want to change my layout alot.

Regards,

Mehmet.