LM27313: LM27313 UVLO

KW Shi

Prodigy 30 points

Part Number: LM27313

Hi Expert,

Why do we involve SW voltage in UVlO circuit?

I guess that Vin drop to low and the Vsw keep high at the same

Q1 will turn off and Vshdn will be low,

Controller will turn off immediately.

How do you think what I said?

If my expectation is not right, please give me direction.

over 7 years ago

0 Jing Ji over 7 years ago

TI__Intellectual 2655 points

Hi KW,
I am in the training this week, I will reply later.

0 Jing Ji over 7 years ago

TI__Intellectual 2655 points

Hi KW,
Could you share full SCH for me?

0 KW Shi over 7 years ago in reply to Jing Ji

Prodigy 30 points

Hi Jing Ji,

Okay! please help find the attachment about SCH.

Thank you

Kyle oled_20180525.pdf

0 Jing Ji over 7 years ago in reply to KW Shi

TI__Intellectual 2655 points

Hi KW,
Sorry for the delay.
1 The reason why involve SW: this will make C1 voltage to SW voltage. when boost works, voltage of C1 = VOUT.
2 This circute seem to set VIN UVLO, but LM27313 has a UVLO=1.5V, I guss you want to set a higher UVLO by this circute.
3 Could you tell me where did you find this circute? So we can think the purpose of this.

0 KW Shi over 7 years ago in reply to Jing Ji

Prodigy 30 points

Hi Jing Ji,

Thank you for replying me.

The website I saw was as below.

http://www.ti.com/product/LM27313/technicaldocuments

Let us talk more about this.

Thank you

Kyle

Power management

Power management forum

LM27313: LM27313 UVLO