TPS61221: Vin > Vout

Yuta Nishie

Part Number: TPS61221
Other Parts Discussed in Thread: TPS61299,

Hi,

the following thread said "The output voltage will track the input voltage. As Vin goes higher, Vout goes higher. There will be a voltage drop across the IC that is a function of the load current.".

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/33823/what-happen-if-the-input-voltage-is-higher-for-a-boost-converter?tisearch=e2e-sitesearch&keymatch=TPS61221#

Does this work the same when EN= High?

If you have an image like TPS61299, please let me know.

Best Regards,

Nishie

5 months ago

+1 Nini Zhong 5 months ago

TI__Expert 3315 points

Hi Nishie，

The theory of TPS61221 and TPS61299 are totolly different. Therefore there is no imaged as you said.

TPS61221: Vout track Vin because of N MOSFET body diode.

TPS61299: Vout track Vin because of down mode and pass through FET.

0 Yuta Nishie 4 months ago in reply to Nini Zhong

Expert 2440 points

Hi Nini-san,

Thank you for your support.

I understood the difference in internal structure.

What about the other question, "Another question, Does this work the same when EN= High? What about?"?

Best Regards,

Nishie

+1 Nini Zhong 4 months ago in reply to Yuta Nishie

TI__Expert 3315 points

For 221, it's the same case with EN=0. Vin- Vout=Vdiode

For 299, Vout and Vin are truly disconnected.

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TPS61221: Vin > Vout