TPS2121: TPS2121 "seamless" vs TPS2117

THOMAS WALTER

Intellectual 290 points

Part Number: TPS2121
Other Parts Discussed in Thread: TPS2117

Hi all,
I am design a board and would like to replace the tps2121 by the tps 2117 (lower quiescent current).

I ack that there are differences in many parameters : voltage, RDson, ...

I checked all of them but I still have one question about the "seamless" of the 2121 that isn't present in the 2117.

I implemented an automatic priority mode (see picture):

My understanding is that the only difference in behavior is that with 2121, if VBATT (IN2) were to drop below P5V0 (IN1),
IN1 would be selected back, which won't be the case with 2117 as IN1 is compared to internal (1V) reference ?

7 months ago

0 Bandaru Hemanth 7 months ago

TI__Genius 9480 points

Hello,

Thanks for reaching out,

Yes, you are correct, In TPS2117 when PR1 < VREF, even though VIN1>VIN2, if the mode pin connected to high, it won't switch back to IN1, because here mode pin decides whether device should be in diode mode or priority mode,

But in TPS2121, there is not nothing like that, device can switch between XCOMP mode & VCOMP mode, if the respective conditions meet.

Thanks,

Hemanth.

0 THOMAS WALTER 7 months ago in reply to Bandaru Hemanth

Intellectual 290 points

Hi,

Thanks for the precisions.

0 Bandaru Hemanth 7 months ago in reply to THOMAS WALTER

TI__Genius 9480 points

hello,

you are welcome. I'm glad that your issue resolved. Please reach out to me if you have any concerns.

Thanks,

Hemanth.

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TPS2121: TPS2121 "seamless" vs TPS2117