UC2845A: UCC2845A's UVLO

Masaharu Takahashi

Expert 4170 points

Part Number: UC2845A

Hi, team.

what "Start threshld" and "minimum operation voltage after turnon" mean and its different ?

how do we use 2 below different parameters ?

is there any reason why there are 2 different voltage?

over 4 years ago

0 John Griffin1 over 4 years ago

TI__Mastermind 34465 points

Hello Masaharu,
As the input bias supply voltage supply (Vcc) is increased the start threshold is the voltage that the ic starts operating at.
This is normally called Vcc(on) or UVLO(on)
If you decrease the input voltage from the Vcc(on) value, the ic will eventually turn off.
This is referred to as the "minimum operation voltage after turnon".
It is also called Vcc(off) or UVLO(off)

Regards
John

0 Masaharu Takahashi over 4 years ago in reply to John Griffin1

TI__Expert 4170 points

why are there 2 different voltage overlapped ?

・Start theresholdUVLO turn on: 7.8V ~ 9V
・Minimum UVLO turn off : 7V ~ 8.2V

"UVLO ON 7.8v" is covered in 8.2V (UVLO turn off).
what is this meaning ?

0 John Griffin1 over 4 years ago in reply to Masaharu Takahashi

TI__Mastermind 34465 points

I am listing the UVLO(on) value with the corresponding UVLO(off) in brackets ( ) below for the UC2845A

These value were taken from the table in your first post :

7.8 ( 7 )

8.4 (7.6 )

9 ( 8.2 )

There is 0.8V of a difference between each of these values.

So for example if a device turns on at 9V it will turn off at 8.2V

There is no overlap.

Regards

John

Power management

Power management forum

UC2845A: UCC2845A's UVLO