Meaning of these conditions in the battery charger IC

[FreshmanNewbie]

In this battery charger IC, below is a table.



My question is what does it mean when Vdd=Vbat & Vdd=Vin? I am not sure on what Vdd exactly is? Going through the flowchart and the other table didn't provide much clarity.

Can someone explain me how to understand the highlighted conditions and in what scenarios do they occur?

In my testing, when the "No battery present" condition, both STAT pins should be in High-Z. But in that case, I am getting both are Low only. Any idea on why that happens too?

 

[Externet]

Hi.
Nobody knows what the manufacturer means by VDD, a nasty old habit in electronics as VCC, VBB... nomenclature.
Guessing, when the supply voltage equals the battery voltage, that IC shuts down or disables the charging progress by your chart. If there is no battery inserted, perhaps corresponds to 'Hi Z' , also disabling operation. Some sensor could also be for temperature in the battery, or a type/voltage identification resistor built-in.
It would be convenient to explore the data sheet and application examples of that IC

--- Updated Mar 21, 2023 ---

Page 2 of the data sheet does not show VDD. Later, page 11 equates VDD as supply. Another inconsistency. No VDD first, yes remamed VDD later.

--- Updated Mar 21, 2023 ---

Looking deeper, near the top on page 5 of the data sheet, they give the same voltage 3 names, to make it nastier...

 

[FreshmanNewbie]

Hi.
Nobody knows what the manufacturer means by VDD, a nasty old habit in electronics as VCC, VBB... nomenclature.
Guessing, when the supply voltage equals the battery voltage, that IC shuts down or disables the charging progress by your chart. If there is no battery inserted, perhaps corresponds to 'Hi Z' , also disabling operation. Some sensor could also be for temperature in the battery, or a type/voltage identification resistor built-in.
It would be convenient to explore the data sheet and application examples of that IC

--- Updated Mar 21, 2023 ---

Page 2 of the data sheet does not show VDD. Later, page 11 equates VDD as supply. Another inconsistency. No VDD first, yes remamed VDD later.

--- Updated Mar 21, 2023 ---

Looking deeper, near the top on page 5 of the data sheet, they give the same voltage 3 names, to make it nastier...

Thank you for you comment. Its not clear for me? I feel that the datasheet is very confusing and tricky. What do you think? Did you get any clarity on this topic from the datasheet?

 

[Externet]

Yes, found enough clarity to discern the IC operation from its data sheet. It takes some years merging experience and understanding data sheets. Take VDD, Vin, Vbat as the supply voltage for the circuitry.