BQ24073: Vout vs. Vout(reg) Clarification

Hayden_Hast

Part Number: BQ24073

Hello,

I just want to confirm my understanding of the Vout operation for the BQ24073.

When a Vin source is detected (charger connected) Vout is regulated to meet the Vout(reg) voltage of 4.4V. However, when a Vin source is not detected and a battery is present, the Vout voltage will be equal to Vbat - Vdo (50mV due to the Q2 FET conduction losses), it is no longer regulated (boosted in this case) up to 4.4V. Correct?

If my understanding above is correct, I was wondering if there is any efficiency information on a USB charger (5Vin) being regulated down to the 4.4V.

Thanks,

Hayden

over 8 years ago

0 Raheem over 8 years ago

TI__Mastermind 21590 points

Hello Hayden,
The regulation is actually done by a linear regulator. Unfortunately, I don't believe we have the efficiency information.
-Raheem

0 Hayden_Hast over 8 years ago in reply to Raheem

TI__Intellectual 1515 points

Sharafadeen,

Thanks for the info. I understand that the Vin to Vout(reg) is regulated by a linear regulator (unfortunate that we don't have that efficiency info), but you didn't address my question regarding if the battery voltage is boosted up to Vreg(out) when there is no charger connected.

Thanks,
Hayden

0 Raheem over 8 years ago in reply to Hayden_Hast

TI__Mastermind 21590 points

Hayden,

When there is no input connected, the device is in supplement mode as stated below and the output is about 250 mV below the Battery Voltage.

0 Hayden_Hast over 8 years ago in reply to Raheem

TI__Intellectual 1515 points

Thanks Sharafadeen, should be good to go for now.

- Hayden

Power management

Power management forum

BQ24073: Vout vs. Vout(reg) Clarification