TPS7A54: To check Input voltage tolerance specification

Paul Yeh

Genius 13605 points

Part Number: TPS7A54

Hi team,

We would like to recommend this solution to customer but there is one question from customer.

Need team's explanation and clarification.

Output spec:

1. Vo= 0.9V/3.904A

2. Vo= 0.8V/ 3.3A

Input voltage:
Customer will use 1.1V as input voltage but they should consider the1.1V has 3% tolerance (1.067V~1.133V), so is there any concern?
The Vbias they could use either 3.3V or 5V.

their Vo ripple voltage demand: <=2mV.

Or do you have another suitable solution for suggestion?

Thanks

over 3 years ago

0 Juliette over 3 years ago

TI__Genius 16596 points

Hi Paul,

Figure 23, in the data sheet, shows the drift of dropout voltage vs. output current.

Depending on the operating ambient temperature, the dropout voltage may be greater than the headroom given by the chosen Vin at a 0.9V output and a 3.9A load.

Best,

Juliette

0 Paul Yeh over 3 years ago in reply to Juliette

TI__Genius 13605 points

Juliette,

Thanks for your comment but I think customer is concern Vin min voltage, Although their Vin=1.1V but there should be tolerance, so Vin may be 1.067V, so customer is asking if Vin=1.067V, is this device can support as well?

Thanks

0 Juliette over 3 years ago in reply to Paul Yeh

TI__Genius 16596 points

Paul,

Sorry for misunderstanding. Due to the UVLO of this part, as seen in the 6.5 Electrical Characteristics Table, the device will turn on (at 25°C) with a Vin greater than 1.02V. It will definitely turn on, regardless of temperature, after Vin greater than or equal to 1.085V.

To answer your question, depending on the system and ambient temperature, 1.067V may be sufficient to turn on the device (since it falls between the 1.02V-1.085V Vin range).

In the "Understanding Undervoltage Lockout in Power Devices" App Note, it helps better explain the Operating Modes and Data Sheet Parameters.

Best,

Juliette

0 Paul Yeh over 3 years ago in reply to Juliette

TI__Genius 13605 points

Juliette,

Thanks

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TPS7A54: To check Input voltage tolerance specification