TPS548A20: About Power Supply Recommendations

Tsukui Yusuke

Guru 21930 points

Part Number: TPS548A20

Hi,

The following contents are described in the data sheet.

1. If the customer follows this statement, the recommended operating input range is 4.5V to 18V (VIN=VDD).
　Is this understanding right?

2. Please tell me why the specifications of VIN and VDD are described separately.
　Customers don't understand why VIN and VDD have different specifications even though TPS548A20 don't support split rail.

Regards,
Yusuke

over 5 years ago

0 David_Daniels over 5 years ago

TI__Mastermind 23685 points

The VIN is the power stage input voltage, ie the power fets.

The VDD is the input voltage for the control circuits.

When 5V is connected on VDD, a voltage of 1.5V can be connected to VIN and converted down to lower voltage.

0 Tsukui Yusuke over 5 years ago in reply to David_Daniels

Guru 21930 points

Hi David,

Thank you for your support.
〉When 5V is connected on VDD, a voltage of 1.5V can be connected to VIN and converted down to lower voltage.
However, the data sheet states:
”These devices are not designed for split-rail operation. The VIN and VDD terminals must be the same potential for accurate high-side short circuit protection.”

Does your usage indicate that it sacrifices the high side short circuit function?

Best regards,
Yusuke

0 Peter James Miller over 5 years ago in reply to Tsukui Yusuke

TI__Guru 56795 points

Tsukui Yusuke

The datasheet note is in error. The TPS548A20 does not have high-side short-circuit protection and is designed to support split-rail operation where VDD and VIN are connected to different potentials.

The TPS548A20 uses its valley current limit and under-voltage protection (UVP) to protect from damage due to a short-circuit on the output.

0 Tsukui Yusuke over 5 years ago in reply to Peter James Miller

Guru 21930 points

Hi Miller,

Thank you for your kind support.
I inform the customer that it can be used with split rails.

>The datasheet note is in error.
Will the content be corrected in the next data sheet revision?

Regards,
Yusuke

0 Peter James Miller over 5 years ago in reply to Tsukui Yusuke

TI__Guru 56795 points

Tsukui Yusuke

You are welcome. And yes, the datasheet will be updated.

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TPS548A20: About Power Supply Recommendations