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TPS548B28: Output Pin# 20 of P/N TPS548B28

Part Number: TPS548B28

Hello,

We are planning to use the TPS548B28 switcher for a new design.

Pin# 20 is the output pin and is only 0.35mm wide. I'm sure I'm not understanding something but how is such a narrow width supposed to be able to deliver up to 20 amps?

Here is the link to the datasheet:

https://www.ti.com/lit/ds/symlink/tps548b28.pdf?ts=1701301484336&ref_url=https%253A%252F%252Fwww.google.com%252F

The package outline is on page 45.

We're on a tight schedule so your prompt reply is greatly appreciated!

Thanks!

Bill

  • Hi Bill, 

    Pin 20 of the TPS548B28 is the SW node, which doesn't exactly deliver the 20 A output current. The SW sends PWM signals to the output inductor which maintains a steady output current. The image below shows the relationship between the PWM signals from SW and the inductor current. I also included an application note on switching regulator principles. 

    Switching regulator fundamentals (Rev. C) (ti.com)

    Best,
    Ryan

  • Hi Ryan,

    Thank you for your prompt reply. If not pin 20, then from which pin does the 20A flow from?

    Thanks,

    Bill

  • Hi Ryan,

    Thank you for your prompt reply. If not pin 20, then from which pin does the 20A flow from?

    Thanks,

    Bill

  • Hello Bill, 

    yes, the pin can handled the rated current according to datasheet. It can do maximum peak inductor current of 35A. The qualification process confirms that the reliability of our products, processes, and packages meets industry standards. All TI products undergo qualification and reliability testing or qualification by similarity justification prior to release. Common questions about TI’s qualification process can be found here.

    For this device in particular, it's been in the market since 2020 with no returns or any quality issues. As long as the datasheet spec are meet in your design and the recommended operating conditions are followed, the device will handle the current ratings. 

    Thanks 

    Tahar