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LMQ66430-Q1: LMQ66430-Q1 data sheet in the Orderable Part Number

Part Number: LMQ66430-Q1

Hello Team,

LMQ66430-Q1 data sheet in the Orderable Part Number column, I could see LMQ66430MC3RXBRQ1 is used for fixed and Adjustable version can you explain me how this IC can understand is it fixed or adjustable version from the application?

Usually there will be pin which we connect to supply or ground, internally the IC can understand based on the external connection it is a fixed or adjustable type.




  • Hi Bhupathi,

    Normally for Buck regulators, the device creates an output voltage with respect to the voltage at FB (for this device, it's 1V). Fixed output devices still have FB referred to some voltage like 1V, but they have the resistor divider network inside the chip.

    Without going into too much details about the internals, this device has a mechanism built to to see if it's been connected directly to VOUT, or if it's been connected with a resistor divider network. It uses some logic to determine if it uses the output of the fixed output voltage resistor divder or the ADJ output voltage.