Modify buck regulator for 6.25-6.5V

Hello, I’d like to drop 9-12V to 6.25-6.5V. I see there is Pololu - 2.5-7.5V Adjustable Step-down Voltage Regulator D36V6ALV that has a pot adjuster. I’d like fixed output if possible though. Can you recommend a replacement resistor value for something like Pololu - 6V, 600mA Step-Down Voltage Regulator D36V6F6 to get the output in the range 6.25-6.5? Many thanks!

Hello.

You can increase the voltage of the D36V6F6 regulator by replacing one or two of the resistors on it: R1 and R2:

The 6V D36V6F6 regulator uses R1 = 91kΩ and R2 = 13.3kΩ and the equation for the relationship to the output voltage is:

V_{OUT} = 0.765\text{ V} × (1+\frac{R1}{R2})

So, for example increasing R1 to 100kΩ would give you slightly higher than 6.5V.

Brandon

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Perfect; thanks!

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