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Estimation method of internal pull-up/pull-down resistance

Estimation method of internal pull-up/pull-down resistance

KatsumasaH_16
Employee
Employee
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Original KBA:  内部プルアップ・プルダウン抵抗値の見積もり方法

Estimate the resistance values of the pins of pull-up / pull-down resistors inside the device to help the user consider whether a separate external pull-up / pull-down resistor needs to be fitted.

         Check the guaranteed operating range of VCC in the data sheet.

·         Next, check the DC characteristics of the pin leaks (ILI, ILO).

·         Calculate the resistance value based on the relationship of Resistance = Voltage / Current.

Example:

VCC = 3.3 V, ILI/ILO = 2.0 uA

Internal resistance = 3.3V / 2.0uA = 1.65 Mohm

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