lpc804 pull up resistor value

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lpc804 pull up resistor value

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yarzartunaung
Contributor I

hello,

could u advise what the value of internal pull up and pull down resistor value for lpc804 is? thanks!

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nxf51211
NXP Employee
NXP Employee

Hi,

The pull-up and pull-down are not passive resistors but active current sources (they typically deliver around 50µA when enabled) that is why there is not a precise value for them. Please refer to the "Ipu"/"Ipd" and "Vi" characteristics in the LPC804 data sheet (Electrical pin characteristics, located at the Table 14, page 48):

pastedImage_1.png

So for example, if a pin at pull-down has a typical Vi of 5V, the current would be of 50µA and therefore the internal resistor value would be of 100 KOhms.

I hope this information can help you, and please ask if you have any more doubts.

Ricardo Delsordo.

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BerlinRaj
Contributor II

how to configure the IOCON register and how to enable the pull down in pio0-7 in  lpc804? give the example

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nxf51211
NXP Employee
NXP Employee

Hi,

The pull-up and pull-down are not passive resistors but active current sources (they typically deliver around 50µA when enabled) that is why there is not a precise value for them. Please refer to the "Ipu"/"Ipd" and "Vi" characteristics in the LPC804 data sheet (Electrical pin characteristics, located at the Table 14, page 48):

pastedImage_1.png

So for example, if a pin at pull-down has a typical Vi of 5V, the current would be of 50µA and therefore the internal resistor value would be of 100 KOhms.

I hope this information can help you, and please ask if you have any more doubts.

Ricardo Delsordo.

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yarzartunaung
Contributor I

thanks Ricardo... 

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