Hi all
I am looking to minimize power consumption on a voltage Translation from 4.2V to 1.8V.

At the moment I have voltage translation with the BSS138


The original circuit is made with 10k resistors, which is giving around 600uA current usage

Changing the circuit with 1M resistors, I can limit the current to around 6uA

But..

will the current be enough to create the voltage on the GPIO input pins (OUT)
How can I figure out how much current is needed on the GPIO input?



Best regards
Viggo

 

Datasheet.

 

Datasheet.

Hi,

In the datasheet, output drive strength is defined. But I cannot find any reference to input drive, how is this detail usually described in the datasheet?

Best regards
Viggo

 

GPIO input pins of what? MCU? Which one? There is sometimes a rating for maximum source impedance depending on what the GPIO connects to in the MCU. That can be as low as 10 K for comparators, as I recall (e.g., 500 uA @ 5V).

 

hi Viggo,
It should be easy to check by building a simple test circuit.
Check the switching hi/lo with a range of frequencies.
E

 

GPIO input pins of what? MCU? Which one? There is sometimes a rating for maximum source impedance depending on what the GPIO connects to in the MCU. That can be as low as 10 K for comparators, as I recall (e.g., 500 uA @ 5V).

Yes, it is the nrf9160 SIP, https://infocenter.nordicsemi.com/pdf/nRF9160_PS_v1.2.pdf.

Thanks, I will look for that specification

 

hi Viggo,
It should be easy to check by building a simple test circuit.
Check the switching hi/lo with a range of frequencies.
E

Will do

 

Here's one table from the datasheet with requirements for the ADC:



I did not read the whole datasheet carefully.