Tool/software:
Hello,
I am currently using a 12-bit ADC resolution.
According to the datasheet of the TPS4H000A, the ADC measurement range is specified from 0.1 A to 0.25 A, and the expected current limit is 0.5 A.
I would like to confirm whether the ADC will output the maximum value of 4095 if the current exceeds 0.25 A on a single channel.
Gyeongjiu,
The way that the current sense works on the TPS4H000-Q1 is that it outputs, through the CS pin, a scaled down version of the load current going from VS to OUTx. Essentially, the current on the SNS pin will be equal to the load current divided by KSNS (80 in the case of TPS4H000-Q1)
For example, if you had 750mA of load current, the SNS pin would have ~9.375mA of current. You can choose the resistor on the CS pin to maximize resolution on your ADC. For example, assuming you have a 5V ADC if you chose a 480ohm resistor, when the 750mA of load current is going through the load you would have 4.5V on the CS pin to be read by the ADC (9.375mA * 470).
The reason you want to leave a little overhead on the ADC range is that because during a fault event, the CS pin is pulled up to an internal voltage to signify a fault condition:
Best Regards,
Tim
