TPS929120-Q1: ADC range

Simon Jagla

Part Number: TPS929120-Q1

Hi Champs,

The datasheet states that the analog value of the ADC is calculate as follows:

Analog Value = a+k * ADC_OUT; ADC_OUT being 0 to 255.

when we do the math to measure the supply voltage (channel 2) we end up with a maximum measurable voltage of 20,5693 V:

0.0673 V + 0.0804 V/LSB *255 = 20,5693 V.

which is way below the possible range for the supply (40V).

Are we missing anything?

0 Frank Qiu over 5 years ago

Hi Simon,

the max range of ADC is as you say, i think you can use a divider resistor to measure the voltage.

0 Simon Jagla over 5 years ago in reply to Frank Qiu

Thanks Frank,

We are trying to measure the supply voltage so I don't think you can connect a divider resistor on the SUPPLY pins!?

i did not see a separate pin to measure the supply voltage either.

How is the channel 1 from the ADC multiplexer routed internally? I assumed it is connected directly to the supply pin/voltage.

0 Frank Qiu over 5 years ago in reply to Simon Jagla

Hi Simon,

Your conprehension is right.

I mean you shuold use one output channel to measure the supply voltage with a divider resistor.

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