PGA305: Data ready

Hello JW,

There is no hardware solution to receive some kind of interrupt when each new conversion is ready.

The ADC data is stored in a shadow register before being made available to the registers accessible via the digital interfaces, so there is no concern for getting incorrect data if you are reading quickly. You may just read the same data twice in a row if you read again before the next conversion is ready.

Regards,

hello Scott,  the device does not have a input for start of conversion, what triggers an adc conversion

thanks

The PGA305 converts continuously using an internal signal that is not brought out to a pin anywhere.

Hello Scott, is reading from the PDATA_DATA1,  PDATA_DATA2, PDATA_DATA3 one byte at a time the correct method to obtain an a ADC conversion, is there anther method.  the reason I'm asking is the  values  return don't match the expected value when the input of the ADC is shorted, could this be a result of a configuration issue, suggestions?

Because the conversion is continuous, does reading the data in three byte chunks separate by  several hundred micro seconds result in data from different adc conversions, can this be an issue?

the device has a  16 or 24 bits mode, would the results be the same if one were to read only the PDATA_DATA1,  PDATA_DATA2 register?

thanks

hello Scott when you have time, thanks 

Hello,

The conversion data is not directly made available to the PDATA registers. The conversion data is stored in shadow registers, and only when the entire conversion is complete are the data moved to the PDATA registers and made available to the digital interfaces. You will not get data mixed between conversions on the PDATA registers.

Yes, the 16 bit mode data is essentially the same as reading the 2 MSBytes in the 24 bit mode.

If the inputs are shorted, but are outside of the common mode range of the PGAIN, you will likely see unexpected values. What are you seeing and how is the part configured?

Regards,

Hello,  "the 16 bit mode data is essentially the same as reading the 2 MSBytes in the 24 bit mode.", in that case does  24 bit be left at 1?

The compensation control register is set to 0x01, is this correct for a uncompensated measurement over I2C?

Are there other register which need to be set ?

the voltage at the input is derived by a three resistors in series, the PGA reads the voltage across the center resistor,  the input voltage to the PGA is 4mV.

Given a excitation of 2.5V, 4mV input and gain of 5 = 524cnts, is this correct.

thanks