SBOU024C august 2004 – july 2023 PGA309
The compensation for the sensor span and offset drifts is driven by the temperature sense circuitry. Either internal or external temperature sensing is possible. The temperature can be sensed in one of the following ways:
The temperature signal is digitized by the onboard Temp ADC. The output of the Temp ADC is used by the control digital circuit to read data from the Lookup Table in an external EEPROM, and set the output of the Gain DAC and the Zero DAC to the calibrated values as temperature changes.
An additional function provided through the Temp ADC is the ability to read the VOUT pin back through the Temp ADC input mux. This provides flexibility for a digital output through either One-Wire or Two-Wire interface, as well as the possibility for an external microcontroller to perform real-time custom calibration of the PGA309.