24-bit sigma-delta with integrated PGA — one-chip sensor front-end
The ADS122C04IRTET is a 24-bit sigma-delta ADC with a MUX-PGA-ADC architecture, integrating a programmable gain amplifier (PGA) and an internal temperature sensor directly on the die.
I2C interface and single-supply operation simplify the BOM
Data transfer runs over an I2C interface, using only two bus lines for communication. The analog and digital supply share a single 2.3 V to 5.5 V rail — no dual supplies or separate AVDD/DVDD regulators are needed, which cuts the passive count around the ADC. The internal voltage reference eliminates an external reference IC and its associated bypass capacitors. For applications that need a ratiometric measurement, the reference input can be driven externally, though the internal reference's drift and accuracy suit most industrial sensor interfaces without added cost.
Industrial temperature range and 3x3 mm WQFN package
The 0:1 S/H-to-ADC ratio means there is no sample-and-hold stage — the sigma-delta modulator samples the input continuously, so the input signal must be band-limited to avoid aliasing. An external RC filter ahead of the ADC is standard practice for this architecture.