The AD7719 is a complete analog front end for low frequency measurement applications. It contains two high resolution Σ-? ADCs， switchable matched excitation current sources， low-side power switches， digital I/O port， and temperature sensor. The 24-bit main channel with PGA accepts fully differential， unipolar， and bipolar input signal ranges from 1.024 × REFIN1/128 to 1.024 × REFIN1. Signals can be converted directly from a transducer without the need for signal conditioning. The 16-bit auxiliary channel has an input signal range of REFIN2 or REFIN2/2. The device operates from a 32 kHz crystal with an on-chip PLL generating the required internal operating frequency. The output data rate from the part is software programmable. The peak-to-peak resolution from the part varies with the programmed gain and output data rate. The part operates from a single 3 V or 5 V supply. When operating from 3 V supplies， the power dissipation for the part is 4.5 mW with both ADCs enabled and 2.85 mW with only the main ADC enabled in unbuffered mode. The AD7719 is housed in 28-lead SOIC and TSSOP packages.