TheAD7798/AD7799 are low power, low noise, complete analog front ends for high precision measurement applications. The AD7798/AD7799 contains a low noise, 16-/24-bit Σ-Δ ADC with three differential analog inputs. The on-chip, low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC. With a gain setting of 64, the rms noise is 27 nV for the AD7799 and 40 nV for the AD7798 when the update rate equals 4.17 Hz.On-chip features include a low-side power switch, reference detect, programmable digital output pins, burnout currents, and an internal clock oscillator. The output data rate from the part is software-programmable and can be varied from 4.17 Hz to 470 Hz.The part operates with a power supply from 2.7 V to 5.25 V. The AD7798 consumes a current of 300 μA typical, whereas the AD7799 consumes 380 μA typical. Both devices are housed in a 16-lead TSSOP package.ApplicationsWeigh scalesPressure measurementStrain gauge transducersGas analysisIndustrial process controlInstrumentationPortable instrumentationBlood analysisSmart transmittersLiquid/gas chromotography 6-digit DVM