The AD7794 is a low power, complete analog front end for low frequency measurement applications. It contains a low noise 24-bit - ADC with six differential inputs. The on-chip low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC. The device contains a precision low noise, low drift internal reference for absolute measurements. An external reference can also be used if ratiometric measurements are required. Other on-chip features include programmable excitation current sources and a bias voltage generator for temperature applications along with 100 nA burnout currents. For pressure and weighscale applications, a low-side power switch is available to power down the bridge between conversions to minimize the power consumption of the system. The device can be operated with the internal clock or, alternatively, an external clock can be used if synchronizing several devices. The output data rate from the part is software programmable and can be varied from 4 Hz to 500 Hz.