Description

The AD7708 / AD7718 are complete analog front-ends for low frequency measurement applications. The AD7718 contains a 24-bit sigma delta ADC with PGA and can be configured as 4/5 fully-differential input channels or 8/10 pseudo-differential input channels. Two pins on the device are configurable as analog inputs or reference inputs. The AD7708 is a 16-bit version of the AD7718. Inputs signal ranges from 20mV to 2.56V can be directly converted using these ADCs. Signals can be converted directly from a transducer without the need for signal conditioning.The device operates from a 32 kHz crystal with an on-board 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 ratThe part operates from a single 3 V or 5 V supply. When operating from 3 V supplies, the power dissipation for the part is 3.84 mW typ. Both parts are pin-for-pin compatible allowing an upgradable path from 16 to 24 bits without the need for hardware modifications. The AD7708 / AD7718 are housed in 28-lead SOIC and TSSOP packagesAPPLICATIONS Industrial Process Control Instrumentation Pressure Transducers Portable Instrumentation Smart Transmitters