The AD7715 is a complete Analog front end for low frequency measurement applications. The part CAN accept low level input signals directly from a transducer and outputs a serial digital word. It employs a sigma-delta conversion technique to realize up to 16 bits of no missing codes performance. The input signal is applied to a proprietary programmable gain front end based around an AnalogModulator The Modulator output is processed by an on-chip digital Filter The first notch of this digital FilterCAN be programmed via the on-chip control Register allowing adjustment of the Filter cutoff and output update rate. The AD7715 features a differential Analog input as well as a differential reference input. It operates from a single supply (+3 V or +5 V). It CAN handle unipolar input signal ranges of 0 mV to +20 mV, 0 mV to +80 mV, 0 V to +1.25 V and 0 V to +2.5 V. It CAN also handle bipolar input signal ranges of 20 mV, 80 mV, 1.25 V and 2.5 V. These bipolar ranges are referenced to the negative input of the differential Analog input. The AD7715 thus performs all Signal Conditioning and conversion for a single-channel system. The AD7715 is ideal for use in smart Microcontroller or DSP based systems. It features a serial Interface that CAN be configured for three-wire operation. Gain settings, signal polarity and update rate selection CAN be configured in software using the input serial port. The part contains self-calibration and system calibration options to eliminate gain and offset errors on the part itself or in the system. CMOS construction ensures very low power dissipation, and the power-down mode reduces the standby power consumption to 15 W typical at 3 V operation. The part is available in a 16-pin, 0.3 inch-wide, plastic dual-in-line package (DIP), a 16-lead 0.3 inch-wide small outline (SOIC) package and in a tiny 16-lead Thin Shrink Small Outline Package (TSSOP). By Analog Devices, Inc.
