AD7710 Series

The AD7710 is a complete analog front end for low frequency measurement applications. The device accepts low level signals directly from a strain gage or transducer and outputs a serial digital word. It employs a sigma-delta conversion technique to realize up to 24 bits of no missing codes performance. The input signal is applied to a proprietary programmable gain front end based around an analog modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via the on-chip control register allowing adjustment of the filter cutoff and settling time.The part features two differential analog inputs and a differential reference input. Normally, one of the channels will be used as the main channel with the second channel used as an auxiliary input to periodically measure a second voltage. It can be operated from a single supply (by tying the VSSpin to AGND) provided that the input signals on the analog inputs are more positive than -30 mV. By taking the VSSpin negative, the part can convert signals down to -VREFon its inputs. The AD7710 thus performs all signal conditioning and conversion for a single or dual channel system.The AD7710 is ideal for use in smart, microcontroller based systems. Input channel selection, gain settings and signal polarity can be configured in software using the bidirectional serial port. The AD7710 contains self-calibration, system calibration and background calibration options and also allows the user to read and write the on-chip calibration registers.CMOS construction ensures low power dissipation and a software programmable power down mode reduces the standby power consumption to only 7 mW typical. The part is available in a 24-pin, 0.3 inch-wide, plastic and hermetic dual-in-line package (DIP) as well as a 24-lead small outline (SOIC) package.PRODUCT HIGHLIGHTSThe programmable gain front end allows the AD7710 to accept input signals directly from a strain gage or transducer, removing a considerable amount of signal conditioning.The AD7710 is ideal for microcontroller or DSP processor applications with an on-chip control register that allows control over filter cutoff, input gain, channel selection, signal polarity, and calibration modes.The AD7710 allows the user to read and write the on-chip calibration registers. This means that the microcontroller has much greater control over the calibration procedure.No missing codes ensures true, usable, 23-bit dynamic range coupled with excellent ±0.0015% accuracy. The effects of temperature drift are eliminated by on-chip self-calibration, which removes zero-scale and full-scale errors.APPLICATIONSWeigh ScalesThermocouplesProcess ControlSmart TransmittersChromatography