24位ad7765模数转换器片上缓冲区和串行接口

　　The AD7765 is a high performance， 24-bit sigma-delta （Σ-Δ） analog-to-digital converter （ADC）。 It combines wide input bandwidth， high speed， and performance of 112 dB dynamic range at a 156 kHz output data rate. With excellent dc specifications， the converter is ideal for high speed data acquisition of ac signals where dc data is also required. Using the AD7765 eases the front-end antialias filtering requirements， simplifying the design process significantly. The AD7765 offers pin-selectable decimation rates of 128× and 256×。 Other features include an integrated buffer to drive the reference， as well as a fully differential amplifier to buffer and level shift the input to the modulator. An overrange alert pin indicates when an input signal has exceeded the acceptable range. The addition of internal gain and internal overrange registers makes the AD7765 a compact， highly integrated data acquisition device requiring minimal peripheral components. The AD7765 also offers a low power mode， significantly reducing power dissipation without reducing the output data rate or available input bandwidth