ad7266差分單端輸入雙路 2位、12位、三通道SAR ADC

　　The AD72661 is a dual， 12-bit， high speed， low power， successive approximation ADC that operates from a single 2.7 V to 5.25 V power supply and features throughput rates up to 2 MSPS. The device contains two ADCs， each preceded by a 3-channel multiplexer， and a low noise， wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 30 MHz. The conversion process and data acquisition use standard control inputs allowing easy interfacing to microprocessors or DSPs. The input signal is sampled on the falling edge of CS; conversion is also initiated at this point. The conversion time is determined by the SCLK frequency. There are no pipelined delays associated with the part. The AD7266 uses advanced design techniques to achieve very low power dissipation at high throughput rates. With 5 V supplies and a 2 MSPS throughput rate， the part consumes 6.2 mA maximum. The part also offers flexible power/ throughput rate management when operating in normal mode as the quiescent current consumption is so low. The analog input range for the part can be selected to be a 0 V to VREF （or 2 × VREF） range， with either straight binary or twos complement output coding. The AD7266 has an on-chip 2.5 V reference that can be overdriven when an external reference is preferred. This external reference range is 100 mV to VDD.