AD7866

a FEATURES Dual 12-Bit, 2-Channel ADC Fast Throughput Rate 1 MSPS Specified for VDD of 2.7 V to 5.25 V Low Power 11.4 mW Max at 1 MSPS with 3 V Supplies 24 mW Max at 1 MSPS with 5 V Supplies Wide Input Bandwidth 70 dB SNR at 300 kHz Input Frequency Onboard Reference 2.5 V Flexible Power/Throughput Rate Management Simultaneous Conversion/Read No Pipeline Delays High-Speed Serial Interface SPI TM/QSPITM/ MICROWIRE TM/DSP Compatible Shut-Down Mode 1 ␮A Max 20-Lead TSSOP Package Dual 1 MSPS, 12-Bit, 2-Channel SAR ADC with Serial Interface AD7866 FUNCTIONAL BLOCK DIAGRAM VREF DCAPA REF SELECT AVDD DVDD 2.5V REF VA1 VA2 BUF 12-BIT SUCCESSIVEAPPROXIMATION ADC AD7866 OUTPUT DRIVERS DOUTA MUX T/H CONTROL LOGIC A0 RANGE SCLK CS VDRIVE VB1 VB2 MUX T/H 12-BIT SUCCESSIVEAPPROXIMATION ADC OUTPUT DRIVERS DOUT B BUF AGND AGND DCAPB DGND GENERAL DESCRIPTION The AD7866 is a dual 12-bit high-speed, low power, successiveapproximation ADC. The part operates from a single 2.7 V to 5.25 V power supply and features throughput rates up to 1 MSPS. The device contains two ADCs, each preceded by a low-noise, wide bandwidth track/hold amplifier which can handle input frequencies in excess of 10 MHz. The conversion process and data acquisition are controlled using standard control inputs allowing easy interfacing to microprocessors or DSPs. The input signal is sampled on the falling edge of CS and conversion is also initiated at this point. The conversion time is determined by the SCLK ...