AD7986

18-Bit, 2 MSPS PulSAR 15 mW ADC in LFCSP (QFN) AD7986 FEATURES 18-bit resolution with no missing codes Throughput: 2 MSPS (TURBO = high), 1.5 MSPS (TURBO = low) Low power dissipation 15 mW at 2 MSPS, with external reference 26 mW at 2 MSPS with internal reference INL: ±1 LSB typical, ±2.5 LSB maximum SNR 95.5 dB, with on-chip reference 97.0 dB, with external reference 4.096 V internal reference: typical drift of 10 ppm/°C True differential analog input voltage range: ±VREF 0 V to VREF with VREF up to 5.0 V Allows use of any input range No pipeline delay Logic interface: 1.8 V/2.5 V/2.7 V Serial interface: SPI/QSPI™/MICROWIRE™/DSP compatible Ability to daisy-chain multiple ADCs with busy indicator 20-lead 4 mm × 4 mm LFCSP (QFN) V+ 15Ω 0V TO VREF V– V+ 15Ω 2.7nF V– NOTES 1. GND REFERS TO REFGND, AGND, AND DGND. 07956-001 APPLICATION DIAGRAM 5V 2.5V 1.8V TO 2.7V 2.7nF IN+ BVDD AVDD, DVDD VIO TURBO SDI SCK SDO CNV VIO 3- OR 4-WIRE INTERFACE: SPI, CS DAISY CHAIN (TURBO = LOW) AD7986 IN– REF 10µF GND1 VREF TO 0V Figure 1. GENERAL DESCRIPTION The AD7986 is an 18-bit, 2 MSPS successive approximation, analog-to-digital converter (ADC). It contains a low power, high speed, 18-bit sampling ADC, an internal conversion clock, an internal reference (and buffer), error correction circuits, and a versatile serial interface port. On the rising edge of CNV, the AD7986 samples the voltage difference between the IN+ and IN− pins. The voltages on these pins usually swing in opposite pha...