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 phases between 0 V and VREF. It features a very high sampling rate turbo mode (TURBO = high) and a reduced power normal mode (TURBO = low) for low power applications where the power is scaled with the throughput.

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 VREFwith VREFup 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)

APPLICATIONS
Battery-powered equipment
Data acquisition systems
Medical instruments
Seismic data acquisition systems