GENERAL DESCRIPTION
The AD7685 is a 16-bit, charge redistribution successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD, between 2.3 V to 5.5 V. It contains a low power, high speed, 16-bit sampling ADC with no missing codes, an internal conversion clock, and a versatile serial interface port. The part also contains a low noise, wide bandwidth, short aperture delay, track-and-hold circuit. On the CNV rising edge, it samples an analog input IN+ between 0 V to REF with respect to a ground sense IN−. The reference voltage, REF, is applied externally and can be set up to the supply voltage.

FEATURES
   16-bit resolution with no missing codes
   Throughput: 250 kSPS
   INL: ±0.6 LSB typical, ±2 LSB maximum (±0.003% of FSR)
   SINAD: 93.5 dB @ 20 kHz
   THD: −110 dB @ 20 kHz
   Pseudo differential analog input range
      0 V to VREF with VREF up to VDD
   No pipeline delay
   Single-supply operation 2.3 V to 5.5 V with
      1.8 V to 5 V logic interface
   Serial interface SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible
   Daisy-chain multiple ADCs, BUSY indicator
   Power dissipation
      1.4 μW @ 2.5 V/100 SPS
      1.35 mW @ 2.5 V/100 kSPS, 4 mW @ 5 V/100 kSPS
   Standby current: 1 nA
   10-lead package: MSOP (MSOP-8 size) and
      3 mm × 3 mm QFN (LFCSP) (SOT-23 size)
   Pin-for-pin-compatible with 10-lead MSOP/QFN PulSAR® ADCs

APPLICATIONS
   Battery-powered equipment
      Medical instruments
      Mobile communications
      Personal digital assistants (PDAs)
   Data acquisition
   Instrumentation
   Process controls