AD7985

16-Bit, 2.5 MSPS, PulSAR 15.5 mW ADC in LFCSP AD7985 FEATURES 16-bit resolution with no missing codes Throughput: 2.5 MSPS (TURBO high), 2.0 MSPS (TURBO low) Low power dissipation 15.5 mW at 2.5 MSPS, with external reference 28 mW at 2.5 MSPS, with internal reference INL: ±0.7 LSB typical, ±1.5 LSB maximum SNR 88.5 dB, with on-chip reference 90 dB, with external reference 4.096 V internal reference: typical drift of ±10 ppm/°C Pseudo differential analog input voltage range 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) APPLICATION DIAGRAM 5V 2.5V 1.8V TO 2.7V 0V TO VREF IN+ IN– VIO BVDD AVDD, DVDD TURBO VIO 3- OR 4-WIRE INTERFACE: SPI, CS, DAISY CHAIN (TURBO = LOW) AD7985 GND REF 10µF SDI SCK SDO CNV NOTES 1. GND REFERS TO REFGND, AGND, AND DGND. Figure 1. GENERAL DESCRIPTION The AD7985 is a 16-bit, 2.5 MSPS successive approximation analog-to-digital converter (SAR ADC). It contains a low power, high speed, 16-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 AD7985 samples an analog input, IN+, between 0 V and REF with respect to a ground sense, IN−. The AD7985 features a very high sampling rate turbo mode (TURBO is high) a...