This document describes the features and characteristics of the 16-bit, 250 kSPS PulSAR ADC AD7685 Rev. B. It has 16-bit resolution with no missing codes and a throughput of 250 kSPS. The INL is typically ±0.6 LSB and maximum ±2 LSB (±0.003% of FSR). The SINAD is 93.5 dB @ 20 kHz and THD is -110 dB @ 20 kHz. The ADC has a pseudo differential analog input range of 0 V to VREF with VREF up to VDD. It operates on a single supply of 2.3 V to 5.5 V with a 1.8 V to 5 V logic interface. The ADC supports serial interfaces such as SPI®-/QSPI™-/MICROWIRE™-/DSP and can be daisy-chained. It has low power dissipation and standby current of 1 nA. The product is available in a 10-lead MSOP (MSOP-8 size) and 3 mm × 3 mm QFN (LFCSP) (SOT-23 size) package.
The AD7685 is a 16‑bit charge‑redistribution successive‑approximation ADC that operates from a single 2.3 V to 5.5 V supply. It offers a 250 kSPS throughput, no missing codes, and a versatile SPI‑compatible serial interface that can be daisy‑chained or used with a BUSY indicator. The part includes a low‑noise, wide‑bandwidth track‑and‑hold circuit and supports both 1.8 V, 2.5 V, 3 V, or 5 V logic levels.
Key specifications include a 16‑bit resolution, INL of +0.6 LSB typical, SINAD of 93.5 dB at 20 kHz, and a standby current of 1 nA. The device is offered in 10‑lead MSOP and 10‑lead QFN (LFCSP) packages and is rated for operation from –40 °C to +85 °C. The datasheet also contains pin descriptions, timing diagrams, absolute maximum ratings, and an ordering guide.