Analog Devices Inc. AD7682 & AD7689 16-Bit 250kSPS PulSAR ADCs

Analog Devices Inc. AD7682 and AD7689 16-Bit 250kSPS PulSAR Analog-to-Digital Converters (ADCs) are designed for multi-channel, low power data acquisition applications. These highly-integrated devices contain all the components required, including a 16-bit Successive-Approximation-Register (SAR) ADC with no missing codes, a 4-channel (AD7682) or 8-channel (AD7689) low crosstalk multiplexer, an internal low drift reference and buffer, a temperature sensor, a selectable one-pole filter, and a channel sequencer. These components are configured through an SPI-compatible, 14-bit register. Conversion results, also SPI compatible, can be read after or during conversions with the option for reading back the configuration associated with the conversion.

The AD7682 and AD7689 ADCs provide the user with an on-chip track-and-hold and do not exhibit pipeline delay or latency. These devices are specified from 2.3V to 5.5V and can be interfaced with any 1.8V to 5.0V digital logic family.

The AD7682 and AD7689 are available in a tiny 20-lead lead frame chip scale package (LFCSP) or 20-lead wafer level chip scale package (WLCSP) with operation specified from -40°C to +85°C. The AD7689 includes an extended temperature range model with specifications guaranteed to a maximum temperature (T_MAX) of +125°C.

Features

16-bit resolution with no missing codes
4-channel (AD7682)/8-channel (AD7689) multiplexer with choice of inputs
Unipolar single-ended
Differential (GND sense)
Pseudo-bipolar
Throughput: 250kSPS
INL: ±0.4LSB typical, ±1.5LSB maximum (±23ppm or FSR)
Dynamic range: 93.8dB
Signal to noise and distortion (SINAD): 92.5dB at 20kHz
Total harmonic distortion (THD): -100dB at 20kHz
Analog input range: 0V to V_REF with V_REF up to VDD
Multiple reference types
- Internal selectable 2.5V or 4.09V
- External buffered (up to 4.096V)
- External (up to VDD)
Internal temperature sensor (TEMP)

Channel sequencer, selectable 1-pole filter, busy indicator
No pipeline delay, SAR architecture
Single-supply 2.3V to 5.5V operation with 1.8V to 5.5V logic interface
Serial interface compatible with SPI, MICROWIRE, QSPI, and DSP
Power dissipation
- 3.5mW at 2.5V/200kSPS
- 12.5mW at 5V/250kSPS
Standby current: 50nA
Operating temperature range
- AD7682/AD7689: -40°C to +85°C
- AD7689C: -40°C to +125°C
Package options
- LFCSP-20 (4mm × 4mm)
- WLCSP-20 (2.4mm × 2.4mm)
RoHS compliant