GENERAL DESCRIPTION
The AD4697/AD4698 are compact, high accuracy, low power,
8-channel, 16-bit, 500 kSPS/1 MSPS, multiplexed input precision,
successive approximation register (SAR) analog-to-digital converters
(ADCs) with Easy Drive features and extensive digital functionality.
The AD4697/AD4698 are optimal for use in space constrained,
multichannel, precision data acquisition systems and monitoring
circuits. The AD4697/AD4698 feature a true 16-bit SAR ADC core
with no missing codes, an 8-channel, low crosstalk multiplexer, a
flexible channel sequencer, overvoltage protection clamp circuits on
each analog input, on-chip oversampling and decimation, threshold
detection and alert indicators, and an autonomous conversion (autocycle)
mode.
The AD4697/AD4698 Easy Drive features relax the drive requirements
of the analog front end (AFE) and reference circuitry. Analog
input high-Z mode and reference input high‑Z mode simplify system
designs, reduce component count, and increase channel density
by removing the need for dedicated high speed ADC drivers and
reference buffers. The WLCSP option of the AD4698 includes an
internal reference buffer, which provides a true, buffered reference
input.
Input overvoltage protection clamps on each analog input protect
the AD4697/AD4698 from overvoltage events and prevent overvoltage
events on one channel from degrading performance on other
channels (see Figure 27).
Advanced digital functionality makes the AD4697/AD4698 compatible
with a variety of low power digital hosts. The low serial peripheral
interface (SPI) clock rate requirements, on-chip customizable
channel sequencers, and oversampling and decimation reduce the
burden on the digital host system. Autocycle mode and threshold
detection features enable low power, interrupt driven firmware design
by performing conversions autonomously and generating alerts
based on channel specific threshold limits.
The AD4697/AD4698 are available in a 4.00 mm × 4.00 mm,
24-lead lead frame chip scale package (LFCSP) and the AD4698 is
available in a 2.960 mm × 2.960 mm, 36-lead wafer level chip scale
package (WLCSP). All packages are specified with operation from
−40°C to +125°C.

FEATURES
► Easy Drive
► Reduced analog input and reference drive requirements
► On-chip reference buffer (WLCSP only)
► Overvoltage protection up to 5 mA on each analog input
► Long acquisition phase, ≥71.5% (715 ns/1000 ns) of cycle time at 1 MSPS
► High performance
► Sample rate: 500 kSPS (AD4697) or 1 MSPS (AD4698)
► INL: ±1 LSB maximum
► Guaranteed 16-bit, no missing codes
► SINAD: 93 dB typical, fIN = 1 kHz
► Oversampled dynamic range: 111.2 dB, OSR = 64
► Small footprint, high channel density
► 24-lead, 4.00 mm × 4.00 mm LFCSP
► 36-lead, 2.960 mm × 2.960 mm WLCSP
► Easy Drive features support system level designs with fewer components
► Enhanced digital functionality
► First conversion accurate, no latency or pipeline delay
► Fast conversion time and dual-/quad-SDO modes allow low SPI clock rates
► Customizable channel sequencer
► On-chip oversampling and decimation
► Threshold detection alerts
► Offset and gain correction
► Autonomous conversion (autocycle) mode
► 1.14 V to 1.98 V logic SPI
► Low power
► 8 mW at fS = 1 MSPS and 4 mW at fS = 500 kSPS
► 4 μW standby power dissipation with the internal LDO disabled
► Internal LDO enables 3.15 V to 5.5 V, single analog supply operation
► Wide operating temperature range: −40°C to +125°C

APPLICATIONS
► Photodiode monitoring
► Medical instrumentation
► Vital signs monitoring
► Electronic test and measurement
► Automated test equipment
► Instrumentation and process control
► Battery-powered equipment