16-Channel, Easy Drive Multiplexed SAR ADC with Averaging Filters Per Channel

The AD4691/AD4692 are compact, high accuracy, 16-channel, 16- bit successive approximation register (SAR) analog-to-digital converters (ADCs) optimized for high-density multichannel precision data acquisition solutions. The AD4691/AD4692 combine precision performance with Easy Drive features and flexible digital processing to ensure compatibility with space-constrained analog front-end (AFE) designs and low-power digital hosts.

The AD4691/AD4692 Easy Drive features broaden the selection of compatible amplifiers and voltage references. The precharge buffers enable smaller and lower power AFE designs by significantly reducing input voltage and current transients that typically force AFEs to include high-bandwidth ADC driver amplifiers per channel. The WLCSP model also includes an integrated reference buffer which provides a true, buffered reference input.

The AD4691/AD4692 digital features and serial interface are optimized for use with low-power or power-cycled microcontrollers. The AD4691/AD4692 include averaging filters per channel and a customizable channel sequencer, which combined enable on-chip noise filtering with channel-independent averaging ratios. An integrated burst sampling timer enables autonomous and burst sampling schemes to perform conversions with minimal digital resources. Device configuration and ADC data readback are supported via a robust, 4-wire serial peripheral interface (SPI) with optional cyclic redundancy check (CRC).

The AD4691/AD4692 are available in a 5mm × 5mm, 32-lead lead frame chip scale package (LFCSP) and a 2.96mm × 2.96mm, 36-ball wafer level chip scale package (WLCSP) with operation specified from −40°C to +125°C.

APPLICATIONS

* Optical power monitoring

* Medical instrumentation

* Electronic test and measurement

* Automated test equipment

* Battery-powered equipment

* Easy Drive features enable compact system designs

* Precharge buffers reduce analog input and reference circuit drive requirements

* On-chip reference buffer (WLCSP only)

* Small footprint, big performance

* Sample rate: 500kSPS (AD4691) and 1MSPS (AD4692)

* INL: ±0.85 LSB maximum

* Guaranteed 16-bit, no missing codes

* First conversion accurate

* SINAD: 93dB typical, fIN = 1kHz

* 14.6mW at fS = 1MSPS and 7.3mW at fS = 500kSPS

* 32-lead 5mm × 5mm LFCSP or 36-ball 2.96mm × 2.96mm WLCSP