The Analog Devices AD4854 is a fully buffered, 4-channel simultaneous sampling, 20-bit, 1 Msps DAS with differential, wide common-mode range inputs. Operating from a 5 V low-voltage supply, flexible input buffer supplies, and using the precision low-drift internal reference and reference buffer, the AD4854 allows the SoftSpan range of each channel to be independently configured to match the application signal swing, thereby minimizing additional external signal conditioning. To further maximize the single-conversion dynamic range, the AD4854 incorporates seamless high dynamic range (SHDR) technology. When enabled, the input signal path gain of the channel is automatically optimized on a sample-by-sample basis, minimizing converter noise on each sample without impacting linearity.

The 11 MHz bandwidth, picoamp input analog buffers, wide input common-mode range, and 120 dB common-mode rejection ratio (CMRR) of the AD4854 allow the DAS to directly digitize input signals with arbitrary swings on INx+ and INx-. Its input signal flexibility, combined with ±160 µV integral nonlinearity (INL), no missing codes at 20 bits, 97.2 dB signal-to-noise ratio (SNR), and 111.4 dB dynamic range make the AD4854 an ideal choice for applications requiring high accuracy, throughput, and precision in a compact footprint. Enabling 24-bit oversampling offers further SNR and dynamic range improvements. Optional per-channel offset, gain, and phase adjustment provide the ability to calibrate and remove system-level errors upstream to the DAS.

The AD4854 features a serial peripheral interface (SPI) register configuration bus (0.9 V to 5.25 V) and supports both low-voltage differential signaling (LVDS) and complementary metal-oxide semiconductor (CMOS) conversion data output buses, which are selectable using the LVDS/CMOS pin. Between one and four lines of data output can be employed in CMOS mode, allowing users to optimize bus width and throughput. The 64-ball, 7.00 mm x 7.00 mm ball grid array (BGA) package of the AD4854 includes all critical power supply and reference bypass capacitors, minimizing the full solution footprint and component count, as well as reducing sensitivity to the application printed circuit board (PCB) layout. The AD4854 operates over an extended industrial temperature range of -40°C to +125°C.

The EVAL-AD4858FMCZ evaluation board is designed to demonstrate the performance of the AD4854 and provide access to many included configuration options that are accessed via a simple ACE plug-in graphical user interface (GUI).