Analog Devices Unveils Low-Noise, Low-Power 14-Bit SAR ADCs
These 20 and 40 MSPS devices use Easy Drive tech for simple signal chains. Continuous acquisition and a 16K FIFO optimize precision wideband data capture.
Analog Devices recently introduced the AD4086 and AD4087, two high-speed, 14-bit successive approximation register (SAR) ADCs designed for precision wideband data acquisition. The AD4086 delivers a throughput of 40 MSPS with a conversion latency of 48.21 ns, while the AD4087 provides 20 MSPS at 82.14 ns latency.
Analog Devices’ new 14-bit SAR ADCs are available in a 49-ball, 5 mm x 5mm CSP_BGA package. Image used courtesy of Analog Devices
Both devices incorporate Easy Drive features that reduce signal chain complexity and power consumption. These ADCs enable continuous signal acquisition, allowing settling across the entire conversion cycle. Integrated components, including a 16K-sample FIFO and supply decoupling capacitors, further minimize PCB footprint. Typical applications include digital imaging, spectroscopy, and automated test equipment.
The AD4086 and AD4087 SAR ADCs are highly integrated to facilitate system integration. Image used courtesy of Analog Devices
Key Technical Features
- Easy Drive Architecture: This design incorporates circuitry to reduce the nonlinear input current associated with charge kickback. This allows for lower-power, lower-bandwidth drivers and less complex input anti-alias filters.
- Continuous Signal Acquisition: Unlike conventional SAR ADCs that only acquire signals for a fraction of the cycle, these devices acquire for 100% of the conversion cycle. This maximizes settling time for high-precision results.
- Integrated 16K-Sample FIFO: The on-chip memory can store up to 16,384 conversion results. This reduces the data transmission load on host controllers like MCUs and supports asynchronous data capture.
- Precision Performance: Both devices offer excellent dynamic range—85.85 dBFS for the AD4086 and 85.5 dBFS for the AD4087. Signal-to-noise ratio (SNR) is typically 85.34 dB for the AD4086 and 85.39 dB for the AD4087 at 1 kHz.
- Programmable Digital Filtering: Users can choose between Sinc1, Sinc5, or Sinc5 + FIR compensation filter paths. These filters offer decimation rates up to 1024 and optimized pass-band flatness within ±0.1 dB.
