Analog Devices Inc. AD9257 Serial LVDS Analog-to-Digital Converters
Analog Devices AD9257 Serial LVDS Analog-to-Digital Converters (ADCs) are high‑performance, octal, 14‑bit data converters designed to deliver an effective balance of speed, power efficiency, and integration for multi‑channel signal acquisition systems. The ADI AD9257 family operates at sampling rates of 40MSPS or 65MSPS (depending on variant) and integrates eight simultaneous sampling channels with on‑chip sample‑and‑hold circuits, making the devices well-suited for dense, high‑channel‑count applications. These ADCs achieve strong dynamic performance, with a typical signal‑to‑noise ratio (SNR) of about 75.5dB and spurious‑free dynamic range (SFDR) exceeding 91dBc to Nyquist, while maintaining low power consumption of approximately 55mW per channel at 65MSPS.
A serial LVDS (ANSI‑644) output interface significantly reduces pin count and board routing complexity, and complementary data clock (DCO) and frame clock (FCO) outputs simplify data capture in FPGA‑based systems. The converters operate from a single 1.8V supply, support a 2Vp‑p differential analog input range, and provide a wide 650MHz full‑power analog bandwidth, enabling direct interfacing to a broad range of signal sources without external references in many designs. Configuration and monitoring are handled through an SPI‑compatible serial port that allows programmable clock and data alignment, flexible bit orientation, output resolution control, and built‑in or user‑defined digital test patterns for system verification.
In addition to the standard industrial versions, the AD9257 portfolio includes enhanced and space‑grade options tailored for harsh environments. The AD9257S‑CSL variant targets commercial space applications, offering operation over a -55°C to +125°C temperature range along with wafer diffusion lot traceability, radiation lot acceptance testing, and characterization for total ionizing dose (TID) and single‑event effects, while maintaining the same core electrical performance and LVDS interface as the commercial device. Similarly, the AD9257‑EP version is an enhanced product device qualified for defense and aerospace applications under a controlled manufacturing baseline and extended temperature operation, providing long‑term availability and qualification data support. Across all variants, the ADI AD9257 ADCs are optimized for applications such as medical imaging and ultrasound, digital beamforming, quadrature/diversity radio receivers, optical networking, test equipment, and spaceborne payloads, where compact size, channel density, low power, and robust performance are critical design requirements.
Space-Grade ADC
Analog Devices developed a Commercial Space Products Program to address expansions in traditional Geostationary Earth Orbit (GEO) satellite signal-processing applications and Low Earth Orbit (LEO) small-satellite constellations. The program defines screened and qualified commercial-grade components suitable for space applications. Balancing performance, reliability, and cost for missions, the AD9257TCPZ-65-CSL meets the program's requirements.
Features
- Low power - 55mW per channel at 65MSPS with scalable power options
- 75.5dB SNR (to Nyquist)
- 91.6dBc SFDR (to Nyquist)
- ±0.6LSB typical DNL
- ±1.1LSB typical INL
- Serial LVDS (ANSI-644, default) - low power, reduced signal option (similar to IEEE 1596.3)
- Data and frame clock outputs
- 650MHz full power analog bandwidth
- 2Vp-p input voltage range
- 1.8V supply operation
- Serial port control
- Full chip and individual channel power-down modes
- Flexible bit orientation
- Built-in and custom digital test pattern generation
- Programmable clock and data alignment
- Programmable output resolution
- Standby mode
- Small footprint - eight ADCs are contained in a small, space-saving package
- Ease of use - data clock output (DCO) is provided that operates at frequencies of up to 455MHz and supports double data rate (DDR) operation
- User flexibility - SPI control offers a wide range of flexible features to meet specific system requirements
- Pin compatible with the AD9637 (12-bit octal ADC)
- Commercial space variant (-CSL)
- -55°C to +125°C military temperature range
- Wafer diffusion lot traceability
- Radiation lot acceptance test (RLAT) and total ionizing dose (TID)
- Radiation benchmark, single event latch-up (SEL)
- Enhanced product variant (-EP)
- Supports defense and aerospace applications (AQEC standard)
- -55°C to +125°C military temperature range
- Controlled manufacturing baseline
- Qualification data available on request
- RoHS-compliant
Applications
- Medical imaging and nondestructive ultrasound
- Portable ultrasound and digital beam-forming systems
- Quadrature and diversity radio receivers
- Optical networking
- Test equipment
- Low Earth orbit (LEO) space payloads (-CSL variant only)
Specifications
- 14-bit resolution
- 0.5V to 1.3V common-mode voltage range, 0.9V typical
- 7.5kΩ typical input resistance
- 5.2kΩ typical differential input resistance
- 3.5pF typical differential input capacitance
- 1.8V maximum supply voltage
- 1mW typical power-down dissipation
- 75.6dB to 75.9dB signal-to-noise ratio
- 40MS/s or 65MS/s sampling rate options
- 464mW power dissipation
- ±2ppm/°C typical temperature drift offset error
- 650MHz typical analog input bandwidth at full power
- 9mm x 9mm x 0.83mm (LxWxH) LFCSP-64 package
- +260°C peak soldering temperature
Datasheets
Resources
- AN-501 Application Note - Aperture Uncertainty and ADC System Performance
- AN-586 Application Note - LVDS Data Outputs for High-Speed Analog-to-Digital Converters
- AN-812 Application Note - Microcontroller-Based Serial Port Interface (SPI) Boot Circuit
- AN-877 Application Note - Interfacing to High Speed ADCs via SPI
- AN-878 Application Note - High Speed ADC SPI Control Software
Functional Block Diagram
