Features and Benefits
- Low noise: 2.4 nV/√Hz input referred voltage noise at maximum gain setting
- Wide input signal bandwidth: 500 kHz at 1.2 MSPS sample rate, 16-bit resolution
- Additional sample rates supported: 300 kSPS, 450 kSPS, 600 kSPS, 900 kSPS, and 1.8 MSPS
- 4 differential simultaneous sampling channels
- No active antialiasing filter required
- Selectable equalizer
- LNA and PGA with 45 dB gain range in 6 dB steps
- Flexible data port supports serial or parallel mode
- Supports FSK mode for FMCW radar systems
- On-chip 1.5 V reference
- Internal oscillator/PLL input: 16 MHz to 54 MHz High speed serial data interface
- See datasheet for additional features
The ADAR7251 is a 16-bit, 4-channel, simultaneous sampling analog-to-digital converter (ADC) designed especially for applications such as automotive LSR-FMCW or FSK-FMCW radar systems. Each of the four channels contains a low noise amplifier (LNA), a programmable gain amplifier (PGA), an equalizer, a multibit Σ-Δ ADC, and a decimation filter.
The front-end circuitry is designed to allow direct connection to an MMIC output with few external passive components. The ADAR7251 eliminates the need for a high order antialiasing filter, driver op amps, and external bipolar supplies. The ADAR7251 also offers precise channel-to-channel drift matching.
The ADAR7251 features an on-chip phase-locked loop (PLL) that allows a range of clock frequencies for flexibility in the system. The CONV_START input and DATA_READY output signals synchronize the ADC with an external ramp for applications such as FSK-FMCW radar.
The ADAR7251 supports serial and parallel interfaces at programmable sample rates from 300 kSPS to 1.8 MSPS, as well as easy connections to digital signal processors (DSPs) and microcontroller units (MCUs) in the system.
- Automotive LSR systems
- Data acquisition systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
The ADAR7251 is a 16bit Delta-Sigma ADC designed for 24GHz/77GHz Radar systems in a 7 mm x 7mm LFCSP-SS package.
Evaluation Board Overview
The ADAR7251 mini board allows a user to program, debug and evaluate the performance of the ADAR7251. Its small form factor makes it the ideal hardware for evaluation of Radar systems using the easy interface to MMIC and DSP. The MMIC and DSP Board (SDP-B) are available from the www.analog.com or contact ADI sales. The GUI for the board can be downloaded.
Evaluation Kit Contents
- Evaluation Board with 5V Adapter
The 24 GHz radar sensor platform called Demorad is a novel microwave radar evaluation platform solution with out-of-the-box software examples and easy startup of radar sensor all done within minutes. Demorad platform enables rapid product prototyping aimed at R&D interests in investigating radar and developing radar sensor products that can measure real-time information such as target/object presence, its movement, angular position, velocity, and range from the sensor.
The Demorad platform provides both hardware and software that allows for very fast evaluation and development of 24 GHz radar without the need to have RF microwave and signal chain system expertize, and significantly reduces development time and system expertize during product development phases.
A high performance RF and analog full signal chain including DSP processing, that is, an RF to bits solution is provided that allows for flexible processing on raw acquisition data, allowing radar experiments on a state-of-the art level hardware in a very short time.
Full software support of 24 GHz radar ICs using a software graphical user interface (GUI) and in DSP radar support function libraries with added capability to write raw data for post processing on PC using Matlab tools.
Figure 1. Demorad 24GHz Evaluation Software Window showing Range-Doppler mode.
The Demorad uses ADI’s 24 GHz, multichannel radar solution. The sensor consists of a single PCB with 2 transmitter/4 receiver antennas on the front side connected to the 24 GHz RF chipset and data acquisition ADC’s and DSP on the reverse side. This forms the basis for a reference design that customers can use to build their final product design.
Figure 2. Demorad full signal chain.
The Demorad uses FMCW radar to detect range and velocity of objects up to 200 m away with a resolution of approximately 75 cm. The field of view (FOV) is approximately 120° in azimuth and 15° in elevation based on the antenna array design. By combining antennas as used in digital beam forming (DBF), the Demorad uses DBF to calculate angular information in the FOV.
Figure 3. Demorad system setup.
- Traffic monitoring and car parking
- UAV/drone collision avoidance and altimeters
- Monitoring and security systems
Features & Benefits
This evaluation board is obsolete and no longer recommended. The replacement board is the TinyRad Demonstration Platform.
- Out-of-the-box Radar demonstration platform.
- Evaluates 24GHz Radar chipset
- Antenna to bits functionality.
- Accompanying software GUI to evaluate:
- Range Doppler
- Digital Beam Forming.
Documentation & Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Support & Discussions
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.