Analog Devices Inc. ADAR7251WBCSZ-RL

Overview

ADAR7251WBCSZ-RL from Analog Devices is a 4-channel, 16-bit simultaneous-sampling continuous-time Σ-Δ ADC optimized for automotive LSR-FMCW/FSK-FMCW radar front ends. It integrates LNA, PGA (45 dB gain range in 6 dB steps), equalizer, on-chip 1.5 V reference, and PLL with 16–54 MHz input clock support. At 1.2 MSPS, it delivers 94 dB SNR, 2.4 nV/√Hz input-referred noise at max gain, and −40°C to +125°C operation in a 48-lead LFCSP_SS package.

For engineers reviewing the ADAR7251WBCSZ-RL datasheet, ADAR7251WBCSZ-RL pinout, ADAR7251WBCSZ-RL application, or ADAR7251WBCSZ-RL equivalent, key selection criteria include simultaneous 4-channel acquisition timing, FSK mode support for radar ramp synchronization, channel-to-channel phase mismatch ≤0.04°, and integrated digital interface flexibility (serial/parallel/PPI) with SPI control and GPIOs.

Technical Context

The ADAR7251WBCSZ-RL implements four independent analog signal chains, each comprising a low-noise amplifier, programmable-gain amplifier, configurable equalizer (four corner frequencies: 32–54 kHz), multibit Σ-Δ modulator, and decimation filter. Its continuous-time architecture eliminates need for external antialiasing filters and driver op amps.

It features dual-domain clocking: an internal PLL accepts 16–54 MHz master clock (MCLKIN) and generates 115.2 MHz internal clock; conversion timing is synchronized via CONV_START and DATA_READY signals for precise FSK-FMCW radar ramp alignment. The auxiliary 8-bit ADC supports 112.5–450 kHz sampling for auxiliary monitoring tasks.

Key Specifications

Pinout & Package

ADAR7251WBCSZ-RL is housed in a 48-lead, 7 mm × 7 mm, 0.25 mm pitch LFCSP_SS package with exposed thermal pad requiring solder connection to PCB ground plane per JEDEC JESD51 standards (θJA = 25°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar radar analog front-end ADC applications.

Compared with ADAR7251WBCSZ-RL, the ADAR7252WBCSZ-RL extends sample rate headroom while maintaining full compatibility, whereas the ADS131M04IPBSR trades radar-optimized features for general-purpose precision-making ADAR7251WBCSZ-RL the optimal balance of integration, timing determinism, and automotive qualification for LSR/SRR systems.

Availability

ADAR7251WBCSZ-RL is available at Aetrix Electronics and suitable for automotive radar systems, industrial FMCW sensors, and high-reliability data acquisition systems requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant performance.

Supply support for ADAR7251WBCSZ-RL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design centers worldwide and ISO/TS 16949-certified manufacturing.

The ADAR7251WBCSZ-RL belongs to Analog Devices' ADAR radar AFE product line, engineered specifically for automotive and industrial millimeter-wave radar systems requiring simultaneous multi-channel acquisition, ultra-low noise, and functional safety compliance.

FAQ

What is the maximum sample rate supported by the ADAR7251WBCSZ-RL?

The ADAR7251WBCSZ-RL supports programmable sample rates from 300 kSPS up to 1.8 MSPS across all four channels simultaneously. This maximum rate is achieved with decimation ratio = 48 and internal PLL enabled. At 1.8 MSPS, the input signal bandwidth reaches 900 kHz, enabling high-resolution range profiling in FMCW radar applications.

Does the ADAR7251WBCSZ-RL require an external clock source or can it operate with its internal oscillator?

The ADAR7251WBCSZ-RL supports both configurations: it can accept an external 16–54 MHz single-ended clock on the XIN/MCLKIN pin, or drive an external crystal (typically 19.2 MHz) between XIN and XOUT pins for internal oscillator operation. The internal PLL then generates the required 115.2 MHz core clock - no external oscillator IC is needed.

How does the ADAR7251WBCSZ-RL achieve channel-to-channel phase matching below 0.04 degrees?

The ADAR7251WBCSZ-RL achieves <0.04° interchannel phase mismatch through matched analog front-end layouts, laser-trimmed capacitor arrays in the Σ-Δ modulators, and common-clock distribution across all four signal paths. This matching is characterized and guaranteed over −40°C to +125°C, making it suitable for beamforming in MIMO radar architectures.

Can the ADAR7251WBCSZ-RL be used without the integrated LNA and PGA stages?

Yes - the ADAR7251WBCSZ-RL allows bypassing of both LNA and PGA via register control, enabling direct connection of conditioned signals with full-scale differential input ranges from ±31 mV (45 dB gain) up to ±5.6 V (0 dB gain). This flexibility supports reuse in legacy signal chains or hybrid AFE designs with external gain blocks.

Is the ADAR7251WBCSZ-RL qualified for automotive applications and what safety features does it include?

Yes - the ADAR7251WBCSZ-RL is AEC-Q100 Grade 1 qualified (−40°C to +125°C) and includes ASIL-B-ready features: CRC-protected register map, dedicated fault output (FAULT pin), error masking registers, and ASIL error flag/code reporting. These enable integration into ISO 26262-compliant radar ECUs without external safety monitors.