Analog Devices Inc. AD7961BCPZ-RL7

Overview

AD7961BCPZ-RL7 from Analog Devices is a 16-bit, 5 MSPS charge redistribution successive approximation register (SAR) analog-to-digital converter with true differential input, ±4.096 V or ±5 V input range, 95.5 dB SNR, and LVDS serial interface. It operates across −40°C to +85°C and delivers no missing codes with ±0.55 LSB max INL - deployed in high-speed digital X-ray and MRI gradient control systems where latency-free sampling and dc precision are critical.

For engineers reviewing the AD7961BCPZ-RL7 datasheet, AD7961BCPZ-RL7 pinout, AD7961BCPZ-RL7 application, or AD7961BCPZ-RL7 equivalent, key selection criteria include its 5 MSPS throughput with zero pipeline delay, self-clocked or echoed clock LVDS interface timing, differential input common-mode range alignment with VCM output, and internal reference buffer configurability for ±4.096 V or ±5 V full-scale operation.

Technical Context

The AD7961BCPZ-RL7 implements a charge redistribution SAR architecture with dual 16-bit capacitive DAC arrays, enabling simultaneous acquisition on IN+ and IN− with antiphase voltage swings. Its conversion is triggered on the CNV± edge, and all 16-bit results are serialized via LVDS outputs (D+, D−) synchronized to either internal self-clocking or externally echoed CLK±.

It supports two digital interface modes: self-clocked (DCO+ grounded) with 18-bit frame format (2-bit header + 16 data bits), and echoed clock (DCO± = CLK±) with 16-bit LSB-aligned output. The VCM pin provides a precise REF/2 common-mode voltage, while EN0–EN3 configure reference buffer enablement, input bandwidth (9 MHz or 28 MHz), and VCM output activation.

Key Specifications

Pinout & Package

AD7961BCPZ-RL7 is housed in a 32-lead, 5 mm × 5 mm LFCSP (QFN) package with exposed pad (EP) for thermal management. Pin assignments follow the standard Analog Devices LFCSP_VQ footprint with dual power domains (VDD1/VDD2/VIO) and dedicated reference ground (REF_GND).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, high-precision SAR ADC applications.

Compared with AD7961BCPZ-RL7, AD7960BCPZ-RL7 trades reference flexibility for 2 extra bits of resolution, while AD7626BCPZ-RL7 sacrifices differential input integrity and serial noise immunity to achieve double the throughput - making AD7961BCPZ-RL7 the optimal balance of speed, precision, interface robustness, and design simplicity for medical imaging front ends.

Availability

AD7961BCPZ-RL7 is available at Aetrix Electronics and suitable for digital X-ray imaging, computed tomography, and MRI gradient control systems requiring stable component supply, long-term lifecycle support, and traceable sourcing for Class II medical device manufacturing.

Supply support for AD7961BCPZ-RL7 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 decades of expertise in precision data conversion and signal conditioning.

The AD7961 belongs to Analog Devices' PulSAR® family of high-speed SAR ADCs, designed specifically for demanding medical imaging, scientific instrumentation, and automated test equipment where speed, linearity, and low latency are non-negotiable.

FAQ

What is the maximum sample rate supported by the AD7961BCPZ-RL7?

The AD7961BCPZ-RL7 supports a maximum throughput rate of 5 MSPS (5 million samples per second), with a minimum conversion cycle time of 200 ns. This rate is achievable in both self-clocked and echoed clock LVDS interface modes, and is fully characterized across the −40°C to +85°C operating temperature range. The AD7961BCPZ-RL7 maintains its 16-bit no-missing-codes performance and 95.5 dB SNR at this full rate.

Does the AD7961BCPZ-RL7 require an external reference voltage?

The AD7961BCPZ-RL7 supports both external and internally buffered reference configurations. It can accept a direct 4.096 V or 5 V reference on the REF pin, or use a 2.048 V source on REFIN to enable the internal reference buffer that generates 4.096 V at REF. The AD7961BCPZ-RL7 does not require an external reference when the internal buffer is enabled and properly decoupled.

What interface standards does the AD7961BCPZ-RL7 support for digital output?

The AD7961BCPZ-RL7 features a serial LVDS interface compliant with ANSI-644, delivering 16-bit twos-complement data on D+ and D− pins. It operates in either self-clocked mode (DCO+ grounded, 18-bit frame with 2-bit sync header) or echoed clock mode (DCO± mirrors CLK±, 16-bit LSB-aligned). It does not support SPI, I²C, or parallel CMOS interfaces.

How is the common-mode voltage handled on the AD7961BCPZ-RL7 analog inputs?

The AD7961BCPZ-RL7 provides a dedicated VCM pin that outputs a precise REF/2 voltage, intended to drive the common-mode node of external differential drivers. Its common-mode input range is tightly specified as VREF/2 ± 50 mV, and the VCM output error is limited to ±0.01 V - ensuring accurate biasing and maximizing CMRR without external components.

What package type and thermal characteristics apply to the AD7961BCPZ-RL7?

The AD7961BCPZ-RL7 is supplied in a 32-lead, 5 mm × 5 mm LFCSP_VQ package with exposed pad (EP), offering θJA = 40°C/W and θJC = 4°C/W. The EP must be soldered to the PCB ground plane using multiple thermal vias. This package enables compact layout in high-density medical imaging modules while maintaining thermal performance under continuous 5 MSPS operation.