Analog Devices Inc. AD7732BRUZ-REEL

Overview

AD7732BRUZ-REEL from Analog Devices is a 24-bit sigma-delta analog-to-digital converter with two fully differential input channels, ±10 V input range, 18-bit peak-to-peak resolution at 500 Hz, on-chip per-channel system calibration, and 3-wire SPI-compatible serial interface - used in high-precision industrial multiplexed data acquisition systems.

For engineers reviewing the AD7732BRUZ-REEL datasheet, AD7732BRUZ-REEL pinout, AD7732BRUZ-REEL application, or AD7732BRUZ-REEL equivalent, key selection criteria include channel isolation (110 dB), chopping-enabled offset drift (±2.5 µV/°C), conversion time programmability (372–12,190 Hz), overvoltage tolerance (±16.5 V without adjacent channel degradation), and TSSOP-28 package compatibility with industrial temperature operation (–40°C to +105°C).

Technical Context

The AD7732BRUZ-REEL implements a 24-bit sigma-delta modulator with digital filter, configurable filter word (FW = 2–127), and dual-channel multiplexer enabling fast channel switching (500 µs total conversion time at 2 kHz). It supports independent per-channel zero-scale and full-scale calibration registers and features "No-Reference" detect logic on REFIN(±).

Its analog front end accepts true bipolar or unipolar inputs up to ±10 V while operating from a single 5 V analog supply (AVDD), with digital I/O compatible with 3 V or 5 V DVDD. Input overvoltage tolerance extends to ±16.5 V without performance impact on adjacent channels, and absolute maximum AIN voltage is ±50 V.

Key Specifications

Pinout & Package

Package: 28-lead TSSOP (RoHS-compliant, moisture sensitivity level 3, rated for –40°C to +105°C operation).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision, multi-channel sigma-delta ADC applications.

Compared with AD7732BRUZ-REEL, AD7734BRUZ trades differential input integrity and per-channel calibration for higher channel count in single-ended mode, while AD7738BRUZ adds architectural flexibility at the cost of increased complexity and different input voltage scaling - neither offers pin compatibility or identical register mapping.

Availability

AD7732BRUZ-REEL is available at Aetrix Electronics and suitable for PLC analog input modules, multiplexed sensor hubs, process controller ADC subsystems, high-accuracy data loggers, and industrial instrumentation requiring stable component supply across extended temperature and long product lifecycles.

Supply support for AD7732BRUZ-REEL 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design and manufacturing operations worldwide.

The AD7732BRUZ-REEL belongs to Analog Devices' high-precision sigma-delta ADC product line, engineered specifically for industrial process control, automated test equipment, and high-channel-count data acquisition where resolution, channel isolation, and robustness under electrical stress are critical.

FAQ

What is the maximum analog input voltage the AD7732BRUZ-REEL can tolerate without damage?

The AD7732BRUZ-REEL has an absolute maximum AIN-to-AGND rating of ±50 V per the datasheet Absolute Maximum Ratings table. However, for guaranteed non-degrading operation - especially regarding adjacent channel isolation - input voltages must remain within ±16.5 V. Exceeding ±16.5 V may preserve functionality but risks reduced channel-to-channel isolation and potential long-term reliability impact. Always refer to Table 3 and Figure 27 in the AD7732BRUZ-REEL datasheet for safe operating area boundaries.

Does the AD7732BRUZ-REEL support true bipolar input ranges?

Yes, the AD7732BRUZ-REEL supports true bipolar differential input ranges including ±10 V and ±5 V, as explicitly stated in the General Description and Specifications tables. This capability allows direct digitization of signals centered around 0 V - such as bridge sensor outputs or bipolar process signals - without external level-shifting circuitry. The analog front end operates from a single +5 V AVDD supply while maintaining full bipolar range performance.

How does chopping affect the performance of the AD7732BRUZ-REEL?

Enabling chopping (CHOP = 1) in the AD7732BRUZ-REEL reduces offset drift to ±2.5 µV/°C and improves integral nonlinearity to ±0.0003% FSR, at the expense of maximum output data rate (372–12,190 Hz). Disabling chopping (CHOP = 0) increases conversion speed - up to 15.4 kHz - while relaxing offset drift to ±25 µV/°C. The choice depends on whether thermal stability or throughput dominates the application's requirements.

Can the AD7732BRUZ-REEL operate with a 3 V digital supply while using 5 V for analog circuits?

Yes, the AD7732BRUZ-REEL supports independent digital and analog supplies: DVDD may be 2.7–3.6 V or 4.75–5.25 V, while AVDD is strictly 4.75–5.25 V. When DVDD = 3 V, digital I/O thresholds adjust accordingly (e.g., VINH = 2.5 V), and DVDD current drops to 1.0–1.5 mA. This dual-supply flexibility enables low-power microcontroller interfacing without level shifters, preserving noise separation between analog and digital domains.

What is the purpose of the RDY pin on the AD7732BRUZ-REEL?

RDY is an open-drain output that goes low when valid conversion data is ready in the channel data register. It serves as a hardware handshake signal for interrupt-driven or polled data acquisition, eliminating the need for continuous status register reads. In systems with tight timing constraints - such as real-time PLC scan cycles - RDY enables deterministic latency between conversion completion and data read, improving system predictability and reducing CPU overhead. Its behavior is unaffected by CS or SCLK state.