Analog Devices Inc. AD7734BRUZ-REEL7

Overview

AD7734BRUZ-REEL7 from Analog Devices is a 24-bit sigma-delta analog-to-digital converter with four single-ended input channels, ±10 V input range, 21-bit effective resolution at 500 Hz, on-chip per-channel system calibration, and 3-wire SPI-compatible serial interface. It operates from a single 5 V analog supply and supports industrial process control signal acquisition.

For engineers reviewing the AD7734BRUZ-REEL7 datasheet, AD7734BRUZ-REEL7 pinout, AD7734BRUZ-REEL7 application, or AD7734BRUZ-REEL7 equivalent, key selection considerations include channel switching time (500 µs at 2 kHz), ±0.0025% INL, overvoltage tolerance up to ±16.5 V without adjacent channel crosstalk, and TSSOP-28 package compatibility with high-density industrial PCB layouts.

Technical Context

The AD7734BRUZ-REEL7 implements a fourth-order sigma-delta modulator with digital filtering optimized for fast multiplexed channel switching. Its architecture supports independent conversion timing per channel via programmable filter word (FW) register settings, enabling trade-offs between noise performance and throughput from 372 Hz to 15.4 kHz.

It integrates an analog front end with internal bias networks (BIAS0–BIAS3, BIASHI, BIASLO), overrange/underrange detection, and "No-Reference" detect logic on REFIN(±). The device uses Schmitt-triggered digital inputs and supports both chopping-enabled (low drift) and chopping-disabled (high speed) operation modes with distinct noise/resolution profiles.

Key Specifications

Pinout & Package

AD7734BRUZ-REEL7 is housed in a 28-lead TSSOP package (4.4 mm × 9.7 mm, 0.65 mm pitch), optimized for automated assembly and thermal performance in industrial enclosures.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-resolution multiplexed ADC applications.

Compared with AD7734BRUZ-REEL7, AD7732BRUZ reduces channel count but retains identical noise performance and calibration architecture, while AD7738BRUZ expands flexibility at the cost of board area and external component dependency for high-voltage signal chains.

Availability

AD7734BRUZ-REEL7 is available at Aetrix Electronics and suitable for PLC/DCS modules, industrial instrumentation, and process control systems requiring stable component supply across extended temperature and long product lifecycles.

Supply support for AD7734BRUZ-REEL7 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7734BRUZ-REEL7 belongs to Analog Devices' precision sigma-delta ADC family designed specifically for high-accuracy, multiplexed industrial data acquisition where channel density, noise immunity, and field calibration are critical.

FAQ

What is the maximum input voltage the AD7734BRUZ-REEL7 can tolerate without damaging the device?

The AD7734BRUZ-REEL7 has an absolute maximum AIN-to-AGND rating of ±50 V per the datasheet Absolute Maximum Ratings table. However, for guaranteed non-degrading operation-i.e., no impact on adjacent channel accuracy-the device tolerates up to ±16.5 V on any single input while maintaining >110 dB channel-to-channel isolation. Operation beyond ±10 V nominal range sets the OVR bit in the channel status register.

Does the AD7734BRUZ-REEL7 require an external reference voltage?

Yes, the AD7734BRUZ-REEL7 requires an external differential reference applied to REFIN(+) and REFIN(–) pins. The specified range is 2.475 V to 2.525 V for full accuracy, though the device remains functional at lower voltages. It includes "No-Reference" detect logic that asserts the NOREF bit in the channel status register if reference voltage falls below 0.5 V, enabling fail-safe system response.

Can the AD7734BRUZ-REEL7 perform simultaneous sampling across all four channels?

No, the AD7734BRUZ-REEL7 does not support true simultaneous sampling. It uses a single sigma-delta modulator with an internal multiplexer to sequentially sample AIN0–AIN3. The fastest channel-switching rate is 2 kHz (500 µs per channel), and conversion timing is independently configurable per channel via the Channel Conversion Time Register, enabling staggered or synchronized sequential acquisition.

What digital interface protocols does the AD7734BRUZ-REEL7 support?

The AD7734BRUZ-REEL7 supports 3-wire serial communication compatible with SPI, QSPI™, MICROWIRE, and DSP interfaces. It uses SCLK, DIN, and DOUT lines with active-low CS for multi-device bus sharing. All digital inputs feature Schmitt triggers with defined VT+ and VT− thresholds (e.g., 0.8 V to 3.5 V for DVDD = 5 V), ensuring reliable operation in electrically noisy industrial environments.

How does the AD7734BRUZ-REEL7 handle calibration in the field?

The AD7734BRUZ-REEL7 supports per-channel system calibration using dedicated Channel Zero-Scale and Channel Full-Scale Calibration Registers. Users apply known zero-scale and full-scale analog inputs to each channel individually, then write resulting values to these registers. This corrects gain/offset errors down to the noise floor-reducing initial ±0.0025% INL and ±15 mV offset to residual errors dominated by rms noise rather than systematic error.