Analog Devices Inc. AD7738BRUZ-REEL7

Overview

AD7738BRUZ-REEL7 from Analog Devices is a high-precision, 24-bit sigma-delta analog-to-digital converter with eight single-ended or four fully differential input channels, 0.0015% integral nonlinearity, 18-bit p-p resolution at 500 Hz, and on-chip per-channel system calibration. It operates from a 5 V analog supply and 3 V/5 V digital supply in industrial temperature range (–40°C to +105°C), targeting multiplexed process control instrumentation.

For engineers reviewing the AD7738BRUZ-REEL7 datasheet, AD7738BRUZ-REEL7 pinout, AD7738BRUZ-REEL7 application, or AD7738BRUZ-REEL7 equivalent, this page delivers verified technical context, real-world resolution trade-offs across chopping modes, validated serial interface timing for SPI/QSPI/MICROWIRE, and confirmed package-level thermal and layout constraints for TSSOP-28 deployment.

Technical Context

The AD7738BRUZ-REEL7 implements a sigma-delta modulator with programmable filter word (FW = 0x02 to 0xFF), enabling conversion rates from 372 Hz (chopping enabled) to 15.4 kHz (chopping disabled). Its multiplexer output (MUXOUT±) is externally accessible, allowing pre-ADC signal conditioning or gain staging before ADCIN±.

It supports dual-supply operation (AVDD = 5 V, DVDD = 3 V or 5 V), features Schmitt-triggered logic inputs, integrated "No-Reference" detection on REFIN±, and configurable input ranges (±2.5 V, ±1.25 V, ±625 mV, or unipolar equivalents). Calibration is performed per channel via dedicated ZS/FS registers.

Key Specifications

Pinout & Package

AD7738BRUZ-REEL7 is housed in a 28-lead Thin Shrink Small Outline Package (TSSOP), RoHS-compliant, with exposed pad not electrically connected. Pin pitch is 0.65 mm; body dimensions are 9.7 mm × 4.4 mm × 1.1 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7734BRUZ and AD7172-2BRUZ, the AD7738BRUZ-REEL7 uniquely balances 8-channel density, external MUXOUT accessibility, and on-chip per-channel calibration - making it optimal for space-constrained, multi-sensor industrial modules requiring field-trimmable accuracy without layout changes.

Availability

AD7738BRUZ-REEL7 is available at Aetrix Electronics and suitable for PLC analog input modules, multiplexed sensor data loggers, and industrial process controllers requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant TSSOP packaging.

Supply support for AD7738BRUZ-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7738BRUZ-REEL7 belongs to Analog Devices' precision sigma-delta ADC family designed specifically for high-accuracy, multiplexed industrial measurement systems where channel density, calibration flexibility, and robust serial interfacing are critical.

FAQ

What is the maximum channel switching rate of the AD7738BRUZ-REEL7 with 18-bit p-p resolution?

The AD7738BRUZ-REEL7 achieves 18-bit p-p resolution at 500 Hz channel switching rate when chopping is enabled (FW = 0xFF, conversion time = 2686 µs). This corresponds to a total conversion time of 2.686 ms per channel, supporting synchronized sampling across all 8 inputs in under 21.5 ms - sufficient for sub-50 Hz anti-aliasing in vibration monitoring applications.

Does the AD7738BRUZ-REEL7 support true bipolar input ranges?

Yes, the AD7738BRUZ-REEL7 supports true bipolar input ranges including ±2.5 V, ±1.25 V, and ±625 mV, as confirmed in Table IX and the General Description. These ranges allow direct digitization of AC-coupled or center-zero sensor outputs without external level-shifting circuitry - a key capability distinguishing it from unipolar-only ADCs.

How does the MUXOUT feature of the AD7738BRUZ-REEL7 improve system design flexibility?

The MUXOUT(+) and MUXOUT(–) pins on the AD7738BRUZ-REEL7 expose the analog signal after channel selection but before the ADC core. This allows insertion of external programmable gain stages, anti-alias filters, or isolation amplifiers without modifying the ADC's internal signal path - enabling one PCB layout to support multiple sensor types via firmware configuration alone.

Can the AD7738BRUZ-REEL7 operate with a 3 V digital supply while using a 5 V analog supply?

Yes, the AD7738BRUZ-REEL7 explicitly supports mixed-supply operation: AVDD = 4.75–5.25 V and DVDD = 2.7–3.6 V (or 4.75–5.25 V). The datasheet specifies 1.0–1.5 mA DVDD current at 3 V, confirming robust functionality in 3 V microcontroller domains interfaced to 5 V sensor front ends - a common architecture in isolated industrial I/O designs.

What calibration capabilities does the AD7738BRUZ-REEL7 provide beyond factory trimming?

The AD7738BRUZ-REEL7 provides per-channel zero-scale and full-scale system calibration via dedicated 24-bit registers (addresses 0x10–0x17 and 0x18–0x1F). Unlike one-time factory calibration, these registers allow field recalibration against known references - correcting for PCB-level drift, connector resistance, or sensor aging without hardware intervention or re-spinning the board.