Analog Devices Inc. AD7939BSUZ-REEL7

Overview

AD7939BSUZ-REEL7 from Analog Devices is a 10-bit, 8-channel, 1.5 MSPS successive approximation register (SAR) ADC with integrated channel sequencer, on-chip 2.5 V reference (±0.2% @ 25°C), and parallel interface supporting word/byte modes. It operates from a single 2.7 V to 5.25 V supply, consumes 6 mW at 3 V, and supports single-ended, pseudo-differential, or fully differential analog inputs - used in multichannel data acquisition systems for industrial process monitoring.

For engineers reviewing the AD7939BSUZ-REEL7 datasheet, AD7939BSUZ-REEL7 pinout, AD7939BSUZ-REEL7 application, or AD7939BSUZ-REEL7 equivalent, key selection criteria include its 10-bit resolution with ±0.5 LSB INL, 61 dB SINAD at 50 kHz, 1.5 MSPS throughput, software-configurable input types, and VDRIVE-enabled 3 V/5 V processor interfacing without level-shifting.

Technical Context

The AD7939BSUZ-REEL7 implements a SAR architecture with no pipeline delay, enabling deterministic conversion timing: conversion time is fixed at t₂ + 13 × t_CLKIN, initiated on the falling edge of CONVST. Its track-and-hold amplifier supports full-power bandwidth up to 50 MHz and handles 125 ns max acquisition time for full-scale steps.

It integrates a programmable sequencer that preselects up to eight channels for automatic sequential conversion, and an on-chip control register configuring input range (0–VREF or 0–2×VREF), output coding (straight binary or two's complement), power mode (normal/autostandby/shutdown), and interface behavior (word vs. byte mode via W/B and HBEN).

Key Specifications

Pinout & Package

AD7939BSUZ-REEL7 is housed in a 32-lead LFCSP (5 mm × 5 mm, CP-32-7), with exposed pad soldered to PCB ground plane for thermal and noise performance. Pin functions are validated per Analog Devices Rev. F datasheet Figures 2 and Table 6.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel SAR ADC applications.

Compared with AD7939BSUZ-REEL7, AD7938BSUZ-REEL7 offers 2 extra bits and 8 dB better SINAD at the cost of +7.5 mW power and tighter layout sensitivity, while ADS8688IPWR trades parallel speed and sequencer automation for higher resolution and simpler serial interfacing - making each suitable for distinct trade-off priorities in DAQ architecture.

Availability

AD7939BSUZ-REEL7 is available at Aetrix Electronics and suitable for industrial process monitoring, motor control feedback, power quality analysis, and test & measurement equipment requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AD7939BSUZ-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, serving industrial, automotive, communications, and healthcare markets.

The AD793x family targets high-speed, low-power, multichannel data acquisition systems where deterministic timing, flexible input configuration, and integrated reference stability are essential - especially in space- and power-constrained industrial controllers.

FAQ

What is the maximum sample rate supported by the AD7939BSUZ-REEL7?

The AD7939BSUZ-REEL7 supports a maximum throughput rate of 1.5 MSPS, achieved with a 25.5 MHz master clock (CLKIN) and fixed 13-clock-cycle conversion time. This rate is maintained across its full operating temperature range (−40°C to +85°C) and supply range (2.7 V to 5.25 V), with no performance derating.

Does the AD7939BSUZ-REEL7 require an external reference voltage?

No, the AD7939BSUZ-REEL7 includes an accurate on-chip 2.5 V reference (±0.2% @ 25°C, 25 ppm/°C) available at the VREFIN/VREFOUT pin. However, it can be overdriven with an external reference from 0.1 V to VDD if system-level accuracy or custom full-scale range requirements demand it.

How does the AD7939BSUZ-REEL7 handle channel sequencing?

The AD7939BSUZ-REEL7 features an integrated hardware sequencer programmed via its control register. Users define a sequence of up to eight channels (VIN0–VIN7), and the device automatically converts them in order upon consecutive CONVST triggers - eliminating host CPU polling or software loop overhead.

What is the function of the VDRIVE pin on the AD7939BSUZ-REEL7?

The VDRIVE pin on the AD7939BSUZ-REEL7 sets the logic voltage threshold for all parallel interface pins (DB0–DB11, RD, WR, CS, etc.). It may be driven at 3 V or 5 V independently of VDD, enabling direct interfacing with mixed-voltage microcontrollers without external level shifters - a key design simplification in heterogeneous systems.

Can the AD7939BSUZ-REEL7 operate in low-power modes?

Yes, the AD7939BSUZ-REEL7 supports three power modes: normal (2.7 mA max @ 5 V), autostandby (160 µA typ @ 100 kSPS), and full shutdown (2 µA max). These are controlled via the on-chip control register and reduce power proportionally to sampling activity - critical for battery-powered or thermally constrained DAQ systems.