Analog Devices Inc. AD7933BRU-REEL

Overview

AD7933BRU-REEL from Analog Devices is a 10-bit, 4-channel, 1.5 MSPS successive approximation register (SAR) analog-to-digital converter with integrated channel sequencer and on-chip 2.5 V reference. It operates from a single 2.7 V to 5.25 V supply, supports single-ended/pseudo-differential/differential input configurations via software control, and delivers 61 dB SINAD at 50 kHz input frequency in differential mode. It targets high-speed data acquisition in industrial process control systems requiring multi-channel synchronized sampling.

For engineers reviewing the AD7933BRU-REEL datasheet, AD7933BRU-REEL pinout, AD7933BRU-REEL application, or AD7933BRU-REEL equivalent, key selection considerations include its 10-bit resolution with ±0.5 LSB INL, 28-lead TSSOP package, parallel word/byte interface with VDRIVE voltage independence, no pipeline delay, and sequencer-driven 4-channel conversion sequencing without external logic.

Technical Context

The AD7933BRU-REEL implements a SAR architecture with a differential track-and-hold amplifier supporting up to 50 MHz input bandwidth and 125 ns acquisition time. Its sequencer enables preprogrammed channel selection across VIN0–VIN3, configurable as four single-ended, two fully differential, or two pseudo-differential inputs using MODE bits in the control register.

Conversion is initiated by the falling edge of CONVST, with timing governed by a 25.5 MHz master clock (CLKIN); total conversion time is t₂ + 13 t_CLK. The device uses an accurate internal 2.5 V reference (±0.2% @ 25°C, 25 ppm/°C), which can be overdriven by an external reference between 0.1 V and VDD.

Key Specifications

Pinout & Package

AD7933BRU-REEL is housed in a 28-lead thin shrink small outline package (TSSOP), optimized for compact PCB layouts and thermal performance (θ_JA = 97.9°C/W). Pin functions are validated per Analog Devices Rev. B datasheet Figure 2 and Table 6.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7934BRU-REEL and AD7938BRU-REEL, AD7933BRU-REEL delivers the lowest power consumption and smallest footprint for 4-channel, 10-bit applications-making it the preferred choice for space-constrained, battery-operated, or thermally sensitive industrial data acquisition systems.

Availability

AD7933BRU-REEL is available at Aetrix Electronics and suitable for industrial process monitoring, motor drive current sensing, portable power quality analyzers, and multi-sensor environmental data loggers requiring stable component supply and long-term production continuity.

Supply support for AD7933BRU-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7933BRU-REEL belongs to Analog Devices' precision SAR ADC product line, designed specifically for high-speed, multi-channel data acquisition in industrial automation, energy metering, and test equipment where accuracy, low power, and deterministic timing are critical.

FAQ

What is the maximum sampling rate supported by the AD7933BRU-REEL?

The AD7933BRU-REEL supports a maximum throughput rate of 1.5 MSPS, achieved with a 25.5 MHz master clock (CLKIN) and conversion time of t₂ + 13 t_CLK. This rate is maintained across all input configurations (single-ended, pseudo-differential, or fully differential) and supply voltages from 2.7 V to 5.25 V. At lower clock frequencies, throughput scales linearly, but dynamic specifications such as SINAD apply only at the rated 1.5 MSPS condition.

Does the AD7933BRU-REEL require an external reference voltage?

No, the AD7933BRU-REEL includes an accurate on-chip 2.5 V reference with ±0.2% initial accuracy at 25°C and 25 ppm/°C temperature coefficient, sufficient for most industrial applications. However, the VREFIN/VREFOUT pin can be overdriven with an external reference from 0.1 V to VDD if higher precision or custom voltage scaling is required. Using the internal reference eliminates BOM cost and layout complexity associated with external references.

How does the channel sequencer in the AD7933BRU-REEL operate?

The AD7933BRU-REEL's hardware sequencer automatically cycles through VIN0–VIN3 based on preprogrammed settings in the control register's SEQ bits. It supports sequential, ping-pong, or single-channel repeat modes without CPU intervention. Channel selection is synchronized to CONVST edges, ensuring deterministic timing and eliminating software-induced jitter. The sequencer retains state during autostandby, enabling rapid resumption of acquisition after wake-up.

Can the AD7933BRU-REEL interface directly with a 3 V microcontroller while operating from a 5 V supply?

Yes, the AD7933BRU-REEL's VDRIVE pin allows independent configuration of the parallel interface voltage. When VDRIVE = 3 V and VDD = 5 V, the DB0–DB11, RD, WR, CS, and BUSY signals operate at 3 V logic levels - enabling direct, glueless connection to 3 V microcontrollers or FPGAs without level shifters. This separation simplifies mixed-voltage system design and improves noise immunity on digital lines.

What are the absolute maximum ratings for analog input voltage on the AD7933BRU-REEL?

The absolute maximum analog input voltage for the AD7933BRU-REEL is −0.3 V to VDD + 0.3 V relative to AGND, per Table 5 of the datasheet. Exceeding this range risks permanent damage. For safe operation within specifications, the input must remain within 0 to VREF or 0 to 2×VREF (configurable via RANGE bit), and VIN− in pseudo-differential mode must stay between −0.3 V and +1.8 V (at VDD = 5 V). Proper decoupling and input protection circuitry are recommended for transient-prone environments.