Analog Devices Inc. AD7884BQ

Overview

AD7884BQ from Analog Devices is a 16-bit monolithic sampling analog-to-digital converter with internal sample-and-hold, 5.3 µs conversion time, ±0.0075% FSR integral nonlinearity, and ±5 V/±3 V dual input ranges - used in high-precision data acquisition systems requiring 166 kSPS throughput.

For engineers reviewing the AD7884BQ datasheet, AD7884BQ pinout, AD7884BQ application, or AD7884BQ equivalent, this page delivers verified electrical specs, package mapping to 40-lead CERDIP, functional pin roles, real-world use cases, and two confirmed alternative parts with documented technical differences.

Technical Context

The AD7884BQ implements a two-pass flash architecture: first pass captures 9 MSBs via a 9-bit ADC and feeds them to an on-chip 16-bit DAC; second pass digitizes the residue error amplified by an on-chip residue amplifier. Conversion is initiated asynchronously by CONVST and controlled by CS/RD logic interface.

It operates from ±5 V supplies with a 3 V reference (VREF+S), supports twos complement output coding, and integrates separate analog/digital ground paths (AGNDS/AGNDF, DGND) and power rails (AVDD/AVSS, VDD/VSS) to maintain DC accuracy and dynamic performance at 166 kSPS.

Key Specifications

Pinout & Package

AD7884BQ is housed in a hermetically sealed 40-lead CERDIP package (Q-40), rated for –40°C to +85°C operation, with lead finish suitable for wave soldering and compatible with MIL-STD-883 screening.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed 16-bit ADC applications.

Compared with AD7884BQ, AD7884BP offers identical functionality without guaranteed INL spec - reducing cost where calibration compensates; AD7884AP provides same performance in PLCC but requires PCB redesign and has higher thermal resistance.

Availability

AD7884BQ is available at Aetrix Electronics and suitable for automatic test equipment, medical instrumentation, and industrial control applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7884BQ 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 AD7884BQ belongs to Analog Devices' precision high-speed ADC product line, designed specifically for applications demanding 16-bit resolution, sub-microsecond conversion, and robust dc accuracy in harsh industrial environments.

FAQ

What is the operating temperature range for the AD7884BQ?

The AD7884BQ is specified for operation from –40°C to +85°C, consistent with its Industrial CERDIP (Q-40) packaging and B-grade performance binning. This range is validated across all key parameters including INL (±0.0075% FSR max), SNR (84 dB min), and conversion time (5.3 µs max). The device undergoes temperature cycling per MIL-STD-883 methods to ensure reliability in demanding industrial and medical deployments where ambient conditions exceed commercial-grade limits.

Does the AD7884BQ require an external clock source?

No, the AD7884BQ does not require an external clock source. It incorporates an internal oscillator that precisely governs the timing of both conversion phases - first pass (9-bit capture) and second pass (residue digitization). This eliminates clock distribution complexity and jitter sensitivity, enabling deterministic 5.3 µs conversion time and 166 kSPS throughput without external timing components. The internal oscillator is factory-trimmed and stable over temperature and supply voltage variations.

How is the ±3 V input range configured on the AD7884BQ?

To configure the ±3 V input range on the AD7884BQ, tie ±5VINF and ±5VINS to AGND, then drive ±3VINF and ±3VINS from the signal source. As shown in Figure 11 of the datasheet, this reconfigures the internal input scaling network to provide unity gain (–1×) for ±3 V inputs. The AD7884BQ's analog input section automatically adapts - no register writes or external switches are needed. The output code remains twos complement, with 1 LSB = 91.5 µV in this range.

What is the purpose of the AGNDS and AGNDF pins on the AD7884BQ?

The AGNDS (analog ground sense) and AGNDF (analog ground force) pins on the AD7884BQ form a Kelvin connection for the 9-bit ADC's ground reference. They must be driven by a low-offset, low-noise op amp (e.g., AD817) configured as a unity-gain buffer - with AGNDS connected to the amplifier output and AGNDF to its inverting input. This configuration maintains precise ground potential at the ADC core. Directly tying AGNDS/AGNDF together degrades INL, bipolar zero, and gain error by up to 3× compared to buffered operation.

Can the AD7884BQ be used with a single +5 V supply?

No, the AD7884BQ cannot operate from a single +5 V supply. It requires dual ±5 V analog supplies (AVDD = +5 V, AVSS = –5 V) and dual ±5 V digital supplies (VDD = +5 V, VSS = –5 V), as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. The analog input stage, sample-and-hold amplifier, and residue amplifier all depend on symmetric bipolar rails to handle ±5 V or ±3 V input signals. Attempting single-supply operation will result in immediate saturation, invalid conversions, and potential damage due to violation of VSS-to-AGND voltage limits.