Analog Devices Inc. AD976AN

Overview

AD976AN from Analog Devices is a 16-bit, 100 kSPS BiCMOS successive-approximation analog-to-digital converter (ADC) with ±10 V bipolar input range, internal 2.5 V reference, and parallel 16-bit twos-complement output interface. It operates from a single +5 V supply, dissipates ≤100 mW, and targets precision data acquisition in industrial instrumentation and automated test equipment.

For engineers reviewing the AD976AN datasheet, AD976AN pinout, AD976AN application, or AD976AN equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative options - all grounded in Analog Devices' official AD976/AD976A Rev. D documentation and ordering guide.

Technical Context

The AD976AN implements a switched-capacitor SAR architecture with on-chip laser-trimmed capacitor array calibration, eliminating external sample-and-hold circuitry and minimizing temperature-induced linearity drift. Its factory-calibrated offset and gain correction uses stored coefficients in thin-film resistors acting as ROM.

It supports dual reference modes: internal 2.5 V reference (±0.2% initial accuracy, ±7 ppm/°C drift) or external reference (2.3–2.7 V), with dedicated REF and CAP pins for decoupling. The parallel interface features BYTE-selectable 16-bit or split-byte output timing synchronized to R/C and CS control signals.

Key Specifications

Pinout & Package

AD976AN is housed in a 28-lead, 300-mil plastic DIP (package code N-28B), with separate analog (AGND1, AGND2) and digital (DGND) ground pins to minimize noise coupling. Pin 1 is VIN; pin 28 is VDIG.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD976AN, AD974AN trades 2 bits of resolution and reference integration for lower cost and identical form factor, while ADS8505IPW offers higher speed and modern packaging at the expense of increased power and loss of internal reference - making AD976AN optimal for legacy-compatible, self-contained 16-bit industrial DAQ.

Availability

AD976AN is available at Aetrix Electronics and suitable for industrial data acquisition, automated test equipment, scientific instrumentation, and energy metering calibration requiring stable component supply and long-term obsolescence management.

Supply support for AD976AN 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 Wilmington, MA.

The AD976 family was designed specifically for high-accuracy, single-supply, 16-bit data acquisition in industrial and instrumentation systems - emphasizing factory-calibrated linearity, integrated reference, and robust noise immunity.

FAQ

What is the maximum sampling rate supported by the AD976AN?

The AD976AN supports a maximum throughput rate of 100 kSPS, corresponding to a 10 µs conversion cycle time. This is confirmed in the AD976–SPECIFICATIONS table (Rev. D, page 3), where "Throughput Rate" is specified as 100 kHz for all grades. The AD976A variant achieves 200 kSPS, but AD976AN is strictly rated at 100 kSPS.

Does the AD976AN require an external reference voltage?

No, the AD976AN does not require an external reference voltage. It integrates a factory-calibrated 2.5 V internal reference (2.48 V to 2.52 V) with ±7 ppm/°C drift, as specified in the REFERENCE section of the AD976–SPECIFICATIONS table. An external reference (2.3–2.7 V) may be used optionally, but the internal reference is fully functional and eliminates BOM cost.

What package type is used for the AD976AN?

The AD976AN uses a 28-lead, 300-mil plastic DIP package (ordering code N-28B), as explicitly stated in the ORDERING GUIDE (Rev. D, page 5). This through-hole package is distinct from SOIC (R-28) and SSOP (RS-28) variants offered for other AD976/AD976A models.

How is the analog input range configured on the AD976AN?

The AD976AN is factory-configured for a ±10 V bipolar analog input range, achieved using laser-trimmed scaling resistors. As documented in the GENERAL DESCRIPTION and ANALOG INPUT section, this range is expressed as ±4 × VREF - so with the internal 2.5 V reference, full-scale equals ±10 V. No configuration pins or registers are needed to set this range.

What digital interface protocol does the AD976AN use?

The AD976AN uses a high-speed parallel interface with Binary Twos Complement data format, controlled by R/C (Read/Convert), CS (Chip Select), and BYTE signals. Timing is defined by BUSY status and supports both full 16-bit and split-byte read modes - not SPI, I²C, or serial protocols. This is confirmed in the FUNCTIONAL BLOCK DIAGRAM, PIN FUNCTION DESCRIPTIONS, and TIMING SPECIFICATIONS.