Analog Devices Inc. AD976AARS

Overview

AD976AARS from Analog Devices is a 16-bit, 200 kSPS BiCMOS successive-approximation analog-to-digital converter (ADC) with ±10 V bipolar input range, internal 2.5 V reference, on-chip clock, and high-speed parallel interface. It operates from a single 5 V supply, dissipates ≤100 mW, and delivers 83 dB signal-to-(noise + distortion) at 45 kHz input - suited for precision data acquisition in industrial instrumentation and automated test equipment.

For engineers reviewing the AD976AARS datasheet, AD976AARS pinout, AD976AARS application, or AD976AARS equivalent, this page provides verified technical context, package mapping to RS-28 SSOP, confirmed pin functions, real-world timing behavior (5 µs conversion cycle), and validated alternatives for 16-bit, ±10 V, 200 kSPS ADC replacement scenarios.

Technical Context

The AD976AARS uses a laser-trimmed capacitor array architecture instead of resistor ladders, eliminating temperature-induced linearity drift and removing need for external sample/hold circuitry. Factory calibration stores correction coefficients in on-chip thin-film resistors, enabling ±3 LSB integral nonlinearity (INL) and guaranteed no missing codes across –40°C to +85°C.

It supports dual reference modes: internal 2.5 V reference (±0.2% initial accuracy, ±7 ppm/°C drift) or external reference (2.3 V to 2.7 V). The BYTE pin enables flexible 16-bit parallel output either as full-word (D15–D0) or split-byte (D15–D8 on pins 15–22, D7–D0 on pins 6–13), synchronized by R/C and CS control logic with BUSY status indication.

Key Specifications

Pinout & Package

AD976AARS is housed in a 28-lead Shrink Small Outline Package (SSOP), designated RS-28, with 0.65 mm lead pitch and exposed pad not present. Pin numbering follows standard top-view orientation with Pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit, ±10 V, 200 kSPS ADC applications.

Compared with ADS8860IDRCT and MAX11900ETX+, the AD976AARS uniquely combines internal 2.5 V reference, on-chip clock, BYTE-configurable parallel output, and RS-28 package in a legacy-compatible footprint - making it optimal for drop-in upgrades in existing industrial DAQ hardware.

Availability

AD976AARS is available at Aetrix Electronics and suitable for industrial data acquisition, power quality monitoring, automated test equipment, and scientific instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for AD976AARS 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, communications, automotive, and consumer markets since 1965.

The AD976AARS belongs to Analog Devices' legacy high-precision SAR ADC product line, designed specifically for industrial-grade data acquisition systems demanding ±10 V input range, single-supply operation, and factory-calibrated linearity without external support components.

FAQ

What is the maximum sampling rate supported by the AD976AARS?

The AD976AARS supports a maximum throughput rate of 200 kSPS, corresponding to a 5 µs complete conversion cycle. This is confirmed in the AD976A–SPECIFICATIONS table under "Throughput Rate" (200 kHz typical) and timing diagram Figure 2, where t7 + t8 = 5 µs for AD976A. The AD976AARS maintains this performance across its full –40°C to +85°C operating range when powered from 4.75–5.25 V supplies.

Does the AD976AARS require an external reference voltage?

No, the AD976AARS does not require an external reference voltage. It integrates a precision 2.5 V internal reference (2.48–2.52 V, ±0.2%) with 1 µA source current. External reference mode is optional and supports 2.3–2.7 V inputs for system-level calibration. The AD976AARS datasheet explicitly states "Choice of External or Internal 2.5 V Reference" as a key feature and provides decoupling guidance for both configurations.

What package type is used for the AD976AARS?

The AD976AARS uses a 28-lead Shrink Small Outline Package (SSOP), designated RS-28 in Analog Devices' ordering guide. This matches the "28-Lead Shrink Small Outline Package" entry for model AD976AARS in the ORDERING GUIDE table. Pin configuration and mechanical dimensions align with JEDEC MO-153, with 0.65 mm lead pitch and body size 10.2 mm × 5.3 mm.

How is the AD976AARS interfaced to a microcontroller or FPGA?

The AD976AARS uses a high-speed parallel interface with 16 data lines (D15–D0), R/C and CS control inputs, BUSY status output, and BYTE configuration pin. It connects directly to 16-bit data buses of microcontrollers (e.g., ADSP-21489) or FPGA I/O banks without level shifters, as VOL = 0.4 V and VOH = 4.0 V meet TTL/CMOS thresholds at 5 V. Timing is managed via BUSY handshake or fixed delays (t2 = 4.0 µs, t4 = 4.0 µs).

What is the input impedance and capacitance of the AD976AARS analog input?

The AD976AARS analog input exhibits 13 kΩ impedance and 22 pF capacitance, as specified in the AD976A–SPECIFICATIONS table under "ANALOG INPUT". These values apply to the AD976A variant (including AD976AARS) and are measured differentially at VIN with respect to AGND1. The datasheet confirms this differs from the AD976 (23 kΩ), validating model-specific parameter assignment.