Analog Devices Inc. AD976AAR

Overview

AD976AAR from Analog Devices is a 16-bit, 200 kSPS BiCMOS successive-approximation analog-to-digital converter (ADC) with ±10 V 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 AD976AAR datasheet, AD976AAR pinout, AD976AAR application, or AD976AAR equivalent, this page provides verified functional identity, package-mapped pin roles, real-world timing behavior, confirmed AC/DC accuracy specs per grade, and validated alternatives for ±10 V, 200 kSPS sampling systems requiring factory-calibrated linearity and low-power single-supply operation.

Technical Context

The AD976AAR implements a switched-capacitor SAR architecture with laser-trimmed scaling resistors and on-chip capacitor-array charge redistribution - eliminating external sample-and-hold circuitry and minimizing temperature-induced linearity drift. Calibration coefficients are stored in thin-film ROM and applied dynamically during conversion to correct capacitor mismatches and offset errors.

It supports dual-mode digital control via R/C and CS inputs: either R/C-triggered conversion with CS held low (Figure 2), or CS-gated read/conversion sequencing (Figure 3). BYTE pin enables full 16-bit parallel output or byte-swapped 8-bit transfers on dedicated pins, while BUSY provides precise latching timing synchronized to conversion completion.

Key Specifications

Pinout & Package

AD976AAR is housed in a 28-lead Small Outline Integrated Circuit (SOIC) package, designated RW-28 per Analog Devices' ordering guide. This surface-mount package measures 7.6 mm × 10.2 mm with 1.27 mm pitch, optimized for automated assembly and thermal performance in industrial environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and MAX1190ECM+, the AD976AAR uniquely combines ±10 V input range, internal 2.5 V reference, on-chip clock, and BYTE-configurable parallel interface in a single SOIC package - making it optimal for legacy industrial designs requiring drop-in compatibility with existing 5 V microcontroller buses and wide-range analog sensors.

Availability

AD976AAR is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, medical data acquisition, and power quality analyzers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD976AAR 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 AD976AAR belongs to Analog Devices' precision SAR ADC product line, engineered for high-accuracy, low-power, single-supply data acquisition in industrial, medical, and test instrumentation where ±10 V range, factory calibration, and robust timing control are critical.

FAQ

What is the maximum sampling rate supported by the AD976AAR?

The AD976AAR supports a maximum throughput rate of 200 kSPS, corresponding to a 5 µs complete conversion cycle. This is achieved using the internal clock and confirmed across all grades (A/B/C) under –40°C to +85°C operation with VANA = VDIG = +5 V. The AD976AAR datasheet specifies t7 + t8 = 5 µs as the minimum time between conversions, enabling deterministic real-time sampling in closed-loop control systems.

Does the AD976AAR require an external reference voltage?

No, the AD976AAR does not require an external reference voltage - it includes a factory-trimmed 2.5 V internal reference accessible at the REF pin. An external reference (2.3 V to 2.7 V) may be used to override the internal reference, but doing so forfeits the guaranteed full-scale linearity unless the external source meets tight tolerance and drift specs. The internal reference delivers ±0.5% full-scale error and ±7 ppm/°C drift, sufficient for most industrial applications.

How is the AD976AAR's analog input protected against overvoltage?

The AD976AAR features ±25 V absolute maximum rating on the VIN pin, providing inherent overvoltage protection beyond its ±10 V operating range. This withstands transients from field wiring, relay bounce, or ESD events without external clamping. The specification confirms recovery to full accuracy within 150 ns after a 2× full-scale overvoltage event, ensuring minimal disruption to continuous acquisition sequences in harsh industrial settings.

What package type is used for the AD976AAR, and what are its key mechanical properties?

The AD976AAR uses a 28-lead Small Outline Integrated Circuit (SOIC) package with RW-28 designation - measuring 7.6 mm × 10.2 mm with 1.27 mm lead pitch. It is RoHS-compliant, surface-mount compatible, and rated for –40°C to +85°C operation. Thermal resistance is θJA = 72°C/W, supporting reliable operation at 100 mW dissipation without heatsinking in standard PCB layouts.

Can the AD976AAR interface directly with a 3.3 V microcontroller?

The AD976AAR digital outputs are specified for VOH ≥ +4 V (ISOURCE = 500 µA) and VOL ≤ +0.4 V (ISINK = 1.6 mA) with VDIG = +5 V, making direct connection to 3.3 V logic unsafe without level translation. Its digital inputs accept VIH ≥ +2.0 V, so 3.3 V controllers can drive AD976AAR control lines (R/C, CS, BYTE), but bidirectional data bus interfacing requires a 5 V-tolerant level shifter or buffer to prevent damage and ensure valid logic thresholds.