Analog Devices Inc. AD977AARSZ

Overview

AD977AARSZ from Analog Devices is a 16-bit, 200 kSPS successive-approximation analog-to-digital converter (ADC) operating from a single 5 V supply. It features an on-chip 2.5 V reference, high-speed serial interface, and supports ±10 V, ±5 V, ±3.3 V bipolar and 0 V–10 V/0 V–5 V/0 V–4 V unipolar input ranges - deployed in precision industrial data acquisition and process control systems.

For engineers reviewing the AD977AARSZ datasheet, AD977AARSZ pinout, AD977AARSZ application, or AD977AARSZ equivalent, key selection criteria include throughput rate (200 kSPS), internal/external reference flexibility, power-down mode (50 µW), serial data format (binary two's complement or straight binary), and SOIC-20 package compatibility with legacy AD977 designs.

Technical Context

The AD977AARSZ implements a factory-calibrated switched-capacitor SAR architecture with integrated clock generation and dual-mode serial interface (internal or external DATACLK). Its conversion control relies on R/C and CS signals, supporting both continuous and discontinuous clocking with SYNC frame synchronization for multi-device daisy-chaining via TAG.

It delivers full-scale accuracy across ±10 V bipolar and 0 V–10 V unipolar ranges, with DC specifications including ±3 LSB integral linearity error (A grade), ±0.5% full-scale error, and 1 µs transient response. AC performance includes 83 dB SNR, 83 dB S/(N+D), and 90 dB SFDR at 20 kHz input - validated under –40°C to +85°C operation.

Key Specifications

Pinout & Package

AD977AARSZ is housed in a 20-lead Skinny SOIC (SOIC-20) package with standard 0.3-inch body width and 0.050-inch lead pitch. Thermal resistance θ_JA = 75°C/W enables operation up to +85°C ambient without forced airflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7606BSTZ and ADS8860IDRCT, the AD977AARSZ uniquely combines single-supply 5 V operation, factory-calibrated bipolar input ranges, internal reference, and TAG-enabled daisy-chaining - making it the only option among the three that supports low-complexity, multi-node, ±10 V precision acquisition without external reference or level-shifting circuitry.

Availability

AD977AARSZ is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, medical instrumentation, and energy metering requiring stable component supply and long-term obsolescence management.

Supply support for AD977AARSZ 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, serving industrial, communications, automotive, and healthcare markets since 1965.

The AD977AARSZ belongs to Analog Devices' precision SAR ADC product line, engineered for high-resolution data acquisition in environments demanding low power, excellent DC accuracy, and flexible interface options - especially where space, cost, and design simplicity constrain multi-channel alternatives.

FAQ

What is the maximum sampling rate supported by the AD977AARSZ?

The AD977AARSZ supports a maximum throughput rate of 200 kSPS, corresponding to a complete conversion cycle time of 5 µs. This specification applies across all grade versions (A/B/C) and is guaranteed over the full –40°C to +85°C operating temperature range with 5 V supplies. The AD977AARSZ achieves this rate using its internal clock or synchronized external DATACLK, with timing validated per Table 4 of the Rev. E datasheet.

Does the AD977AARSZ include an internal voltage reference?

Yes, the AD977AARSZ integrates a factory-trimmed 2.5 V ±2% internal reference accessible at the REF pin. It can be used directly or overridden by an external 2.3 V–2.7 V reference. A 2.2 µF tantalum capacitor must be connected between REF and AGND2, and another between CAP and AGND2, to ensure stability and accuracy. This eliminates the need for external reference ICs in many precision applications.

How does the TAG pin function in the AD977AARSZ?

The TAG pin on the AD977AARSZ enables daisy-chain configuration of multiple devices on a shared DATA line. When EXT/INT = HIGH and an external DATACLK is used, the logic level present on TAG at conversion start is output on DATA after 16 or 17 DATACLK cycles - allowing time-multiplexed readout of conversion results from up to four AD977AARSZ units without additional select lines or buffers.

What package type is used for the AD977AARSZ?

The AD977AARSZ is supplied in a 20-lead Skinny SOIC (SOIC-20) package with 0.3-inch body width and 0.050-inch lead pitch. This package is RoHS-compliant, surface-mountable, and thermally rated for θ_JA = 75°C/W. Pinout and mechanical dimensions are fully documented in Figures 3 and 32 of the Rev. E datasheet.

Can the AD977AARSZ operate with bipolar input signals?

Yes, the AD977AARSZ supports true bipolar input ranges of ±10 V, ±5 V, and ±3.3 V, as well as unipolar ranges of 0 V–10 V, 0 V–5 V, and 0 V–4 V. Bipolar operation requires proper external resistor network configuration per Table 8 and Figure 14–16 in the datasheet, with zero-error calibrated to ±10 mV (A grade) and drift of ±2 ppm/°C.