Analog Devices Inc. AD977ACRSZ

Overview

AD977ACRSZ 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 internal 2.5 V reference, high-speed serial interface, on-chip clock, and supports ±10 V, ±5 V, and 0 V–5 V input ranges - used in precision industrial data acquisition systems requiring low power and factory-calibrated linearity.

For engineers reviewing the AD977ACRSZ datasheet, AD977ACRSZ pinout, AD977ACRSZ application, or AD977ACRSZ equivalent, this page delivers verified specifications, real-world timing behavior, package-specific terminal mapping, and validated alternative options for embedded process control, ATE, and automated test instrumentation design.

Technical Context

The AD977ACRSZ implements a factory-calibrated switched-capacitor SAR architecture with integrated reference buffer and dual-mode serial interface (internal or external DATACLK). Its conversion control relies on R/C and CS signals, supporting both continuous and discontinuous clock read modes with SYNC frame synchronization when EXT/INT = HIGH.

It delivers 83 dB SNR and 90 dB SFDR at 20 kHz input, with 1 µs transient response and 150 ns overvoltage recovery. Full-scale error is ±0.5% (typ ±0.3%) with ±7 ppm/°C drift, and power dissipation is 100 mW max in active mode, dropping to 50 µW in PWRD HIGH state.

Key Specifications

Pinout & Package

AD977ACRSZ is packaged in a 20-lead skinny SOIC (SOIC_N) with 0.3" body width and standard JEDEC MS-013AC footprint. Pin functions are electrically and mechanically validated per Analog Devices Rev. E datasheet Figures 3 and Table 6.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and MAX11902ETX+, the AD977ACRSZ uniquely supports ±10 V bipolar input, internal/external reference selection, and 50 µW power-down - making it optimal for legacy industrial systems requiring wide dynamic range and thermal stability without MCU voltage translation.

Availability

AD977ACRSZ is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, and scientific instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD977ACRSZ 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, founded in 1965 and headquartered in Wilmington, MA.

The AD977 family was designed for high-accuracy, low-power data acquisition in harsh industrial environments - emphasizing factory-calibrated DC performance, robust AC specs, and flexible serial interfacing for embedded controllers.

FAQ

What input voltage ranges does the AD977ACRSZ support?

The AD977ACRSZ supports bipolar input ranges of ±10 V, ±5 V, and ±3.3 V, and unipolar ranges of 0 V–10 V, 0 V–5 V, and 0 V–4 V. Configuration is achieved using external resistor networks per Table 8 in the Rev. E datasheet. The AD977ACRSZ maintains specified INL and DNL across all ranges, with full-scale error drift ≤ ±7 ppm/°C for internal reference use.

Does the AD977ACRSZ require an external reference, or can it operate with its internal reference?

The AD977ACRSZ can operate with its internal 2.5 V reference (2.48 V–2.52 V) or accept an external 2.3 V–2.7 V reference applied to the REF pin. When using the internal reference, a 2.2 µF tantalum capacitor must be connected between CAP and AGND2. The AD977ACRSZ achieves ±0.5% full-scale error with internal reference and ±0.5% with external 2.5 V source, making external reference optional for most precision applications.

How does the AD977ACRSZ handle power-down mode, and what is its recovery time?

When the PWRD pin is driven HIGH, the AD977ACRSZ enters power-down mode, reducing power dissipation to 50 µW and halting conversions while retaining the last conversion result in its internal shift register. Recovery to full accuracy requires 1 ms after PWRD returns LOW, provided a 2.2 µF capacitor is connected to CAP. This behavior is confirmed in Table 1 and Table 2 of the AD977ACRSZ Rev. E datasheet.

What is the maximum DATACLK frequency supported by the AD977ACRSZ in external clock mode?

In external clock mode (EXT/INT = HIGH), the AD977ACRSZ supports a maximum DATACLK period of 66 ns (15.15 MHz), as specified in Table 4 of the Rev. E datasheet. At this rate, the AD977ACRSZ achieves ~195 kSPS effective throughput when reading data after conversion completion - slightly below its rated 200 kSPS due to timing overhead, but fully compliant with timing margins.

Can multiple AD977ACRSZ devices be daisy-chained on a single DATA line?

Yes - the AD977ACRSZ supports daisy-chaining via the TAG input and SYNC output. When EXT/INT = HIGH, the TAG logic level from one device is output on DATA after 16–17 DATACLK periods, allowing multiple AD977ACRSZ units to share a single serial bus. This capability is documented in Figure 11 and the "Use of the TAG Input" section of the Rev. E datasheet, and applies directly to the AD977ACRSZ variant.