Analog Devices Inc. AD977ACRZ

Overview

AD977ACRZ 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, and 0 V–5 V input ranges - deployed in precision industrial data acquisition systems requiring low power and factory-calibrated linearity.

For engineers reviewing the AD977ACRZ datasheet, AD977ACRZ pinout, AD977ACRZ application, or AD977ACRZ equivalent, this page delivers verified specifications, real-world timing behavior, package-specific terminal roles, and validated alternative options for system-level design and BOM continuity planning.

Technical Context

The AD977ACRZ implements a factory-calibrated switched-capacitor SAR architecture with internal clock generation and dual-mode serial data output (internal or external DATACLK). Its conversion control relies on R/C and CS signals, supporting both continuous and discontinuous external clocking with SYNC frame synchronization.

It integrates a 2.5 V internal reference (±2 mV initial accuracy), configurable input ranges via external resistor networks (Table 8), and power-down mode reducing dissipation to 50 µW. Aperture delay is fixed at 40 ns, and transient response to full-scale step is 1 µs - critical for dynamic signal capture in closed-loop control.

Key Specifications

Pinout & Package

AD977ACRZ is supplied in a 20-lead skinny SOIC (SOIC_N) package with 0.3" body width and standard JEDEC MS-013AC footprint. Pin spacing is 0.050", lead finish is matte tin, and thermal resistance θ_JA = 75°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision SAR ADC applications.

Compared with ADS8860IDRCT and MAX11902ETX+, the AD977ACRZ offers unique factory-calibrated bipolar input capability and proven long-term stability in industrial temperature ranges - making it optimal for legacy-replacement and calibration-critical applications where pin compatibility and deterministic linearity outweigh raw speed.

Availability

AD977ACRZ is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, medical instrumentation, and energy metering applications requiring stable component supply, long-lifecycle support, and guaranteed traceability.

Supply support for AD977ACRZ 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, serving industrial, automotive, communications, and healthcare markets.

The AD977A product line delivers precision, low-power SAR ADCs optimized for factory-calibrated, single-supply operation in harsh industrial environments - emphasizing dc accuracy, thermal stability, and robust serial interfacing without external support components.

FAQ

What is the maximum sampling rate supported by the AD977ACRZ?

The AD977ACRZ supports a maximum throughput rate of 200 kSPS, corresponding to a complete conversion cycle time of 5 µs. This is confirmed in Table 2 of the Rev. E datasheet under AD977A–Specifications. The AD977ACRZ achieves this rate using its internal successive-approximation architecture and on-chip clock, with timing parameters t6 (conversion time) and t7 (acquisition time) jointly defining the 5 µs throughput time.

Does the AD977ACRZ require an external reference voltage?

No, the AD977ACRZ does not require an external reference voltage. It integrates a precision 2.5 V internal reference (2.48 V to 2.52 V) with ±2 ppm/°C drift, fully specified in Table 2 and Figure 25. An external reference may be applied via the REF pin only if tighter stability or custom voltage is needed - but the internal reference suffices for most industrial applications requiring ±0.5% full-scale accuracy.

Which package type is used for the AD977ACRZ?

The AD977ACRZ uses a 20-lead skinny SOIC (SOIC_N) package, as explicitly stated in the "Features" section and confirmed in Figure 3 and the Ordering Guide of the Rev. E datasheet. This package has a 0.3-inch body width, JEDEC MS-013AC outline, and is distinct from the 28-lead SSOP variant (AD977ARSZ). Pin count, thermal metrics (θ_JA = 75°C/W), and footprint are all specific to this SOIC configuration.

Can the AD977ACRZ operate with bipolar input ranges like ±10 V?

Yes, the AD977ACRZ natively supports bipolar input ranges including ±10 V, ±5 V, and ±3.3 V, as documented in the General Description, Table 1, and Applications Information sections. Configuration is achieved via external resistor networks connected to R1IN, R2IN, and R3IN pins per Table 8 - no internal register writes or firmware configuration is needed to enable bipolar mode.

How does the power-down mode function in the AD977ACRZ?

In power-down mode, asserted by driving the PWRD pin HIGH, the AD977ACRZ reduces power dissipation to 50 µW while retaining the last conversion result in its internal shift register. Conversions are inhibited, but the stored 16-bit value remains accessible via serial readout. Recovery to full accuracy takes 1 ms after PWRD is deasserted, as specified in Table 1 under "Recovery to Rated Accuracy After Power-Down".