Analog Devices Inc. AD7671ASTZ

Overview

AD7671ASTZ from Analog Devices is a 16-bit, 1 MSPS charge redistribution SAR analog-to-digital converter operating from a single 5 V supply. It delivers ±2.5 LSB max INL, 90 dB SNR at 250 kHz, and supports bipolar (±10 V, ±5 V, ±2.5 V) and unipolar (0–10 V, 0–5 V, 0–2.5 V) input ranges. It is used in high-accuracy data acquisition systems requiring no pipeline delay and dual serial/parallel interface flexibility.

For engineers reviewing the AD7671ASTZ datasheet, AD7671ASTZ pinout, AD7671ASTZ application, or AD7671ASTZ equivalent, this page provides verified technical context, mode-specific timing behavior, real-world interface configuration options (SPI/QSPI/MICROWIRE/DSP-compatible), and validated alternatives for precision ADC selection in instrumentation and spectrum analysis.

Technical Context

The AD7671ASTZ implements a factory-calibrated charge redistribution DAC architecture with internal error correction, enabling guaranteed no missing codes and ≤2.5 LSB INL across –40°C to +85°C. Its three hardware-selectable modes-Warp (1 MSPS, 1 ms max inter-conversion interval), Normal (800 kSPS, no timing constraint), and Impulse (666 kSPS, power scaled with throughput)-are controlled via dedicated WARP/IMPULSE pins.

It integrates a resistor-based analog input scaler supporting six configurable voltage ranges, an on-chip track-and-hold with 2 ns aperture delay and 5 ps rms jitter, and dual interface paths: 16-bit parallel (8/16-bit byte-swappable) and 2-wire serial compatible with 3 V or 5 V logic levels.

Key Specifications

Pinout & Package

AD7671ASTZ is available in a 48-lead LQFP (ST-48) package with exposed paddle connected to AGND. Pin functions are validated per Analog Devices' official AD7671 datasheet Rev. C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7671ASTZ, AD7665ASTZ offers lower cost and proven field reliability but sacrifices 75% throughput and 4 dB SNR; AD7679ACPZ trades speed for two extra bits of resolution and requires package migration - making AD7671ASTZ optimal for balanced speed/accuracy/power in space-constrained industrial DAQ.

Availability

AD7671ASTZ is available at Aetrix Electronics and suitable for high-speed data acquisition, spectrum analysis, and medical instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for AD7671ASTZ 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 Norwood, MA.

The AD7671ASTZ belongs to the PulSAR® family of precision SAR ADCs designed for applications demanding high speed, high resolution, and low power in single-supply, space-constrained systems - especially where pipeline latency is unacceptable.

FAQ

What are the supported analog input voltage ranges for the AD7671ASTZ?

The AD7671ASTZ supports bipolar ranges of ±10 V, ±5 V, and ±2.5 V, and unipolar ranges of 0 V to 10 V, 0 V to 5 V, and 0 V to 2.5 V. These are selected by configuring the four analog input terminals (INA, INB, INC, IND) per Table I in the datasheet. The internal resistor scaler ensures full 16-bit performance across all ranges without external gain stages. Each range maintains the same ±2.5 LSB INL and 90 dB S/(N+D) specification when operated within rated conditions.

Does the AD7671ASTZ require an external reference voltage?

Yes, the AD7671ASTZ requires an external reference voltage applied to the REF pin, with a valid range of 2.3 V to 2.5 V. The REFGND pin must be tied directly to AGND to minimize noise coupling. Reference current draw is 200 µA at 1 MSPS throughput. Using a low-noise, high-stability reference such as the ADR435 is recommended to preserve the ADC's 2.5 LSB INL and 90 dB SNR performance. The AD7671ASTZ does not include an internal reference.

How does the Warp Mode timing constraint affect system design with the AD7671ASTZ?

In Warp Mode, the AD7671ASTZ achieves 1 MSPS throughput but requires consecutive conversions to occur within ≤1 ms to guarantee full specified accuracy. If the inter-conversion interval exceeds 1 ms (e.g., after power-up or idle periods), the first conversion result must be discarded. This mandates either continuous sampling or firmware handling to discard the initial sample. The AD7671ASTZ BUSY signal and CNVST timing (t2 = 1 ms max) must be synchronized accordingly - unlike Normal Mode, which imposes no minimum rate.

Can the AD7671ASTZ interface directly with a 3 V microcontroller?

Yes, the AD7671ASTZ supports direct 3 V logic interfacing via its OVDD supply pin, which accepts 2.7 V to 5.25 V. When OVDD = 3 V, all digital outputs (D[15:0], BUSY, SYNC, SDOUT) are 3 V compliant, and digital inputs (CS, RD, SER/PAR, etc.) accept 3 V logic levels. No level shifters are needed. The parallel interface operates in 8-bit or 16-bit mode with BYTESWAP control, and the serial interface remains SPI/QSPI/MICROWIRE-compatible regardless of OVDD voltage.

Is the AD7671ASTZ pin-to-pin compatible with other PulSAR ADCs?

The AD7671ASTZ is explicitly documented as pin-to-pin compatible with the AD7665ASTZ and AD7664ASTZ in the 48-lead LQFP package. This allows direct upgrade paths with no PCB changes. However, it is not pin-compatible with higher-resolution variants like AD7679ACPZ (LFCSP-only) or AD7676 (different pinout). Functional compatibility extends to shared control signals (CNVST, BUSY, CS, RD), but mode selection (WARP/IMPULSE) and serial interface pins (DIVSCLK, INVSYNC, etc.) differ in implementation and timing.