Analog Devices Inc. AD7676ASTZ

Overview

AD7676ASTZ from Analog Devices is a 16-bit, 500 kSPS, fully differential successive-approximation register (SAR) ADC with ±2.5 V input range, 1 LSB INL max, and no missing codes. It operates from a single 5 V supply, delivers 94 dB SNR at 45 kHz, and supports parallel (8-/16-bit) or SPI/QSPI/MICROWIRE-compatible serial interface - used in high-precision medical CT scanners and spectrum analyzers.

For engineers reviewing the AD7676ASTZ datasheet, AD7676ASTZ pinout, AD7676ASTZ application, or AD7676ASTZ equivalent, this page provides verified technical context, real-world interface timing constraints, confirmed package mapping to 48-lead LQFP, validated differential input behavior, and two field-tested alternative parts with documented functional trade-offs.

Technical Context

The AD7676ASTZ implements a charge redistribution SAR architecture with internal conversion clock and hardware-calibrated error correction circuitry. Its differential input stage achieves 79 dB CMRR at 10 kHz and supports true bipolar operation without pipeline delay.

It features dual interface modes: 16-bit parallel bus with BYTESWAP/OB/2C configuration control, and 2-wire serial mode with programmable internal SCLK division (via DIVSCLK[1:0]), active-low SYNC framing, and configurable SDOUT edge alignment via INVSCLK and INVSYNC pins.

Key Specifications

Pinout & Package

AD7676ASTZ is packaged in a 48-lead LQFP (ST-48), with exposed pad for thermal performance. Pin 1 identifier located at top-left corner; pins arranged in quad configuration with analog, digital, and I/O power domains isolated per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7675ASTZ, AD7676ASTZ delivers tighter INL for metrology-critical paths; versus AD7682BCPZ, it offers higher throughput, dual interface support, and 5 V operation - making AD7676ASTZ optimal for high-fidelity, multi-interface industrial and medical systems.

Availability

AD7676ASTZ is available at Aetrix Electronics and suitable for CT scanners, spectrum analyzers, portable medical instruments, and industrial process controllers requiring stable component supply across extended product lifecycles.

Supply support for AD7676ASTZ 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, headquartered in Norwood, MA.

The AD7676ASTZ belongs to Analog Devices' PulSAR® family of precision SAR ADCs, engineered for applications demanding high resolution, low noise, and zero-latency conversion in medical imaging and test equipment.

FAQ

What is the absolute maximum input voltage for AD7676ASTZ analog inputs?

The AD7676ASTZ analog inputs (IN+, IN–, REF, REFGND) tolerate voltages from AGND – 0.3 V to AVDD + 0.3 V. Exceeding this range risks permanent damage due to ESD diode conduction. For ±2.5 V operation, AVDD must be ≥4.75 V, and input signals must stay within –0.1 V to +3.0 V relative to AGND. Always observe these limits in AD7676ASTZ designs.

Does AD7676ASTZ require an external reference, and what are the key requirements?

Yes, AD7676ASTZ requires an external precision reference applied to REF and REFGND pins. The reference voltage must be between 2.3 V and (AVDD – 1.85 V), typically 2.5 V. It must source up to 170 µA at 500 kSPS and exhibit low noise (<10 µV p-p) and drift (<3 ppm/°C) - ADR421 or REF192 are validated choices for AD7676ASTZ systems.

How does the SER/PAR pin affect AD7676ASTZ interface behavior?

When SER/PAR is LOW, AD7676ASTZ enables its 16-bit parallel interface (D[15:0], RD, CS); when HIGH, it configures D[8:11] and D[13:16] as serial port signals (SDOUT, SCLK, SYNC, RDERROR). This pin determines physical bus allocation and must be set before initialization. Incorrect SER/PAR state prevents communication - a critical setup step for every AD7676ASTZ implementation.

Can AD7676ASTZ operate with a 3 V digital interface while using a 5 V analog supply?

Yes. AD7676ASTZ supports mixed-voltage operation: AVDD and DVDD at 5 V for analog/digital core, while OVDD can be set to 2.7–5.25 V - enabling direct connection to 3 V logic (e.g., FPGA I/O banks). Digital input thresholds scale with OVDD, and outputs swing from 0 V to OVDD. This dual-supply flexibility is confirmed in AD7676ASTZ timing specs and recommended for 3 V host interfaces.

What is the significance of the BYTESWAP and OB/2C pins on AD7676ASTZ?

BYTESWAP controls byte ordering on the parallel bus: LOW outputs LSB on D[7:0], MSB on D[15:8]; HIGH swaps them. OB/2C selects output coding: HIGH = straight binary (0x0000 to 0xFFFF), LOW = twos complement (0x8000 to 0x7FFF). These pins allow AD7676ASTZ to match host processor endianness and arithmetic conventions without software bit manipulation - reducing firmware overhead in real-time AD7676ASTZ systems.