Analog Devices Inc. AD7764BRUZ

Overview

AD7764BRUZ from Analog Devices is a 24-bit, sigma-delta analog-to-digital converter (ADC) optimized for high-speed, high-precision data acquisition. It delivers 109 dB dynamic range at 312.5 kSPS, features on-chip differential amplifier and reference buffer, supports pin-selectable decimation rates (64×/128×/256×), and operates with ±3.2768 V differential input range using a 4.096 V external reference - ideal for vibration analysis and instrumentation front ends.

For engineers reviewing the AD7764BRUZ datasheet, AD7764BRUZ pinout, AD7764BRUZ application, or AD7764BRUZ equivalent, key selection considerations include its 28-lead TSSOP package, dual-supply operation (2.5 V/5 V), full-band FIR filter with −120 dB stop-band attenuation, overrange alert pin, and daisy-chain capability for synchronized multi-channel systems.

Technical Context

The AD7764BRUZ employs a fourth-order sigma-delta modulator sampling at up to 40 MSPS, followed by a programmable finite impulse response (FIR) digital filter with pass-band ripple ≤0.1 dB and −3 dB bandwidth = ODR × 0.4096 kHz. Its on-chip differential amplifier provides 125 kHz 0.1 dB flatness and common-mode output of 2.048 V, enabling direct interface to transducer outputs without external level-shifting circuitry.

Internal clocking architecture derives ICLK = MCLK/2, supporting master clock frequencies from 500 kHz to 40 MHz. Synchronization via SYNC pin enables deterministic phase alignment across multiple AD7764BRUZ devices, while FSI/SCO/FSO signals implement a flexible SPI-compatible serial interface with 32-bit frame structure for register access and data readout.

Key Specifications

Pinout & Package

AD7764BRUZ is housed in a 4.4 mm × 9.7 mm, 28-lead TSSOP package with exposed pad for thermal enhancement. Pin assignments are fully defined per Analog Devices Rev. D datasheet Figure 5 and Table 5.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-resolution sigma-delta ADC applications.

Compared with AD7764BRUZ, AD7763BRUZ trades serial simplicity for higher throughput and parallel flexibility, while AD7765BRUZ sacrifices speed to achieve superior noise floor - making AD7764BRUZ the optimal balance of speed, resolution, integration, and ease of use in mid-range industrial DAQ systems.

Availability

AD7764BRUZ is available at Aetrix Electronics and suitable for vibration analysis systems, portable data loggers, high-accuracy instrumentation, and multi-channel condition monitoring requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7764BRUZ 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD776x family was designed specifically for high-fidelity, high-speed data acquisition in demanding industrial environments - integrating signal conditioning, filtering, and serial interface to reduce system complexity and improve measurement integrity.

FAQ

What is the maximum sample rate achievable with the AD7764BRUZ?

The AD7764BRUZ achieves a maximum fully filtered output word rate of 312.5 kSPS when configured with 64× decimation and a 40 MHz master clock. This corresponds to a −3 dB bandwidth of approximately 127 kHz (ODR × 0.4096). The device maintains this rate in both normal and low power modes, with dynamic range degrading from 109 dB to 106 dB in low power mode at this speed.

Does the AD7764BRUZ require an external reference voltage?

Yes, the AD7764BRUZ requires an external 4.096 V reference applied to the VREF+ pin. This reference sets the full-scale differential input range to ±3.2768 V. The device includes an on-chip reference buffer (powered by AVDD4) to drive the reference node, reducing sensitivity to source impedance and improving PSRR - but the reference itself must be supplied externally with <±1 µA leakage tolerance.

How does the on-chip differential amplifier in the AD7764BRUZ simplify sensor interfacing?

The AD7764BRUZ on-chip differential amplifier accepts high-impedance sensor signals at VINA+/VINA−, provides 125 kHz 0.1 dB flatness, and outputs a level-shifted differential signal at VOUTA+/VOUTA− with precise 2.048 V common-mode voltage. This eliminates external op-amps and bias networks needed to match the modulator's input common-mode requirement, reducing component count, board space, and potential drift sources in precision measurement systems.

Can multiple AD7764BRUZ devices be synchronized for coherent sampling?

Yes, the AD7764BRUZ includes a dedicated SYNC pin that accepts a falling-edge trigger to reset internal digital filters simultaneously across multiple devices. When combined with identical MCLK sources and matching decimation settings, this enables sub-sample coherent sampling across channels - essential for phase-sensitive applications like multi-axis vibration analysis or beamforming. Daisy-chaining further simplifies control bus routing.

What power supply configurations are required for the AD7764BRUZ?

The AD7764BRUZ requires five independent supplies: AVDD1 (2.5 V for modulator), DVDD (2.5 V for digital core), AVDD2/AVDD3/AVDD4 (5 V or 3.3 V for analog blocks and reference buffer), and AGND/DGND separation. Each supply must be decoupled locally with 100 nF capacitors. AVDD3 and AVDD4 must be ≥3.15 V to support the 4.096 V reference; violating these rail specifications causes gain error and reduced dynamic range in the AD7764BRUZ.