Analog Devices Inc. AD7765BRUZ-REEL7

Overview

AD7765BRUZ-REEL7 from Analog Devices is a 24-bit sigma-delta analog-to-digital converter (ADC) with on-chip differential amplifier, reference buffer, and full-band FIR filter. It delivers 112 dB dynamic range at 156 kSPS, supports pin-selectable 128×/256× oversampling, operates from 2.5 V and 5 V supplies, and targets high-fidelity data acquisition in vibration analysis and instrumentation systems.

For engineers reviewing the AD7765BRUZ-REEL7 datasheet, AD7765BRUZ-REEL7 pinout, AD7765BRUZ-REEL7 application, or AD7765BRUZ-REEL7 equivalent, key selection considerations include its 156 kSPS fully filtered output rate, ±3.2768 V differential input range with 4.096 V reference, overrange alert pin, daisy-chain capability, and synchronization support for multi-device timing alignment.

Technical Context

The AD7765BRUZ-REEL7 integrates a 40 MSPS analog modulator followed by three cascaded FIR filters enabling decimation rates of 128× or 256×. Its digital filtering achieves −120 dB stop-band attenuation at Nyquist frequency and maintains 0.1 dB pass-band ripple up to ODR × 0.4016 kHz.

It features dual power modes: normal mode draws 371 mW at 40 MHz MCLK and 128× decimation, while low-power mode reduces consumption to 215 mW without sacrificing input bandwidth or output data rate. The on-chip differential amplifier provides 125 kHz 0.1 dB flatness and common-mode output at 2.048 V.

Key Specifications

Pinout & Package

The AD7765BRUZ-REEL7 is housed in a 28-lead TSSOP package with exposed pad for thermal management. Pin functions are validated per Analog Devices Rev. D datasheet (pages 9–10).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7764BRUZ and AD7763BRUZ, the AD7765BRUZ-REEL7 uniquely combines 112 dB dynamic range at 156 kSPS, integrated differential amplifier, full-band FIR filter, and hardware overrange detection - making it optimal for precision-acquisition systems requiring minimal external components and robust signal integrity.

Availability

AD7765BRUZ-REEL7 is available at Aetrix Electronics and suitable for vibration analysis, portable instrumentation, and industrial data acquisition requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7765BRUZ-REEL7 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, communications, automotive, and healthcare markets since 1965.

The AD7765BRUZ-REEL7 belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for high-speed, high-dynamic-range data acquisition where dc accuracy and ac performance must coexist without compromise.

FAQ

What is the maximum output data rate of the AD7765BRUZ-REEL7?

The AD7765BRUZ-REEL7 achieves a maximum fully filtered output word rate of 156.25 kSPS when configured with 128× decimation and a 40 MHz master clock. This rate is derived from the formula [(MCLK/2)/decimation rate], and is confirmed in the Rev. D datasheet Table 2 under "Decimate 128×" conditions. At this rate, the AD7765BRUZ-REEL7 maintains 112 dB dynamic range and −120 dB stop-band attenuation.

Does the AD7765BRUZ-REEL7 require an external reference voltage?

Yes, the AD7765BRUZ-REEL7 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 and establishes the 2.048 V common-mode bias point for the on-chip differential amplifier. The device includes an on-chip reference buffer (powered by AVDD4) to drive this reference, but the reference source itself must be supplied externally.

How does the DEC_RATE pin configure the AD7765BRUZ-REEL7?

The DEC_RATE pin on the AD7765BRUZ-REEL7 selects between two oversampling ratios: grounding the pin configures 256× decimation (78.125 kSPS output), while applying 2.5 V configures 128× decimation (156.25 kSPS output). This hardware-based selection bypasses register writes and ensures deterministic filter configuration at power-up, as documented in the Pin Function Descriptions section (page 9) of the Rev. D datasheet.

Can multiple AD7765BRUZ-REEL7 devices be synchronized?

Yes, the AD7765BRUZ-REEL7 supports hardware synchronization via its dedicated SYNC pin. A falling edge on this pin resets the internal digital filter state across all connected devices, enabling phase-aligned sampling in multi-channel systems. This feature is explicitly described in the "Synchronization" section (page 22) and validated in timing diagrams Figure 2–4 of the Rev. D datasheet.

What is the purpose of the OVERRANGE pin on the AD7765BRUZ-REEL7?

The OVERRANGE pin on the AD7765BRUZ-REEL7 is an open-drain output that asserts logic high when the analog input signal approaches the modulator's input limit - indicating imminent saturation. This hardware alert enables real-time gain adjustment or system-level alarms without software polling, and is functionally distinct from status register flags. Its behavior is defined in Table 5 (Pin No. 9) and used in applications like transient impact detection in condition monitoring.