Analog Devices Inc. AD7771BCPZ

Overview

AD7771BCPZ from Analog Devices is an 8-channel, 24-bit simultaneous sampling Σ-Δ ADC with per-channel PGA (gains 1/2/4/8), internal 2.5 V reference, and dual operating modes (high resolution: 107 dB SNR at 32 kSPS; low power: 5.25 mW/channel). It supports true differential or single-ended inputs and is used in precision power quality monitoring and EEG systems.

For engineers reviewing the AD7771BCPZ datasheet, AD7771BCPZ pinout, AD7771BCPZ application, or AD7771BCPZ equivalent, key selection considerations include simultaneous 24-bit sampling across eight channels, sinc3/sinc5 filter latency trade-offs, SRC programmability for coherent line-frequency sampling, and integrated SAR ADC for diagnostics without sacrificing main channel availability.

Technical Context

The AD7771BCPZ integrates eight independent Σ-Δ modulators with configurable sinc3 or sinc5 digital filters, enabling low-latency, high-accuracy conversion per channel. Each channel features a capacitive PGA with 1/2/4/8 gain settings and ±4 nA differential input bias current, supporting direct sensor interfacing without external amplification.

It implements two distinct digital interfaces: a dedicated data output interface (DOUTx) for streaming Σ-Δ results and a separate SPI port for register configuration, SAR ADC control, and diagnostic access. The sample rate converter (SRC) provides fine-grained ODR tuning down to 15.2 µSPS resolution, critical for maintaining coherence with 0.01 Hz line frequency variations.

Key Specifications

Pinout & Package

The AD7771BCPZ is housed in a 64-lead LFCSP (9 mm × 9 mm, 0.8 mm pitch) package with exposed thermal pad. Pin functions are defined per the Analog Devices AD7771 Rev. C datasheet, Section "Pin Configuration and Function Descriptions" (page 14).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7779BCPZ, the AD7771BCPZ adds integrated diagnostics and programmable SRC for line-coherent sampling; compared with LTC2378-24IUK#PBF, it provides true 8-channel simultaneity and sensor-ready input architecture - making AD7771BCPZ uniquely suited for power, medical, and industrial systems requiring phase-aligned, self-validating measurements.

Availability

AD7771BCPZ is available at Aetrix Electronics and suitable for power quality monitoring, electroencephalography (EEG), and industrial process control applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7771BCPZ 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.

The AD7771BCPZ belongs to Analog Devices' precision Σ-Δ ADC product line, designed specifically for high-accuracy, multi-channel data acquisition in power, medical, and industrial instrumentation where simultaneous sampling, low input bias, and integrated diagnostics are essential.

FAQ

What is the maximum simultaneous sampling rate supported by the AD7771BCPZ?

The AD7771BCPZ supports up to 128 kSPS per channel in high resolution mode using the sinc5 filter. This rate is maintained across all eight channels simultaneously, with inter-channel skew under 1 ns. At lower ODRs (e.g., 32 kSPS), the device achieves 107 dB SNR and ±8 ppm INL - specifications confirmed in the Rev. C datasheet Table 1 under "Σ-Δ ADC Speed and Performance."

Does the AD7771BCPZ include an internal voltage reference, and what is its accuracy?

Yes, the AD7771BCPZ integrates a 2.5 V internal reference with initial accuracy of ±2.5 mV (±0.1%) at 25°C and a typical temperature coefficient of ±10 ppm/°C over −40°C to +105°C. This reference drives all eight ADC channels and is buffered internally - eliminating need for external reference components in most applications, as specified in the "REFERENCE" section of the Rev. C datasheet (page 5).

How does the AD7771BCPZ handle synchronization across multiple devices?

The AD7771BCPZ uses dedicated SYNC_IN, SYNC_OUT, and START pins to coordinate sampling across multiple units. A master device's SYNC_OUT can drive SYNC_IN of slaves, while START initiates synchronized conversion start across all devices. Timing parameters (t28, t29, t30) are specified in Table 4 of the Rev. C datasheet, ensuring sub-microsecond inter-device alignment for coherent multi-board systems.

What is the purpose of the integrated SAR ADC in the AD7771BCPZ?

The integrated 12-bit SAR ADC in the AD7771BCPZ serves as an independent diagnostic engine. It validates Σ-Δ channel performance without interrupting primary measurements, supports functional safety standards (e.g., IEC 61508), and monitors internal nodes via built-in multiplexing. Its 256 kSPS throughput and ±1.5 LSB INL are detailed in the "SAR ADC" subsection of the Rev. C datasheet (page 7).

Can the AD7771BCPZ operate with single-ended analog inputs?

Yes, the AD7771BCPZ supports both true differential and single-ended input configurations per channel. In single-ended mode, each AINx+ input accepts 0 V to VREF/PGAGAIN, with ±8 nA typical input current in high resolution mode. Input common-mode range spans AVSSx + 0.10 V to AVDD1x − 0.10 V, as verified in Table 1 "ANALOG INPUTS" of the Rev. C datasheet (page 5).