Analog Devices Inc. AD7761BSTZ-RL

Overview

AD7761BSTZ-RL from Analog Devices is an 8-channel, simultaneous-sampling sigma-delta ADC optimized for high-precision ac/dc data acquisition. It delivers 97.7 dB dynamic range, ±1 LSB INL, and 110.8 kHz input bandwidth in fast mode, with programmable power scaling across three operating modes - enabling synchronized measurement of vibration, power quality, and biomedical signals in industrial and medical instrumentation.

For engineers reviewing the AD7761BSTZ-RL datasheet, AD7761BSTZ-RL pinout, AD7761BSTZ-RL application, or AD7761BSTZ-RL equivalent, key selection criteria include simultaneous 16-bit sampling across eight channels, selectable sinc5 or wideband digital filtering, CRC-protected serial interface, and support for 1.8 V/2.5 V/3.3 V IOVDD with dual analog supply rails (5 V AVDD1, 2.25–5 V AVDD2).

Technical Context

The AD7761BSTZ-RL integrates eight independent Σ-Δ modulators and per-channel digital filter engines, supporting true simultaneous sampling with no inter-channel skew. Its architecture enables real-time trade-offs among input bandwidth (13.8–110.8 kHz), output data rate (32–256 kSPS), and power (9.375–51.5 mW per channel), all configurable via SPI or pin control.

Dual digital filter paths - low-latency sinc5 (3/ODR group delay) and linear-phase wideband filter (±0.005 dB ripple to 102.4 kHz at 256 kSPS) - are selectable per channel. Embedded precharge buffers reduce analog input current to −20 µA and minimize reference loading, while CRC error checking ensures integrity on the 8-bit parallel DOUTx interface.

Key Specifications

Pinout & Package

AD7761BSTZ-RL is housed in a 64-lead LQFP package (10 mm × 10 mm body, 12 mm × 12 mm PCB footprint) with no exposed pad. Pin functions are defined per the functional block diagram and Pin Configuration section of the Rev. A datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision, multi-channel sigma-delta ADC applications.

Compared with AD7761BSTZ-RL, AD7762BSTZ offers higher resolution but sacrifices programmable bandwidth and power scaling, while ADS131M08IPBSR reduces BOM count with integrated features but compromises on analog input drive robustness and inter-channel timing fidelity.

Availability

AD7761BSTZ-RL is available at Aetrix Electronics and suitable for data acquisition systems, industrial control loops, and high-precision medical instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7761BSTZ-RL 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 AD7761BSTZ-RL belongs to Analog Devices' precision sigma-delta ADC product line, engineered for demanding simultaneous-sampling applications in power quality, structural health monitoring, and clinical biosensing where timing integrity, noise performance, and configurability are critical.

FAQ

What is the maximum output data rate per channel for AD7761BSTZ-RL?

The AD7761BSTZ-RL supports a maximum output data rate of 256 kSPS per channel in fast mode, achieved with a 32.768 MHz master clock and decimation rate of ×32. This ODR corresponds to a 110.8 kHz input bandwidth and consumes 51.5 mW per channel. Lower ODRs (128 kSPS, 32 kSPS) are available in median and low-power modes to optimize noise or power for specific application requirements.

Does AD7761BSTZ-RL support simultaneous sampling across all eight channels?

Yes, AD7761BSTZ-RL implements true simultaneous sampling using eight independent Σ-Δ modulators - one per channel - with no shared sampling clock tree. This architecture ensures zero inter-channel skew and preserves phase relationships between channels, which is essential for accurate 3-phase power analysis, multi-axis vibration monitoring, and coherent audio test setups.

What digital filter options does AD7761BSTZ-RL provide, and how do they differ in use cases?

AD7761BSTZ-RL offers two per-channel digital filter paths: the sinc5 filter (3/ODR group delay, ideal for low-latency control loops) and the wideband filter (±0.005 dB passband ripple to 102.4 kHz at 256 kSPS, optimal for frequency-domain analysis). The wideband filter provides 105 dB stopband attenuation, while sinc5 enables faster step response - allowing mixed-mode acquisition in a single device.

Can AD7761BSTZ-RL operate with a 1.8 V IOVDD supply?

Yes, AD7761BSTZ-RL fully supports 1.8 V IOVDD operation, as confirmed in the Rev. A datasheet Section "1.8 V IOVDD Timing Specifications." Logic levels, timing margins, and output drive strength are characterized for this voltage, enabling compatibility with modern low-voltage FPGAs and microcontrollers while maintaining full functionality including SPI control and parallel DOUTx interface.

What is the role of the analog input precharge buffers in AD7761BSTZ-RL?

The analog input precharge buffers in AD7761BSTZ-RL reduce differential input current to −20 µA and minimize dependence on input common-mode voltage. This feature lowers loading on high-impedance sensors (e.g., piezoelectric accelerometers or isolated amplifiers), prevents rail-dependent nonlinearity, and improves THD performance - especially critical in battery-powered or high-channel-count DAQ systems where external buffering is impractical.