Analog Devices Inc. AD7768-4BSTZ-RL

Overview

AD7768-4BSTZ-RL from Analog Devices is a 4-channel, 24-bit simultaneous-sampling sigma-delta ADC with power-scaling architecture, delivering 108 dB dynamic range, ±2 ppm INL, and −120 dB THD at 110.8 kHz input bandwidth. It supports three selectable power modes (fast/median/low) and per-channel digital filtering for high-precision data acquisition in vibration monitoring and medical EEG systems.

For engineers reviewing the AD7768-4BSTZ-RL datasheet, AD7768-4BSTZ-RL pinout, AD7768-4BSTZ-RL application, or AD7768-4BSTZ-RL equivalent, key selection criteria include simultaneous sampling integrity, wideband filter pass-band ripple (±0.005 dB to 102.4 kHz), sinc5 low-latency path (3/ODR group delay), and 64-lead LQFP package compatibility with industrial temperature range (−40°C to +105°C).

Technical Context

The AD7768-4BSTZ-RL implements a per-channel Σ-Δ modulator with independent digital filters-wideband linear-phase (±0.005 dB ripple, 105 dB stop-band attenuation) and low-latency sinc5 (3/ODR group delay). It supports decimation rates from ×32 to ×1024, enabling noise-performance optimization across 13.8–110.8 kHz input bandwidths.

Each channel integrates analog input precharge buffers (−20 µA max input current) and reference precharge buffers to reduce loading on external references and driver stages. Power scaling is implemented via three hardware-selectable modes: fast (256 kSPS, 51.5 mW/channel), median (128 kSPS, 27.5 mW/channel), and low power (32 kSPS, 9.375 mW/channel).

Key Specifications

Pinout & Package

AD7768-4BSTZ-RL is housed in a 64-lead LQFP (10 mm × 10 mm, 0.5 mm pitch) with no exposed pad, rated for −40°C to +105°C operation. Pin functions are defined per Analog Devices' Rev. D datasheet (pp. 24–27).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7768BSTZ-RL, the AD7768-4BSTZ-RL reduces channel count and associated power (51.5 → 20.3 mW in fast mode) without sacrificing per-channel performance; versus ADS131M04IPBSR, it delivers 9.8 kHz more bandwidth, 7 dB higher dynamic range, and dedicated precharge circuitry for demanding sensor interfaces.

Availability

AD7768-4BSTZ-RL is available at Aetrix Electronics and suitable for vibration monitoring, 3-phase power quality analysis, high-precision medical EEG/EMG, audio test equipment, and sonar systems requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for AD7768-4BSTZ-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, founded in 1965 and headquartered in Wilmington, MA.

The AD7768/AD7768-4 product line was designed for high-accuracy, multi-channel data acquisition in industrial, energy, and medical instrumentation-emphasizing simultaneous sampling integrity, configurable power-noise-bandwidth trade-offs, and robust digital interface reliability.

FAQ

What is the maximum input bandwidth supported by the AD7768-4BSTZ-RL?

The AD7768-4BSTZ-RL supports a maximum input bandwidth of 110.8 kHz (−3 dB point) in fast mode with the wideband digital filter enabled. This bandwidth is maintained across all four channels simultaneously and is validated with a 32.768 MHz master clock and decimation rate ×32. The device achieves ±0.005 dB pass-band ripple from dc to 102.4 kHz at 256 kSPS output data rate, making it suitable for high-fidelity spectral analysis applications.

Does the AD7768-4BSTZ-RL support daisy-chaining with other ADCs?

Yes, the AD7768-4BSTZ-RL supports hardware daisy-chaining via its DOUTx and DIN pins, allowing up to eight devices to share a single SPI bus and MCLK/DRDY signals. Each device outputs its channel data sequentially on the shared DOUT line, with frame synchronization ensured by the DRDY pulse. This eliminates the need for additional chip select lines and simplifies firmware handling in multi-ADC systems such as modular data loggers or multi-sensor condition monitoring units.

What power supply configurations are required for the AD7768-4BSTZ-RL?

The AD7768-4BSTZ-RL requires three independent supplies: AVDD1 = 4.5–5.5 V (typ. 5.0 V) for the modulator core, AVDD2 = 2.25–5.0 V for analog front-end biasing, and IOVDD = 1.8 V or 2.5–3.3 V for digital I/O. All supplies must be well-decoupled per the datasheet layout guidelines. The device draws 20.3 mA AVDD1 current in fast mode with analog precharge buffers enabled, resulting in 51.5 mW per channel at 5 V-scalable down to 9.375 mW per channel in low-power mode.

How does the sinc5 filter differ from the wideband filter in the AD7768-4BSTZ-RL?

The sinc5 filter in the AD7768-4BSTZ-RL provides ultra-low latency (group delay = 3/ODR) and is optimized for real-time control loops or transient capture, with −3 dB bandwidth = 0.204 × ODR. In contrast, the wideband filter offers ±0.005 dB pass-band ripple to 102.4 kHz at 256 kSPS and 105 dB stop-band attenuation, ideal for FFT-based spectral analysis. Both filters are independently configurable per channel, enabling hybrid acquisition strategies within a single device.

Is the AD7768-4BSTZ-RL pin-compatible with the AD7768BSTZ-RL?

No, the AD7768-4BSTZ-RL is not pin-compatible with the AD7768BSTZ-RL despite sharing the same 64-lead LQFP package. While both use identical power, ground, clock, and control pins, the AD7768BSTZ-RL exposes eight DOUT lines and eight analog input pairs, whereas the AD7768-4BSTZ-RL uses only four of each-leaving the remaining pins as NC or functionally repurposed. PCB layout must be specific to the selected variant.