AD7768BSTZ-RL

Overview

The AD7768BSTZ-RL is an 8-channel, 24-bit simultaneous sampling sigma-delta analog-to-digital converter (ADC) from Analog Devices. It features a maximum output data rate of 256 kSPS per channel and supports input bandwidths up to 110.8 kHz. The device provides 108 dB dynamic range with ±2 ppm integral nonlinearity (INL), ±50 µV offset error, and ±30 ppm gain error. It operates on AVDD1 = 5.0 V, AVDD2 = 2.25 V to 5.0 V, and IOVDD = 2.5 V to 3.3 V or 1.8 V. Packaged in a 64-lead LQFP, it functions within a temperature range of -40°C to +105°C.

Feature Summary

• Simultaneous sampling across all channels for synchronized data acquisition.
• Configurable power modes allowing trade-offs between speed, noise, and power dissipation.
• Embedded analog precharge buffers on inputs and references to reduce current glitches.
• Integrated digital filters including wideband linear phase and low latency sinc5 options.

Applications

• Data acquisition systems utilizing USB, PXI, or Ethernet interfaces.
• Instrumentation and industrial control loops requiring high precision.
• Audio test and measurement equipment.
• Vibration and asset condition monitoring applications.
• High precision medical electroencephalogram (EEG) and electrocardiogram (ECG).

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm package type and reel specifications. Ensure compatibility with required supply voltages and interface standards before procurement. Cross-reference the component revision history for any functional updates or pinout changes that may impact integration.

Selection Notes

Select this component when simultaneous multi-channel sampling is required with high dynamic range. Evaluate the available power modes to balance performance against thermal constraints. Confirm that the SPI interface and data format align with the host processor capabilities. Verify that the operating temperature range meets the environmental requirements of the target application.

Part Context

This part belongs to the AD7768 family of high-performance ADCs. It serves as the 8-channel variant within a series that includes single and four-channel versions. The family shares common architectural features such as sigma-delta modulation and programmable digital filtering, providing a scalable solution for various data acquisition needs.

Replacement Considerations

The AD7768-4BSTZ-RL is a verified 4-channel substitute within the same family. It maintains identical electrical characteristics and pinouts for the shared channels but offers reduced channel count. Designers should verify software configuration adjustments required for the different channel count.

FAQ

What are the selectable power modes for the AD7768?

The device offers three modes: Fast mode (256 kSPS, 110.8 kHz BW), Median mode (128 kSPS, 55.4 kHz BW), and Eco mode (32 kSPS, 13.8 kHz BW).

Does the AD7768 support daisy-chaining?

Yes, the device supports daisy-chaining via its serial data interface to connect multiple units.

What is the function of the analog input precharge buffers?

The precharge buffers reduce analog input current and minimize glitches on the reference input terminals during sampling transitions.