Sigma-Delta A/D Converter Provides Single Configurable & Reusable Data Acquisition Footprint for AC & DC Performance

Analog Devices Inc. (ADI) introduced the AD7768-1, a low power, high performance, 24-bit single channel sigma-delta (ΣΔ) A/D for precision conversion of both AC and DC signals. AD7768-1 enables power efficient instrumentation solutions for condition monitoring in predictive maintenance (vibration and power quality), audio test, acoustic, structural health and modular automated electrical test equipment. Healthcare applications such as clinical EEG/EMG/ECG are also enabled.

The AD7768-1 provides a single configurable and reusable data acquisition footprint, establishing a new industry standard in combined AC and DC performance. This enables instrumentation and industrial system designers in reuse of core acquisition chain which can service multiple measurement variants, both in channel to channel isolated and non-isolated applications. A single converter serving the various equipment platforms, performance points and measurement ranges reduces the number of reference designs, reducing costs and time to market.

The AD7768-1 includes a power scalable ΣΔ modulator and digital filter to enable synchronized, high-fidelity measurement of AC and DC signals in instrumentation. The high throughput and 110.8 kHz input bandwidth of the AD7768-1 deliver test cost and time reduction, improving the quality and integrity of test measurements.

The AD7768-1 offers extensive digital filtering capabilities, which can be selected to meet a wide range of system requirements catering to high accuracy frequency domain measurements and low latency DC input measurement. The ADC also provides an integrated pre-charge buffer on each analog input, greatly simplifying the design of external driver circuitry. A full buffer input on the reference delivers a high impedance input for any external reference.

The 24-bit AD7768-1 delivers the industry’s best integral nonlinearity (INL) and lowest distortion performance across the widest available bandwidth. It also achieves 20x better offset drift, 40x reduction in gain error and 3x improvement in gain drift over alternative products. Choosing the correct ADC driver is important in obtaining the maximum performance from the AD7768-1.