Sigma-Delta A/D converter for power efficient instrumentation solutions

Analog Devices has introduced the AD7768-1, a low power, high-performance, 24-bit single channel sigma-delta A/D for precision conversion AC and DC signals. The device allows power efficient instrumentation solutions for condition monitoring in predictive maintenance (vibration and power quality), acoustic, audio test, structural health and modular automated electrical test equipment. Healthcare applications such as clinical EEG/EMG/ECG are also enabled. The device offers a single configurable and reusable data acquisition footprint, setting a new industry standard in combined AC and DC performance. This allows instrumentation and industrial system designers in the reuse of core acquisition chain that can service many measurement variants, both in channel to channel isolated and non-isolated applications. A single converter attending the various equipment platforms, performance points and measurement ranges lessen the number of reference designs, decreasing costs and time to market. The device includes a power scalable sigma-delta A/D modulator and digital filter to allow synchronised, high-fidelity measurement of AC and DC signals in instrumentation. The high throughput and 110.8kHz input bandwidth of the device provide test cost and time reduction, increasing the quality and integrity of test measurements. The device provides comprehensive digital filtering capabilities, that can be chosen to meet a broad range of system needs catering to high accuracy frequency domain measurements and low latency DC input measurement. The ADC also offers an integrated pre-charge buffer on each analog input, hugely simplifying the design of external driver circuitry. A full buffer input on the reference provides a high impedance input for any external reference.