The DADS7779 is an 8-channel synchronous sampling ADC. It integrates eight complete Σ-Δ ADCs on-chip. The functional block diagram is shown in Figure 1. This product offers ultra-low input current, allowing direct connection to sensors. Each input channel has a programmable gain amplifier with gains of 1, 2, 4, and 8, which maps low-amplitude sensor outputs to the full-scale ADC input range, maximizing the dynamic range of the signal chain. The reference voltage range is 1V to 3.6V. The analog inputs accept unipolar (0V to VREF) or true bipolar (±VREF/2) analog input signals, with an analog supply voltage selectable at 3.3V or ±1.65V. 

The analog inputs can be configured to accept true differential or single-ended signals to match different sensor output configurations. The ADC data output interface is dedicated to sending ADC conversion results to the processor.

The SPI interface is used to read and write the ADC configuration register. The SPI interface can also be configured to output the conversion data from the A/D converter. The product also includes a 12-bit SAR ADC. This ADC can be used for product diagnostics, eliminating the need to dedicate a separate Σ-Δ ADC channel for system measurement functions. Through a multiplexer, the SAR ADC can be used to verify the measurement results of the Σ-Δ ADC in applications requiring functional safety. 

The product offers two operating modes: high-resolution mode and low-power mode. High-resolution mode provides higher dynamic range, while low-power mode reduces power consumption at a lower dynamic range specification. The product is compatible with and can replace the Analog Devices AD7779.

• 8-channel, 24-bit synchronous sampling analog-to-digital converter.
• Unipolar (3.3V) or bipolar ( ±1.65V) power supply options available.
• Each channel has a programmable gain amplifier (PGA, with gains of 1, 2, 4, and 8).
• The maximum output data rate per channel can reach 16KSPS.
• Supports single-ended or true differential input.
• The built-in auxiliary SAR ADC can be used for system and chip diagnostics.

• Breaker.
• General Data Acquisition.
• Medical Electronics.
• Industrial Control Systems.
• Instrument measurement.