The LLSDADC100dB is a low power variant of our high-resolution sigma-delta analog-to-digital converter family. It achieves a dynamic range of more than 100 dB, at a power consumption of only 1.6 mW.

The latency of the ADC is only one clock cycle (40 ns at 25 MHz), which makes the converter ideally suited for application in control loops. The low latency is enabled by feeding the bitstream output back to the input via a DAC with build-in filtering. This creates a “tracking ADC behavior”, where the output accurately tracks the input signal inside the signal bandwidth. Next to enabling low latency, the filtering DAC also makes the system robust towards jitter and other error sources typically associated with 1-bit converters.

The LLSDADC100dB can convert both single-ended and differential signals with high accuracy. Next to this it can convert signals with amplitudes and biasing levels well outside its own supply level, by using external resistors acting as level shifters.

More information is available in the datasheet. The functional block diagram is shown below.