A semicustom VLSI chip for real-time adaptive sampling has been designed. The chip executes the fan algorithm at a rate of about 1 μs per sample, an order of magnitude faster than a previous realization using general-purpose signal processing chips. This increased speed allows the use of higher peak sampling rates in acquiring cardiac signals with high-frequency components. In addition, the chip provides improved accuracy and extends the maximum number of consecutive redundant samples to 32K compared to 256 for the prototype.