AIStorm’s AIS339 Chameleon is an AFE designed to solve the noise and connectivity issues of real-world sensor interface applications at the lowest power and in the smallest footprint possible.
The AIS339 Chameleon is an AFE designed to enable signal capture in difficult real world environments. Baseline capture, common mode accelerated recapture, noise rejection, nuisance signal nulling, multi-order analog filtering, and an up to 6th order almost all pass (Bessel) with mHz bandpass low end corner are example capabilities. To accomplish this the AIS339 includes: i) five input channels and a single reference channel; ii) a programmable gain amplifier (PGA); iii) differential voltage input or transconductor current mode input; iv) a high common mode rejection driver; v) a fast programmable local loop to allow fast capture and recapture of the common mode; vi) a sample and hold circuit allowing fast recovery from events which move the baseline; viii) an up to 6th order ]high order programmable filter response; ix) a buffered differential voltage input between the negative terminals of the instrumentation amplifier to null nuisance signals; x) analog or ADC outputs; xi) an optional two terminal common mode driver; xii) amplifier offset and shift registers. Between the amplifier and the ADC the AIS339 compares to sigma delta solutions with an ENOB of 18 bits but requires substantially less current. The AIS339 is capable of nyquist rate sampling between multiple different sensors. Sample & Hold and fast drift recovery circuitry is provided to remember each sensor’s common mode and return to it when a channel is selected. Also included is a precision on chip analog reference and charge pump to maximize the input common mode range. The AIS339 will operate with a supply voltage as low as 2.7V up to 3.6V and is available in a 5×5 48-pin TQFN package.
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