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CS209A
CS209A
Proximity Detector
Description
The CS209A is a bipolar monolithic integrated circuit for use in metal detection/proximity sensing applications. The IC (see block diagram) contains two on-chip current regulators, oscillator and low-level feedback circuitry, peak detection/demodulation circuit, a comparator and two complementary output stages. The oscillator, along with an external LC network, provides controlled oscillations where amplitude is highly dependent on the Q of the LC tank. During low Q conditions, a variable low-level feedback circuit provides drive to maintain oscillation. The peak demodulator senses the negative portion of the oscillator envelop and provides a demodulated waveform as input to the comparator.