Multi Coil Quadrature Demodulation Signal Chains for Proximity Measurement
Multi coil quadrature demodulation isolates amplitude and phase in inductive proximity chains, resolving sub-micron targets while rejecting thermal noise.
SAR Converter
Quantization Architecture
Precision analog-to-digital converters are evaluated against absolute reference voltages to quantify integral nonlinearity and offset error across their full input voltage range. A SAR converter uses a successive approximation register coupled with a capacitive digital-to-analog converter to determine digital output codes through binary search comparison steps. Zero latency response renders this architecture optimal for multiplexed data acquisition systems.
Converter resolution scales with the number of internal comparison steps executed per conversion cycle.
Capacitive DAC
Internal switch capacitor arrays redistribute charge during successive comparison bit decisions. In a SAR converter, mismatch in binary-weighted capacitor ratios introduces integral nonlinearity errors. Factory laser trimming or digital calibration routines correct capacitor mismatch to maintain monotonicity across all code transitions.
Comparison Speed
Internal comparator settling time limits the maximum sampling throughput attainable without error. Clock jitter during comparison bit trials degrades SAR converter signal-to-noise ratio performance. High-speed comparator designs balance propagation delay against power consumption in battery-powered instrumentation.
Sample Timing
Sample-and-hold front ends capture fast transient input signals before binary search conversion begins. Input driver bandwidth must allow charge transfer into the internal sampling capacitor within the acquisition window. Proper driver amplifier selection prevents gain errors caused by incomplete settling.