Supply Allocation Exposure across Dual Sourced Low Tier Commercial Sensor Topologies
Dual sourcing low tier commercial sensors demands matching ASIC DSP group delays and thermal offset drift profiles to prevent host control loop instability.
Ratiometric PSRR
Rejection Measurement
Supply rejection metrics for analog sensors define the ability of a circuit to ignore fluctuations in the excitation voltage. The ratiometric psrr describes this rejection when the output signal is also a fraction of the supply voltage. This parameter is critical for sensors that use the same source for both power and reference.
It ensures that the measurement remains accurate even if the battery voltage drops.
Voltage Reference
Most analog to digital converters compare an input signal to a known reference. In a ratiometric system, any change in the supply affects both the sensor output and the converter reference proportionally. These changes cancel each other out in the digital domain.
This technique eliminates the need for expensive high precision voltage regulators.
Error Cancellation
The effectiveness of this rejection is measured in decibels. A high value indicates that very little of the supply noise reaches the final data. Drift in the supply voltage would otherwise appear as a false change in the physical measurement.
Performance is verified by injecting a small alternating current signal onto the power line.
Operating Range
Sensors must maintain this ratiometric behavior across their entire specified voltage window. Performance degrades if the internal circuitry saturates.