Voltage Compensation
Signal interface translates a physical measurement into a voltage that varies in direct proportion to the supply voltage of the sensor. The ratiometric analog output governs the transfer function of sensors connected to analog-to-digital converters that share the same supply. It stops applying if the supply voltage falls below the regulation limits of the internal circuitry.
Reference Dependency
Supply fluctuations do not introduce errors in ratiometric architectures. Because the ratiometric analog output shifts in tandem with the supply voltage of the analog-to-digital converter, the digital representation of the signal remains constant. This behavior eliminates the need for expensive, high-precision voltage references in the system.
Signal Conditioning
Calibration parameters must be calculated relative to the supply voltage. For a ratiometric analog output, the zero-point offset and span are defined as percentages of the supply voltage rather than absolute millivolt values. This approach simplifies the calibration process across a wide range of operating conditions.
Error Budget
Noise on the power supply line can still affect performance. If the supply voltage contains high-frequency ripple that exceeds the bandwidth of the ratiometric analog output tracking loop, it can introduce measurement noise. Designers must implement proper filtering and decoupling on the supply lines.
