JAJSRI9A October 2023 – March 2024 LM51772
ADVANCE INFORMATION
The cable drop compensation feature helps to keep the output voltage at the nominal value over a wide range of load current without the need for additional remote sensing. The voltage drop compensation measures the current and feeding back the current information to the internal voltage control loop of the converter
If enabled, the gm stage of the current monitor sensor (ISNSP/N ) sends a proportional current to the CDC pin. The voltage across the CDC pin is applied as a offset to the nominal output voltage. It is recommended to select the resistor value on the CDC-pin not to exceed 1V. The Equation below:
The CDC function can operate for the internal or external feedback divider with the same behavior.
To achieve a accurate operation for the desired range cable drop compensation the gain of the CDC offset can be programmed by the CDC_GAIN register bits.
The CDC function operates equally with the external Feedback divider. It's recommended to use a 100kΩ feedback divider top resistance.
The figure below shows the control curve of the CDC feature.