Internally, the LDC measures inductance shifts with 16 bits of resolution, while the conversion output word width is only 12 bits. For systems in which the sensor signal variation is less than 25% of the full scale range, the LDC can report conversion results with higher resolution by setting the Output Gain. The Output Gain is applied to all device channels. An output gain can be used to apply a 2-bit, 3-bit, or 4-bit shift to the output code for all channels, providing an effectively higher measurement resolution. When the Gain function is used, additional LSBs of the conversion word are reported, while the corresponding number of MSBs are not reported.
To avoid data corruption issues, use the Output Gain function (Data Offset) to shift the output codes to prevent toggling of the shifted MSBs.
|CHANNEL(1)||REGISTER||FIELD [ BIT(S) ]||VALUES||EFFECTIVE RESOLUTION (BITS)||OUTPUT RANGE|
|All||RESET_DEV, addr 0x1C||OUTPUT_GAIN [ 10:9 ]||00 (default): Gain =1 (0 bits shift)||12||100% full scale|
|01: Gain = 4 (2 bits left shift)||14||25% full scale|
|10: Gain = 8 (3 bits left shift)||15||12.5% full scale|
|11 : Gain = 16 (4 bits left shift)||16||6.25% full scale|
Example: If the conversion result for a channel is 0x07A3, with OUTPUT_GAIN=0x0, the reported output code is 0x07A. If OUTPUT_GAIN is set to 0x3 in the same condition, then the reported output code is 0x7A3. The original 4 MSBs (0x0) are no longer accessible. Figure 51 illustrates the segments of the 16-bit sample that is reported for each possible gain setting.