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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 new file mode 100644 index 000000000000..b168aa44b233 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 @@ -0,0 +1,53 @@ +What: /sys/bus/iio/devices/iio:deviceX/boost_current_gain +KernelVersion: 6.4 +Contact: linux-iio@vger.kernel.org +Description: + This attribute is used to set the gain of the biasing current + circuit of the Delta-Sigma modulator. The different BOOST + settings are applied to the entire modulator circuit, including + the voltage reference buffers. + +What: /sys/bus/iio/devices/iio:deviceX/boost_current_gain_available +KernelVersion: 6.4 +Contact: linux-iio@vger.kernel.org +Description: + Reading returns a list with the possible gain values for + the current biasing circuit of the Delta-Sigma modulator. + +What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_mux_enable +KernelVersion: 6.4 +Contact: linux-iio@vger.kernel.org +Description: + This attribute is used to enable the analog input multiplexer + auto-zeroing algorithm (the input multiplexer and the ADC + include an offset cancellation algorithm that cancels the offset + contribution of the ADC). When the offset cancellation algorithm + is enabled, ADC takes two conversions, one with the differential + input as VIN+/VIN-, one with VIN+/VIN- inverted. In this case the + conversion time is multiplied by two compared to the default + case where the algorithm is disabled. This technique allows the + cancellation of the ADC offset error and the achievement of + ultra-low offset without any digital calibration. The resulting + offset is the residue of the difference between the two + conversions, which is on the order of magnitude of the noise + floor. This offset is effectively canceled at every conversion, + so the residual offset error temperature drift is extremely low. + Write '1' to enable it, write '0' to disable it. + +What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_ref_enable +KernelVersion: 6.4 +Contact: linux-iio@vger.kernel.org +Description: + This attribute is used to enable the chopping algorithm for the + internal voltage reference buffer. This setting has no effect + when external voltage reference is selected. + Internal voltage reference buffer injects a certain quantity of + 1/f noise into the system that can be modulated with the + incoming input signals and can limit the SNR performance at + higher Oversampling Ratio values (over 256). To overcome this + limitation, the buffer includes an auto-zeroing algorithm that + greatly reduces (cancels out) the 1/f noise and cancels the + offset value of the reference buffer. As a result, the SNR of + the system is not affected by this 1/f noise component of the + reference buffer, even at maximum oversampling ratio values. + Write '1' to enable it, write '0' to disable it. |