1 What: /sys/bus/iio/devices/iio:deviceX/boost_current_gain
3 Contact: linux-iio@vger.kernel.org
5 This attribute is used to set the gain of the biasing current
6 circuit of the Delta-Sigma modulator. The different BOOST
7 settings are applied to the entire modulator circuit, including
8 the voltage reference buffers.
10 What: /sys/bus/iio/devices/iio:deviceX/boost_current_gain_available
12 Contact: linux-iio@vger.kernel.org
14 Reading returns a list with the possible gain values for
15 the current biasing circuit of the Delta-Sigma modulator.
17 What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_mux_enable
19 Contact: linux-iio@vger.kernel.org
21 This attribute is used to enable the analog input multiplexer
22 auto-zeroing algorithm (the input multiplexer and the ADC
23 include an offset cancellation algorithm that cancels the offset
24 contribution of the ADC). When the offset cancellation algorithm
25 is enabled, ADC takes two conversions, one with the differential
26 input as VIN+/VIN-, one with VIN+/VIN- inverted. In this case the
27 conversion time is multiplied by two compared to the default
28 case where the algorithm is disabled. This technique allows the
29 cancellation of the ADC offset error and the achievement of
30 ultra-low offset without any digital calibration. The resulting
31 offset is the residue of the difference between the two
32 conversions, which is on the order of magnitude of the noise
33 floor. This offset is effectively canceled at every conversion,
34 so the residual offset error temperature drift is extremely low.
35 Write '1' to enable it, write '0' to disable it.
37 What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_ref_enable
39 Contact: linux-iio@vger.kernel.org
41 This attribute is used to enable the chopping algorithm for the
42 internal voltage reference buffer. This setting has no effect
43 when external voltage reference is selected.
44 Internal voltage reference buffer injects a certain quantity of
45 1/f noise into the system that can be modulated with the
46 incoming input signals and can limit the SNR performance at
47 higher Oversampling Ratio values (over 256). To overcome this
48 limitation, the buffer includes an auto-zeroing algorithm that
49 greatly reduces (cancels out) the 1/f noise and cancels the
50 offset value of the reference buffer. As a result, the SNR of
51 the system is not affected by this 1/f noise component of the
52 reference buffer, even at maximum oversampling ratio values.
53 Write '1' to enable it, write '0' to disable it.