MAX11253 Datasheet, PDF (48/51 Pages) Maxim Integrated Products – Longer Battery Life for Portable Applications

MAX11253
16-Bit, 6-Channel, 64ksps, 6.2nV/√Hz PGA,
Delta-Sigma ADC with SPI Interface
SCOC: Self-Calibration Offset Calibration Register (Read/Write)
Default = 0x00_0000
BIT NAME
B23
B22
B21
….
B3
B2
B1
B0
DEFAULT
0
0
0
….
0
0
0
0
The self-calibration offset register is a 24-bit read/write register. The data written/read to/from this register is clocked in/out MSB
first. This register holds the self-calibration offset value. The format is always in two’s complement binary format. An internal self-
calibration does not overwrite the SCOC register.
The readback value of this register depends on CTRL3:CALREGSEL. A ‘1’ reads back the user programmed value. A ‘0’ reads back
the results of an internal register as described in CTRL3:CALREGSEL. The internal register can only be read during conversion.
The self-calibration offset value is subtracted from each conversion result—provided the NOSCO bit in the CTRL3 register is set to
‘0’. The self-calibration offset value is subtracted from the conversion result before the self-calibration gain correction and before the
system offset and gain correction. It is also applied prior to the 2x scale factor associated with unipolar mode. When a self-calibration
is in progress, this register is not writable by the user.
SCGC: Self-Calibration Gain Calibration Register (Read/Write)
Default = 0xBF_851B
BIT NAME
B23
B22
B21
….
B3
B2
B1
B0
DEFAULT
1
0
1
….
1
0
1
1
The self-calibration gain register is a 24-bit read/write register. The data written/read to/from this register is clocked in/out MSB first.
This register holds the self-calibration gain value. The format is unsigned 24-bit binary. An internal self- calibration does not overwrite
the SCGC register.
The readback value of this register depends on CTRL3:CALREGSEL. A ‘1’ reads back the user programmed value. A ‘0’ reads back
the results of an internal register as described in CTRL3:CALREGSEL. The internal register can only be read during conversion.
The self-calibration gain calibration value is used to scale the self-calibration offset corrected conversion result before the system offset
and gain calibration values have been applied – provided the NOSCG bit in the CTRL3 register is set to ‘0’. The self-calibration gain
calibration value scales the self-calibration offset corrected conversion result by up to 2x or can correct a gain error of approximately
–50%. The gain will be corrected to within 2 LSB. When a self- calibration is in progress, this register is not writable by the user.
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