Datasheet

23Maxim Integrated
18-Bit, Single-Channel, Ultra-Low-Power, Delta-
Sigma ADCs with Programmable Gain and GPIO
MAX11209/MAX11211
SCOC: Self-Calibration Offset Register
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. A write to the self-calibration offset register is allowed. The written value remains valid until it is either rewritten
or until an on-demand self-calibration operation is performed, which overwrites the user-supplied value.
The self-calibration offset value is subtracted from each conversion result provided the NOSCO bit in the CTRL3 reg-
ister 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. The self-calibration offset value is also applied prior to the
2x scale factor associated with unipolar mode.
Table 18. SGC Register (Read/Write)
Table 19. SCOC Register (Read/Write)
SGC: System Gain Calibration Register
The system gain calibration 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 system gain calibration value. The format is always in two’s complement binary
format. A write to the system-calibration register is allowed. The written value remains valid until it is either rewritten or
until an on-demand system-calibration operation is performed, which overwrites the user-supplied value.
The system gain calibration value is used to scale the offset corrected conversion result, provided the NOSYSG bit
in the CTRL3 register is set to 0. The system gain calibration value scales the offset-corrected result by up to 2x or
corrects a gain error of approximately -50%. The amount of positive gain error that can be corrected is determined by
modulator overload characteristics, which can be as much as +25%. The gain is corrected to within 2 LSB.
BIT B23 B22 B21 B20 B19 B18 B17 B16
DEFAULT
0 0 0 0 0 0 0 0
BIT B15 B14 B13 B12 B11 B10 B9 B8
DEFAULT
0 0 0 0 0 0 0 0
BIT B7 B6 B5 B4 B3 B2 B1 B0
DEFAULT
0 0 0 0 0 0 0 0
BIT B23 B22 B21 B20 B19 B18 B17 B16
DEFAULT
0 0 0 0 0 0 0 0
BIT B15 B14 B13 B12 B11 B10 B9 B8
DEFAULT
0 0 0 0 0 0 0 0
BIT B7 B6 B5 B4 B3 B2 B1 B0
DEFAULT
0 0 0 0 0 0 0 0