Datasheet

DAC1220
www.ti.com ...................................................................................................................................... SBAS082G –FEBRUARY 1998–REVISED SEPTEMBER 2009
Table 13. Command Register Bits (continued)
BIT(S) NAME VALUE DESCRIPTION
2 MSB Selects the order in which bits are shifted in and out of the DAC1220, except
when writing to the command register. The command register is always written
to MSB first. Reads from the command register are according to this bit.
0 Data is shifted MSB first (default).
1 Data is shifted LSB first.
1-0 MD Operating mode.
00b Normal mode (default).
01b Self calibration mode. (No other bits should be changed in the Command
Register when setting this mode.)
10b Sleep mode.
11b Reserved.
Data Input Register (DIR)
The Data Input Register determines the output After reset, the OCR contains zero. See the
voltage in Normal mode. Calibration section for further details about the OCR.
In Sleep mode, writing to this register has no effect
Full-Scale Calibration Register (FCR)
on the output, but the value is stored. The value in
the DIR becomes effective immediately upon entering The Full-Scale Calibration Register stores the gain
Normal mode. calibration constant. The content of the DIR is
adjusted multiplicatively by this value before
After reset, the DIR contains zero.
conversion by the DAC.
See the section, Setting the Output Voltage for further
In Sleep mode, writing to this register has no effect
details about the Data Input Register.
on the output, but the value is stored. The value in
the FCR becomes effective immediately upon
Offset Calibration Register (OCR)
entering Normal mode.
The Offset Calibration Register contains a 24-bit
After reset, the FCR contains 800000h.
two's complement value. This value is added to the
value in the DIR before conversion by the DAC. See the Calibration section for further details about
the FCR.
In Sleep mode, writing to this register has no effect
on the output, but the value is stored. The value in
the OCR becomes effective immediately upon
entering Normal mode.
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