Datasheet

AD5623R/AD5643R/AD5663R Data Sheet
Rev. E | Page 24 of 32
INTERNAL REFERENCE SETUP
The on-chip reference is off at power-up by default. This
reference can be turned on or off by setting a software
programmable bit, DB0, in the control register. Table 16 shows
how the state of the bit corresponds to the mode of operation.
Command 111 is reserved for setting up the internal reference
(see Table 8). See Table 16 for the contents of the input shift
register during the internal reference setup command.
Table 16. Reference Setup Register
Internal Reference
Setup Register (DB0)
Action
0 Reference off (default)
1 Reference on
Table 17. 32-Bit Input Shift Register Contents for Reference Setup Function
MSB LSB
DB23 to DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 to DB1 DB0
x 1 1 1 x x x x 1/0
Don’t care
Command bits (C2 to C0)
Address bits (A2 to A0)
Don’t care
Reference
setup register