Datasheet

MAX5823/MAX5824/MAX5825
Ultra-Small, Octal Channel, 8-/10-/12-Bit Buffered
Output DACs with Internal Reference and I
2
C Interface
30Maxim Integrated
DEFAULT Command
The DEFAULT command (B[23:20] = 0110) selects the
default value for selected DACs. DACs which are not
selected do not update their default settings in response
to the command. These default values are used for all
future watchdog, clear, and gate operations. The new
default setting is determined by bits DF[2:0] (B[7:5])
while the affected DAC(s) are selected using B[15:8].
This command is inaccessible when a watchdog timeout
has occurred and the watchdog timer is configured with
a safety level of high or max. Note the selected default
values do not apply to resets initiated by SW_RESET
commands or supply cycling, both of which return all
DACs to the values determined by the M/Z input and
reset this register to M/Z mode.
Available default values (DF[2:0]):
M/Z (000): DAC channel defaults to value as selected by
the M/Z input (default).
ZERO (001): DAC channel defaults to zero scale.
MID (010): DAC channel defaults to midscale.
FULL (011): DAC channel defaults to full scale.
RETURN (100): DAC channel defaults to the value pro-
grammed by the RETURN command.
No Effect (101, 110, 111): DAC channel default behavior
is unchanged.
Table 11. DEFAULT Command Format
B23 B22 B21 B20 B19 B18 B17 B16 B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
0 1 1 0 0 0 0 0 7 6 5 4 3 2 1 0 DF2 DF1 DF0 X X X X X
DEFAULT Command Reserved Multiple DAC Selection
Default Values:
000: M/Z
001: ZERO
010: MID
011: FULL
100: RETURN
101+: No Effect
Don’t Care
Default Value → 1 1 1 1 1 1 1 1 0 0 0 X X X X X
Command Byte Data High Byte Data Low Byte