AD5066
POWER-ON RESET
The AD5066 contains a power-on reset circuit that controls
the output voltage during power-up. By connecting the POR
pin low, the AD5066 output powers up to 0 V; by connecting
the POR pin high, the AD5066 output powers up to midscale.
The output remains powered up at this level until a valid write
sequence is made to the DAC. This is useful in applications
where it is important to know the state of the output of the DAC
while it is in the process of powering up. There is also a software
executable reset function that resets the DAC to the power-on
reset code. Command 0111 is reserved for this reset function
(see Table 7). Any events on LDAC or CLR during power-on
reset are ignored.
Table 10. 32-Bit Input Shift Register Contents for Power-Up/Power-Down Function
MSB
DB31 to
DB23 to
DB28 DB27 DB26 DB25 DB24 DB20
DB10 to
DB4 to
DB19 DB9 DB8 DB7
X
0
1
0
0
X
X
PD1 PD0 X
Don’t
cares
Command bits (C2 to C0)
Address bits
(A3 to A0)—
don’t cares
Don’t
cares
Power-down Don’t
mode
cares
LSB
DB3 DB2 DB1 DB0
DAC D DAC C DAC B DAC A
Power-down/power-up channel
selection—set bit to 1 to select
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