Datasheet

AD5689/AD5687 Data Sheet
Rev. 0 | Page 22 of 24
HARDWARE RESET (
RESET
)
RESET
is an active low reset that allows the outputs to be cleared
to either zero scale or midscale. The clear code value is user
selectable via the power-on reset select pin (RSTSEL).
RESET
must be kept low for a minimum amount of time to complete
the operation (see
Figure 2). When the
RESET
signal is returned
high, the output remains at the cleared value until a new value is
programmed. The outputs cannot be updated with a new value
while the
RESET
pin is low. There is also a software executable
reset function that resets the DAC to the power-on reset code.
Command 0110 is designated for this software reset function
(see
Table 9). Any events on
LDAC
or
RESET
during a power-
on reset are ignored.
RESET SELECT PIN (RSTSEL)
The AD5689/AD5687 contain a power-on reset circuit that
controls the output voltage during power-up. When the RSTSEL
pin is connected low (to GND), the output powers up to zero scale.
Note that this is outside the linear region of the DAC. When the
RSTSEL pin is connected high (to V
LOGIC
), V
OUT
X powers up to
midscale. The output remains powered up at this level until a
valid write sequence is sent to the DAC.