Datasheet

Data Sheet AD5686/AD5684
Rev. A | Page 23 of 28
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
RESET
select pin. It is necessary to
keep
RESET
low for a minimum of 30 ns 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 8). Any events on
LDAC
or
RESET
during power-on reset are ignored.
RESET SELECT PIN (RSTSEL)
The AD5686/AD5684 contain a power-on reset circuit that
controls the output voltage during power-up. By connecting
the RSTSEL pin low, the output powers up to zero scale. Note
that this is outside the linear region of the DAC. By connecting
the RSTSEL pin high, V
OUT
powers up to midscale. The output
remains powered up at this level until a valid write sequence
is made to the DAC.