AAT4290/4291
I/O Expander Load Switches with Serial Control
10 4290.2005.01.1.0
Output Sequencing
If output sequencing is not necessary, then all of the
outputs will be switched on simultaneously on the
first rising edge of the EN/SET pin. However, if out-
put sequencing is desired, then a series of pulses
on the EN/SET pin will accomplish this. Each time
a new group of pulses is asserted on EN/SET, the
AAT4290/1 internal control is reset. For example, to
sequence the outputs in order from OUT5 to OUT1,
five clocks bursts are input on the EN/SET pin.
From Table 1, the first burst of 16 clocks turns on
OUT5. A following burst of 8 clocks (as the counter
resets) will add OUT4, followed by 4 clocks to add
OUT3, 2 clocks to add OUT2, and 1 clock to add
OUT1. Likewise, the outputs can be turned off in
any order by adding more clock bursts.
Timing Diagram
