AAT4290 Datasheet, PDF (10/12 Pages) Advanced Analogic Technologies – I/O Expander Load Switches with Serial Control

AAT4290/4291
I/O Expander Load Switches with Serial Control
Timing Diagram
OUTn
EN/SET
T_HI T_LO
T_LAT
T_D(ON) T_R
T_O
T_D(OFF)
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.
10
4290.2005.01.1.0