ISL6123_07 Datasheet, PDF (18/21 Pages) Intersil Corporation – Power Sequencing Controllers

ISL6123, ISL6124, ISL6125, ISL6126, ISL6127, ISL6128, ISL6130
ENABLE
POWER
SUPPLY
OE
LOW = RESET
SYSRST#
ISL6124
#N
G
UVLO
A
T
ENABLE# ^E
RESET#
TO LOGIC
INPUT
ENABLE#
SYSRST#
ISL6125 _L
# N+1 _O
G
RESET#
I
UVLO
C
RESET#
RESET#
FIGURE 19. MULTIPLE ISL612X SERIAL CONFIGURATION
Voltage Tracking
In some applications the various voltages may have to track
each other as they ramp up and down, whereas others may
just need sequencing. In these cases tracking can be
accomplished and has been demonstrated over a wide
range of load current (1A to 10A) and load capacitance
(10µF to 3300µF) with the ISL612X family. Figure 20 and
Figure 21 illustrate output voltage ramping tracking
performance, note that differences are less than 0.5V. With
the relevant GATE pins tied together in a star pattern, so that
the resistance between any two GATE pins is equivalent (1k
to 10k) results in a sharing of the GATE ramping voltage and
with the same or similar enough FETs this behavior is
observed.
It is suggested that this circuit implementation be prototyped
and evaluated for the particular expected loads prior to
committing to manufacturing build.
FIGURE 20. OUTPUT VOLTAGE ON LOW TO HIGH TRACKING
FIGURE 21. OUTPUT VOLTAGE HIGH TO LOW TRACKING
18
FN9005.8
February 5, 2007