ISL6113 Datasheet, PDF (15/24 Pages) Intersil Corporation – Dual Slot PCI-E Hot Plug Controllers

ISL6113, ISL6114
where 500kΩ is (nominal V_FILTER/nominal I_FILTER) and
where t_FILTER is the desired response time with the values for
I_FILTER and V_FILTER being found in the ISL6113, ISL6114’s
“Electrical Specifications Table” on page 6. See Table 3 for
nominal t_FILTER times for given C_FILTER cap values.
For the ISL6113, there is a minimum t_FILTER consideration
since the ISL6113 has its CR feature invoked as it turns-on the
FETs into the load. There is a maximum bulk capacitance
specified for each power level supported that needs to be
charged at the CR limit. This in-rush current time must be
considered when programming the t_FILTER.
TABLE 3.
NOMINAL t_FILTER DURATION
C_FILTER CAPACITANCE (µF)
TIME (ms)
Open
0.01
0.01
5
0.022
11
0.047
24
0.1
50
NOTE: Nom. CR_DUR = C_FILTER cap (µF) * 500kΩ.
Holding the CFILTER pin low will increase the CR duration
indefinitely. This feature may be useful in trouble shooting, or
evaluation. If this is invoked be cautious not to violate the
SOA of the pass FETs.
Power-Down Cycle
When signaled off, the GATE pins are discharged/charged with
a 25µA for ISL6113 (5µA for ISL6114) current sink/source to
ramp down the supplies in a controlled fashion. When a slot is
turned off, internal switches are connected to the outputs
12V_OUT and 3V_OUT providing a discharge path for load
capacitance. This ensures that the outputs are pulled to
GND, thereby ensuring 0V on slot connectors during
removal or insertion of add-in cards.
Thermal Shutdown
The internal VAUX switches are protected against damage not
only by current limiting, but by a dual mode over-temperature
protection scheme as well. Each slot controller on the ISL6113,
ISL6114 is thermally isolated from the other. Should an
overcurrent condition raise the junction temperature of one
slots controller and pass switch > T_OVER (nominally +140°C),
all of the outputs for that slot will be shut off and the slots FAULT
output will be asserted. The other slots operating condition will
remain unaffected. However, should the ISL6113, ISL6114’s die
temperature exceed +160°C, all outputs for both slots will be
shut off, whether or not a current limit condition exists.
Special I/O
Power Good Outputs (PWRGD)
The ISL6113, ISL6114 have two open-drain, active-low
PWRGD outputs that must be pulled up to VSTBY. This
output will be asserted when a slot has been enabled and
the 12VMAIN, 3VMAIN and VAUX outputs exceed their
respective V_UVTH levels.
PCI-E Reset Outputs (PERST)
A PCI-Express specific output, the ISL6113, ISL6114 have
two open-drain, active-low PERST outputs that must be
pulled up to VSTBY. Upon enabling, the assertion high of
PERST is delayed a minimum of 100ms (t_PVPERL) from the
power rails achieving minimum specified operating limits for
stability of supplies and REFCLK. Once high the card
functions can safely start-up. PERST is immediately pulled
low when the power supply is disabled.
Force_On Inputs (FORCE_ON)
These inputs are provided to facilitate system diagnostics or
evaluation when using the ISL6113, ISL6114. Asserting a
FORCE_ON input will turn on all three of the slots outputs,
while over riding all three supplies overcurrent, the MAIN
supplies UV protections, on-chip thermal protection for the
VAUX supplies and disable the PWRGD and FAULT outputs.
Asserting the FORCE_ON inputs will not disable the
V_UVLO(STBY). If not used, each pin should be connected to
VSTBY.
General Purpose I/O (GPI, GPO)
Two pairs of pins on the ISL6113, ISL6114 are available for
buffered driving. Both of these are compliant to 3.3V. If
unused, connect each GPI pin to GND. The GPI pins are
5ms debounced for filtering and the GPO are open drain
capable of 90mA pull down current for attention getting
devices in accordance with the PCI-Express specifications.
Latch/Retry Operation Toggle (L/R)
This input pin is tied to GND for a ~1.5s retry period after
fault. If left open or tied high to VSTBY, the ISL6113, ISL6114
will latch off upon a fault.
Board Present Input (PRSNT)
The PRSNT input is used to detect the presence of an add-in
card in the slot. In systems where Manual Retention Latch
(MRL) is not implemented, this input detects when an add-in
card is properly inserted into the slot via the last make,
staggered length PRSNT connection on the add-in card
connector. This input must be pulled to ground through the add-
in card ensuring all connections have been made between the
connector and the card in order to enable 3.3VAUX turn-on.
This pin function can be defaulted by tying to GND. PRSNT not
being pulled low overrides and disables all FORCE_ON, ON
and AUXEN commands and for ~5ms after being pulled low. In
systems where MRL is implemented this input is connected to
the MRL sensor. The MRL Sensor allows monitoring of the
position of the MRL and therefore allows detection of
unexpected openings of the MRL. These inputs are internally
pulled up to the VSTBY rail. All I/O are valid at VSTBY <1V.
15
FN6457.0
September 25, 2007