MIC2592B Datasheet, PDF (6/31 Pages) Micrel Semiconductor – Dual-Slot PCI Express Hot-Plug Controller

MIC2592B
Pin Description (continued)
Pin Number
Pin Name
39
A2
40
A1
41
A0
48
SDA
47
SCL
37
/INT
17
GND
33
46
20
RFILTER[A&B]
7
NC
18
19
30
Micrel
Pin Function
SMBus Address Select Pins: Connect to ground or leave open in order to
program device SMBus base address. These inputs have internal pull-up
resistors to VSTBY[A/B].
SMBus Data: Bidirectional SMBus data line.
SMBus Clock: Input.
Interrupt Output: Open-drain, active-low. Asserted whenever a power fault
is detected if the INTMSK bit (CS Register Bit D[3]) is a logical "0". This
output is cleared by performing an "echo reset" to the appropriate fault bit(s)
in the STAT[A/B] and/or CS registers. This pin requires an external pull-up
resistor to V_STBY.
3 Pins, IC Ground Connections: Tie directly to the system’s analog GND
plane directly at the device.
Connecting this pin to GND through a 110kΩ, 1% resistor will provide a
significant improvement in timeout duration accuracy for slow overcurrent
faults on Slot A and Slot B. If left floating (NC), overcurrent timeout duration
accuracy is determined by the specification for V_FILTER and I_FILTER. Please
see the “Circuit Breaker Function” text in the “Functional Description” section
for more detail.
Reserved: Make no external connections to these pins.
March 2005
6
M9999-033105