X80010 Datasheet, PDF (14/25 Pages) Intersil Corporation – Penta-Power Sequence Controller with Hot swap and System Management

X80010, X80011, X80012, X80013
Pin Descriptions (Continued)
PIN NAME
DESCRIPTION
21 RESET RESET Output. This open drain pin is an active LOW output. This pin will be active until PWRGD goes active and the power
sequencing is complete. This pin will be released after a programmable delay.
22
NA1 Not Available. Do not connect to this pin.
23
MRC Manual Reset Input Cold-side. Pulling the MRC pin HIGH initiates a system side RESET. The MRC signal must be held HIGH
for 5µs. It has an internal pulldown resistor. (>10mΩ typical)
24
NC
No Connect. No internal connections.
25
V_EE
Negative Supply Voltage Input.
26
NC
No Connect. No internal connections.
27
FAR Failure After Re-try (FAR) output signal. Failure After Re-try (FAR) is asserted after a number of retries. Used for Overcurrent
and hardshort detection.
28 BATT-ON Battery On Input. This input signals that the battery backup (or secondary supply) is supplying power to the backplane. It has
an internal pulldown resistor. (>10mΩ typical)
29 PWRGD Power Good Output. This output pin enables a power module.
30
IGQ1 Gate Current Quick Select Bit 1 Input. This pin is used to change the gate current drive and is intended to allow for current
ramp rate control of the gate pin of an external FET. It has an internal pulldown resistor. (>10mΩ typical)
31
IGQ0 Gate Current Quick Select Bit 0 Input. This pin is used to change the gate current drive and is intended to allow for current
ramp rate control of the gate pin of an external FET. It has an internal pulldown resistor. (>10mΩ typical)
32
MRH Manual Reset Input Hot-side. Pulling the MRH pin LOW initiates a GATE pin reset (GATE pin pulled LOW). The MRH signal
must be held LOW for 5µs (minimum).
Functional Description
Hot Circuit Insertion
When circuit boards are inserted into a live backplane, the
bypass capacitors at the input of the board’s power module
or DC/DC converter can draw huge transient currents as
they charge up (See Figure 30). This transient current can
cause permanent damage to the board’s components and
cause transients on the system power supply.
(DC/DC converter) off until the backplane input voltage is
stable and within tolerance.
-48V
Return
R5
30k
1%
R4
182K
1%
UV=37V
V_UV/OV
OV=71V
V_DD
X80010
X80011
X80012
X80013
DC/DC
Converter
R6
10K
1%
-48V
V_{EE SENSE GATE} DRAIN
Rs
0.02Ω
5%
I_inrush
0.1µF
4.7k
100
3.3n
Q1 _IRFR120
100K
DC/DC
Converter
-48V
FIGURE 30. TYPICAL -48V HOTSWAP APPLICATION CIRCUIT
The X80010 is designed to turn on a board’s supply voltage
in a controlled manner (see Figure 31), allowing the board to
be safely inserted or removed from a live backplane. The
device also provides undervoltage, overvoltage and
overcurrent protection while keeping the power module
14
FIGURE 31. TYPICAL INRUSH WITH GATE SLEW RATE
CONTROL
Overvoltage and Undervoltage Shutdown
The X80010 provides overvoltage and undervoltage
protection circuits. When an overvoltage (V_OV) or
undervoltage (V_UV1 and V_UV2) condition is detected, the
GATE pin immediately pulls low. The undervoltage threshold
V_UV1 applies to the normal operation with a mains supply.
The undervoltage threshold V_UV2 assumes the system is
powered by a battery. When using a battery backup, the
FN8149.0
January 13, 2005