X80070 Datasheet, PDF (9/14 Pages) Intersil Corporation – Hot Swap Controller with Advanced Fault Protection and Voltage Refulator Output

X80070, X80071, X80072, X80073
PIN CONFIGURATION
X80070
20L QFN Package
V_RGO
DNC
NA2
NA2
V_DD
20 19 18 17 16
1
15
2
14
3 _{5mm x 5mm}13
4
12
5
11
6 7 8 9 10
FAR
NA2
NA1
NA1
DNC
TOP VIEW
NA1 pins connect to V_RGO
NA2 pins connect to V_EE
PIN DESCRIPTIONS
Pin Name
Description
1
V_RGO Regulated 5V output. Used to pull-up
user programmable inputs IGQ0, IGQ1,
BATT-ON and MRH (if needed).
2
DNC Pin not used. Do not connect to this pin.
3
NA2 Not Available. Connect to V_EE.
4
NA2 Not Available. Connect to V_EE.
5
V_DD Positive Supply Voltage Input.
6
V_EE Negative Supply Voltage Input.
7 V_UV/OV Analog Undervoltage and Overvoltage
Input. Turns off the external N-channel
MOSFET when there is an undervoltage
or overvoltage condition.
8 SENSE Circuit Breaker Sense Input. This input
pin detects the overcurrent condition.
9 GATE FET Gate Drive. This pin supplies the cur-
rent to turn on the FET.
10 DNC Pin not used. Do not connect to this pin.
11 DNC Pin not used. Do not connect to this pin.
12
NA1 Not Available. Connect to V_RGO.
13
NA1 Not Available. Connect to V_RGO.
14
NA2 Not Available. Connect to V_EE.
15 FAR Failure After Re-try (FAR) output signal.
16 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)
17 PWRGD Power Good Output. This output pin en-
ables a power module.
PIN DESCRIPTIONS (Continued)
Pin Name
Description
18 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)
19 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)
20
MR Manual Reset. Pulling the MR pin LOW
initiates a GATE pin reset (GATE pin
pulled LOW). The MR signal must be held
LOW for 5µsecs (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. This transient current can cause permanent
damage to the board’s components and cause transients on
the system power supply.
The X80070 is designed to turn on a board’s supply voltage in a
controlled manner (see Figure 5), 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 (dc-dc converter)
off until the backplane input voltage is stable and within
tolerance.
Figure 5. Typical Inrush with Gate Slew Rate Control
I_INRUSH
V_GATE
V_{FET_DRAIN}
PWRGD
9
FN8150.0
March 15, 2005