LM5069MMX-1/NOPB National Semiconductor, LM5069MMX-1/NOPB Datasheet - Page 19

• Manufacturer Part Number: LM5069MMX-1/NOPB
• Description: IC CTLR HOT SWAP 48V 10-MSOP
• Manufacturer: National Semiconductor
• Type: Hot-Swap Controllerr

Specifications of LM5069MMX-1/NOPB

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 9 V ~ 80 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
• For Use With: LM5069EVAL - BOARD EVALUATION LM5069
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM5069MMX-1

•
System Considerations
A) Continued proper operation of the LM5069 hot swap circuit
requires capacitance be present on the supply side of the
connector into which the hot swap circuit is plugged in, as
depicted in Figure 2. The capacitor in the “Live Backplane”
section is necessary to absorb the transient generated when-
ever the hot swap circuit shuts off the load current. If the
capacitance is not present, inductance in the supply lines will
generate a voltage transient at shut-off which can exceed the
The board’s edge connector can be designed to shut off
the LM5069 as the board is removed, before the supply
voltage is disconnected from the LM5069. In Figure 17 the
voltage at the UVLO pin goes to ground before V
FIGURE 18. Output Diode Required for Inductive Loads
FIGURE 17. Recommended Board Connector Design
SYS
is
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absolute maximum rating of the LM5069, resulting in its de-
struction.
B) If the load powered via the LM5069 hot swap circuit has
inductive characteristics, a diode is required across the
LM5069’s output. The diode provides a recirculating path for
the load’s current when the LM5069 shuts off that current.
Adding the diode prevents possible damage to the LM5069
as the OUT pin will be taken below ground by the inductive
load at shutoff. See Figure 18.
removed from the LM5069 due to the shorter edge
connector pin. When the board is inserted into the edge
connector, the system voltage is applied to the LM5069’s
VIN pin before the UVLO voltage is taken high.
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