lm25061pmmx-2 National Semiconductor Corporation, lm25061pmmx-2 Datasheet - Page 18

• Manufacturer Part Number: lm25061pmmx-2
• Description: Positive Low Voltage Power Limiting Hot Swap Controller
• Manufacturer: National Semiconductor Corporation

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System Considerations
A) Continued proper operation of the LM25061 hot swap cir-
cuit 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 Power Source”
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
absolute maximum rating of the LM25061, resulting in its de-
struction.
FIGURE 17. Output Diode Required for Inductive Loads
FIGURE 16. Recommended Board Connector Design
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B) If the load powered by the LM25061 hot swap circuit has
inductive characteristics, a Schottky diode is required across
the LM25061’s output, along with some load capacitance.
The capacitance and the diode are necessary to limit the
negative excursion at the OUT pin when the load current is
shut off. If the OUT pin transitions more than 0.3V negative
the LM25061 will internally reset, interfering with the latch-off
feature of the LM25061-1, or the restart cycle of the
LM25061-2. See Figure 17.
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