lm5067mmx-2 National Semiconductor Corporation, lm5067mmx-2 Datasheet - Page 15

• Manufacturer Part Number: lm5067mmx-2
• Description: Negative Hot Swap / Inrush Current Controller With Power Limiting
• Manufacturer: National Semiconductor Corporation

B) Turn-on with power limit and current limit: The power
dissipation limit in Q1 (P
the PWR pin, and the current sense resistor R
FIGURE 9. Load Draws Current During Turn-On
FET(LIM)
) is defined by the resistor at
FIGURE 10. MOSFET Power Up Waveforms
30030939
S
. See the
15
Power Limit Threshold section. If the current limit threshold
(I
threshold at maximum V
ates initially in power limit mode when the V
and then transitions to current limit mode as the current in-
creases to I
the load (R
output voltage to reach its final value is approximately equal
to:
For example, if V
P
rent level (I
Period must be set longer than t
LIM
FET(LIM)
) is higher than the current defined by the power limit
= 20W, t
L
LIM
) is not connected during turn-on, the time for the
P
) is approximately 0.42A. The Fault Timeout
as V
ON
SYS
DS
calculates to
= -48V, C
decreases. See Figure 10b. Assuming
DS
(P
FET(LIM)
L
≊
= 1000 µF, I
ON
68 ms, and the initial cur-
30030941
.
/V
SYS
) the circuit oper-
DS
LIM
of Q1 is high,
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= 1A, and