SC4150 Datasheet, PDF (1/12 Pages) Semtech Corporation – Negative Voltage Hot Swap Controller

POWER MANAGEMENT
Description
The SC4150 is a negative voltage hotswap controller that
allows the insertion of line cards into a live backplane.
The inrush current is programmable and closed loop op-
eration limits the maximum current even under short cir-
cuit conditions. A built in timing circuit prevents false shut-
down. The signal from the drain voltage is fed to the
timer, providing safety for the MOSFET when in linear
mode. The SC4150 latches off under abnormal condi-
tion and attempts to restart after a time out period.
The device comes in two options, PWRGD (SC4150H)
and PWRGD (SC4150L). These signals can be directly
used to enable power modules.
SC4150
Negative Voltage
Hot Swap Controller
Features
‹ Programmable slew of the inrush current when
used for hot insertion in the negative 24V and 48V
backplane
‹ Closed loop operation limits the maximum current
even in short circuit condition
‹ Built in timer prevents false shutdown, when the
closed loop operation limits the current.
‹ Sensing the drain voltage allows for immediate
shutdown in short circuit condition, where current
spikes and noise is ignored.
‹ Power good signal
‹ Input UVLO and OVLO sensing
‹ SO-8 package
Applications
‹ Central office switching
‹ -48V Distributed power systems
‹ Power supply hotswap & inrush control
Typical Application Circuit
GND
PWRGD/PWRGD
GND(remote)
R1
562k
R2
9.31k
R3
10.2k
-- 48V
U1
SC4150
1
PWRGD /PWRGD
VCC
8
2
OV
DRAIN
7
3
UV
GATE
6
4
VEE
SENSE
5
C1
0.1
VVeEeE
R6
C4
18k
3.3nF
C5
150
C2
0.001
R4
0.01
C3
0.33
R5
10
Q1
Figure 1
Revision: April 14, 2004
1
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