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SC4150

Negative Voltage

Hot Swap Controller

POWER MANAGEMENT

Revision: April 14, 2004

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

Central office switching

-48V Distributed power systems

Power supply hotswap & inrush control

Description

Features

Applications

Typical Application Circuit

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.

Figure 1

Q1

C3

0.33

C5

150

GND

-- 48V

R5

10

R1

562k

R3

10.2k

R4

0.01

R6

18k

R2

9.31k

C4

3.3nF

DRAIN

7

UV

3

VEE

4

GATE

6

PWRGD

1

SENSE

5

VCC

8

OV

2

U1

SC4150

GND(remote)

C2

0.001

C1

0.1

Vee

PWRGD/PWRGD

/PWRGD

VEE