LT1640L Datasheet, PDF (1/12 Pages) Linear Technology – Negative Voltage Hot Swap Controller

FEATURES
s _{Allows Safe Board Insertion and Removal}
from a Live – 48V Backplane
s _{Operates from –10V to – 80V}
s _{Programmable Inrush Current}
s _{Programmable Electronic Circuit Breaker}
s _{Programmable Overvoltage Protection}
s _{Programmable Undervoltage Lockout}
s _{Power Good Control Output}
U
APPLICATIONS
s _{Central Office Switching}
s _{– 48V Distributed Power Systems}
s _{Negative Power Supply Control}
LT1640L/LT1640H
Negative Voltage
Hot Swap Controller
DESCRIPTION
The LT^®1640L/LT1640H is an 8-pin, negative voltage Hot
Swap^TM controller that allows a board to be safely inserted
and removed from a live backplane. Inrush current is
limited to a programmable value by controlling the gate
voltage of an external N-channel pass transistor. The pass
transistor is turned off if the input voltage is less than the
programmable undervoltage threshold or greater than the
overvoltage threshold. A programmable electronic circuit
breaker protects the system against shorts. The PWRGD
(LTC1640L) or PWRGD (LTC1640H) signal can be used to
directly enable a power module. The LT1640L is designed
for modules with a low enable input and the LT1640H for
modules with a high enable input.
The LT1640L/LT1640H is available in 8-pin PDIP and SO
packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
TYPICAL APPLICATION
GND
UV = 37V
OV = 71V
R4
562k
1%
R5
9.09k
1%
R6
10k
1%
3
UV
2
OV
V_EE
4
SENSE
5
– 48V
R1
0.02Ω
5%
8
V_DD
LT1640L
1
PWRGD
GATE
DRAIN
C1
33nF
24V
6
7
R2 _R3
10Ω _10k C2
5% _5% 3.3nF
100V
Q1
IRF530
C3 +
0.1µF
100V
C4
100µF
100V
2
1
ON/OFF
V_IN+
V_OUT+
SENSE ⁺
9
8
7
+
TRIM
SENSE ^{– 6}
4 _VIN–
V_OUT– ⁵
5V
C5
100µF
16V
LUCENT
JW050A1-E
1640 TA01
Input Inrush Current
CONTACT
BOUNCE
1640 F07b
1