LT1641-2_15 Datasheet, PDF (1/12 Pages) Linear Technology – Positive High Voltage Hot Swap Controllers

LT1641-1/LT1641-2
Positive High Voltage
Hot Swap Controllers
FEATURES
■ _{Allows Safe Board Insertion and Removal from a}
Live Backplane
■ _{Controls Supply Voltage from 9V to 80V}
■ _{Programmable Analog Foldback Current Limiting}
■ _{High Side Drive for an External N-Channel}
■ _{Latched Operation Mode (LT1641-1)}
■ _{Automatic Retry (LT1641-2)}
■ _{User Programmable Supply Voltage Power-Up Rate}
■ _{Undervoltage Lockout}
■ _{Overvoltage Protection}
■ _{Both are available in 8-Lead SO Package}
U
APPLICATIO S
■ _{Hot Board Insertion}
■ _{Electronic Circuit Breaker}
■ _{Industrial High Side Switch/Circuit Breaker}
■ _{24V/48V Industrial/Alarm Systems}
DESCRIPTIO
The LT^®1641-1/LT1641-2 are 8-pin Hot Swap^TM control-
lers that allow a board to be safely inserted and removed
from a live backplane. Using an external N-channel pass
transistor, the board supply voltage can be ramped up at
a programmable rate. A high side switch driver controls an
N-channel gate for supply voltages ranging from 9V to
80V.
The chips feature a programmable analog foldback cur-
rent limit circuit. If the chips remain in current limit for
more than a programmable time, the N-channel pass
transistor is either latched off (LT1641-1) or is set to
automatically restart after a time-out delay (LT1641-2).
The PWRGD output indicates when the output voltage,
sensed by the FB pin, is within tolerance. The ON pin
provides programmable undervoltage lockout.
The LT1641-1/LT1641-2 are available in the 8-lead SO
package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
V_IN
24V
SHORT
PIN
24V Input Voltage Application
R_S
0.01Ω
Q1
IRF530
R1
49.9k
1%
D1
R5
CMPZ
10Ω
5248B
5%
C1
R6, _10nF
1k, 5%
*SMAT70A
R2
3.4k
1%
V_CC SENSE GATE
ON
FB
LT1641-1/LT1641-2
TIMER
PWRGD
GND
V_OUT
R3
C_L
59k
1%
R7
24k
5%
R4
3.57k
1%
PWRGD
GND
*DIODES, INC.
C2
0.68µF
1641-1 TA01
164112fc
1