LTC1645
Dual-Channel Hot Swap
Controller/Power Sequencer
FEATURES
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DESCRIPTIO
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Allows Safe Board Insertion and Removal from a
Live Backplane
Programmable Power Supply Sequencing
Programmable Electronic Circuit Breaker
User-Programmable Supply Voltage Power-Up and
Power-Down Rate
High Side Drivers for External N-Channel FETs
Controls Supply Voltages from 1.2V to 12V
Ensures Proper Power-Up Behavior
Undervoltage Lockout
Glitch Filter Protects Against Spurious RESET Signals
APPLICATIO S
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Hot Board Insertion
Power Supply Sequencing
Electronic Circuit Breaker
The LTC
®
1645 is a 2-channel Hot Swap
TM
controller that
allows a board to be safely inserted and removed from a
live backplane. Using external N-channel pass transistors,
the supply voltages can be ramped at a programmable
rate. Two high side switch drivers control the N-channel
gates for supply voltages ranging from 1.2V to 12V. The
two channels can be set to ramp up and down separately,
or they can be programmed to rise and fall simultaneously,
ensuring power supply tracking at the two outputs.
Programmable electronic circuit breakers protect against
shorts at either output. The RESET output can be used to
generate a system reset when a supply voltage falls below
a user-programmed voltage. An additional spare com-
parator is available for monitoring a second supply
voltage.
The LTC1645 is available in the 8- and 14-pin SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
V
IN2
5V and 3.3V Hot Swap
0.005Ω* IRF7413
5V and 3.3V Hot Swap Waveforms
+
V
OUT2
3.3V
5A
C
LOAD2
V
OUT1
5V
5A
C
LOAD1
0.005Ω*
V
IN1
IRF7413
ON
5V/DIV
+
10Ω
10Ω
0.01µF
25V
7
8
5
10k
GND
4
1645 TA01
GATEn
10V/DIV
CONNECTOR 2
CONNECTOR 1
0.01µF
25V
1
2
3
6
V
OUT2
5V/DIV
SENSE1 GATE1
V
CC1
ON
V
CC2
SENSE2 GATE2
LTC1645
(8-LEAD)
V
OUT1
5V/DIV
ON
GND
BACKPLANE PLUG-IN CARD
*LRF1206-01-R005-J (IRC)
U
U
U
1
LINER [ LINEAR TECHNOLOGY ]
