1
LTC1645
1645fa
Dual-Channel Hot Swap
Controller/Power Sequencer
The LTC
?/DIV>
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.
s
Hot Board Insertion
s
Power Supply Sequencing
s
Electronic Circuit Breaker
s
Allows Safe Board Insertion and Removal from a
Live Backplane
s
Programmable Power Supply Sequencing
s
Programmable Electronic Circuit Breaker
s
User-Programmable Supply Voltage Power-Up and
Power-Down Rate
s
High Side Drivers for External N-Channel FETs
s
Controls Supply Voltages from 1.2V to 12V
s
Ensures Proper Power-Up Behavior
s
Undervoltage Lockout
s
Glitch Filter Protects Against Spurious RESET Signals
s
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.
5V and 3.3V Hot Swap
5V and 3.3V Hot Swap Waveforms
ON
5V/DIV
GATEn
10V/DIV
V
OUT2
5V/DIV
V
OUT1
5V/DIV
0.005&*
IRF7413
IRF7413
0.005&*
10&
10&
10k
C
LOAD2
C
LOAD1
V
OUT1
5V
5A
V
OUT2
3.3V
5A
1645 TA01
0.01礔
25V
0.01礔
25V
ON
V
IN2
V
IN1
ON
GND
GND
PLUG-IN CARD
BACKPLANE
SENSE1
V
CC2
GATE1
SENSE2 GATE2
LTC1645
(8-LEAD)
+
+
V
CC1
*LRF1206-01-R005-J (IRC)
FEATURES
DESCRIPTIO
APPLICATIO S
TYPICAL APPLICATIO