LTC1422
Hot Swap Controller
FEATURES DESCRIPTIO
TM
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Allows Safe Board Insertion and Removal The LTC 1422 is an 8-pin Hot Swap controller that
from a Live Backplane allows a board to be safely inserted and removed from a
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System Reset Output with Programmable Delay live backplane. Using an external N-channel pass transis-
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Programmable Electronic Circuit Breaker tor, the board supply voltage can be ramped up at a
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User-Programmable Supply Voltage Power-Up Rate programmable rate. A high side switch driver controls the
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High Side Driver for an External N-Channel FET N-channel gate for supply voltages ranging from 2.7V to
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Controls Supply Voltages from 2.7V to 12V 12V.
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Undervoltage Lockout
A programmable electronic circuit breaker protects
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Soft Reset Input
against shorts. The RESET output can be used to generate
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Glitch Filter on RESET
a system reset when the supply voltage falls below a
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Available in 8-Pin Narrow PDIP and SO Packages
programmable voltage. The ON pin can be used to cycle
the board power or to generate a soft reset.
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APPLICATIO S
The LTC1422 is available in 8-pin PDIP and SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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Hot Board Insertion
Hot Swap is a trademark of Linear Technology Corporation.
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Electronic Circuit Breaker
TYPICAL APPLICATIO
5V Hot Swap
Q1
R1
0.005 MTB50N06V
V V
OUT
CC
+ 5V
C
LOAD
R2 R3
10 6.81k
5% 1%
C1
8 76
0.1F
V SENSE GATE
CC
2 5
ON/RESET ON FB
R4
LTC1422
2.43k
1
RESET 1% P
TIMER GND
RESET
34
C2
0.33F
GND
1422 TA01
BACKPLANE PLUG-IN CARD
1422fb
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CONNECTOR 2
CONNECTOR 1
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ULTC1422
ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER I FOR ATIO
(Note 1)
ORDER PART
TOP VIEW
Supply Voltage (V ) ........................................... 13.2V
CC
NUMBER
Input Voltage (TIMER, SENSE) ... 0.3V to (V + 0.3V)
CC RESET 1 8
V
CC
Input Voltage (FB, ON)........................... 0.3V to 13.2V
ON 2 7 SENSE
LTC1422CN8
Output Voltage (RESET) ........................... 0.3V to 20V
TIMER 3 6 GATE
LTC1422CS8
Output Voltage (GATE) ............................. 0.3V to 20V
GND 4 5 FB
LTC1422IN8
Operating Temperature Range
LTC1422IS8
N8 PACKAGE S8 PACKAGE
8-LEAD PDIP 8-LEAD PLASTIC SO
LTC1422C ............................................... 0C to 70C
T = 150C, = 130C/W (N)
LTC1422I........................................... 40C to 85C JMAX JA S8 PART MARKING
T = 150C, = 150C/W (S)
JMAX JA
Storage Temperature Range ................ 65C to 150C
1422
Lead Temperature (Soldering, 10 sec)................. 300C
1422I
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25C. V = 5V unless otherwise noted.
A CC
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
DC Characteristics
I V Supply Current ON = V l 0.65 1.00 mA
CC CC CC
V V Undervoltage Lockout l 2.40 2.47 2.55 V
LKO CC
V V Undervoltage Lockout Hysteresis 120 mV
LKH CC
V FB Pin Voltage Threshold l 1.220 1.232 1.244 V
FB
V FB Pin Threshold Line Regulation 3V V 12V l 0.5 2.5 mV
FB CC
V FB Pin Voltage Threshold Hysteresis 2.0 mV
FBHST
V TIMER Pin Voltage Threshold l 1.208 1.232 1.256 V
TM
V TIMER Pin Threshold Line Regulation 3V V 12V l 215 mV
TM CC
V TIMER Pin Voltage Threshold Hystersis 45 mV
TMHST
I TIMER Pin Current Timer On, GND V 1.5V l 2.5 2.0 1.5 A
TM TIMER
Timer Off, V = 1.5V 10 mA
TIMER
V Circuit Breaker Trip Voltage V = (V V ) l 44 50 64 mV
CB CB CC SENSE
I GATE Pin Output Current Charge Pump On, V = GND l 12 10 8 A
CP GATE
Charge Pump Off, V = V 10 mA
GATE CC
V External N-Channel Gate Drive V V l 10 12 14 V
GATE GATE CC
V ON Pin Threshold High l 1.25 1.30 1.35 V
ONHI
V ON Pin Threshold Low l 1.20 1.23 1.26 V
ONLO
V ON Pin Hysteresis 80 mV
ONHYST
V Output Low Voltage RESET, I = 3mA l 0.14 0.4 V
OL O
I Logic Output Pull-Up Current RESET = GND 12 A
PU
t Soft Reset Time l 22 30 48 s
RST
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
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