LTC4230 Datasheet, PDF (1/36 Pages) Linear Technology – Triple Hot Swap Controller with Multifunction Current Control

LTC4230
Triple Hot Swap Controller
with Multifunction Current Control
FEATURES
DESCRIPTIO
s _{Allows Safe Board Insertion and Removal}
from a Live Backplane
s _{Controls Three Supply Voltages from 1.7V to 16.5V}
with V_CC1 ≥ V_CC2 ≥ V_CC3
s _{Programmable Soft-Start with Inrush Current}
Limiting, No External Gate Capacitor Required
s _{Faster Turn-Off Time with No Gate Capacitor}
s _{Dual Level Overcurrent Fault Protection}
s _{Programmable Overcurrent Response Time}
s _{Programmable Overvoltage Protection}
s _{Automatic Retry or Latched Mode Operation}
s _{Independent N-Channel FET High Side Drivers}
s _{User-Programmable Supply Voltage Power-Up Rate}
s _{FBn Pin Monitors VOUTn and Signals RESETn}
s _{Glitch Filter Eliminates Spurious RESETn Signals}
U
APPLICATIO S
s _{Electronic Circuit Breaker}
s _{Hot Board Insertion and Removal (Either On}
Backplane or On Removable Card)
s _{Industrial High Side Switch/Circuit Breaker}
The LTC^®4230 is a 3-channel Hot Swap^TM controller that
allows a board to be safely inserted and removed from a
live backplane. Internal high side switch drivers control
the gates of external N-channel MOSFETs for supply
voltages ranging from 1.7V to 16.5V. The LTC4230 pro-
vides soft-start and inrush current limiting during the
programmable start-up period.
On-chip current limit comparators provide dual level
circuit breaker protection. The slow comparators trip at
V_CCn – 50mV and activate in 10µs or are programmed by
an external filter capacitor. The fast comparators trip at
V_CCn – 150mV and typically respond in 500ns.
Each FBn pin monitors its own output supply voltage and
signals its RESET pin. The ON pin turns the chip on and
off and can be used for a reset function. The LTC4230 also
provides additional functions including fault indication,
autoretry or latchoff modes, programmable current limit
response time based on the FAULT and FILTER pins’
functionality.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
BACKPLANE PCB EDGE
CONNECTOR CONNECTOR
V_CC1
3.3V
(FEMALE)
(MALE)
LONG
V_CC2
2.5V
LONG
V_CC3
1.8V
LONG
Z1***
RX1
10Ω
CX1
100nF
3-Channel Hot Swap Controller
R_SENSE1
0.007Ω
Q1
IRF7413
R_SENSE2
0.007Ω
Q2
IRF7413
R_SENSE3
0.007Ω
Q3
IRF7413
Z2***
RX3
10Ω
RX2
10Ω
Z3***
CX3
100nF
CX2
100nF
6
V_CC1
7
8
SENSE 1 GATE 1
16
17
V_CC2 SENSE 2
18 5
GATE 2 V_CC3
4
3
SENSE 3 GATE 3
1
FB3
R8
5.1k
R7
R9 ^10k
12k
FAULT
GND
PCB CONNECTION SENSE
SHORT
R1 R2
10k 10k
SHORT
LONG
* SYSTEM ON TIME: 6.2ms
**CIRCUIT BREAKER RESPONSE TIME: 19.5µs
***OPTIONAL
Z1, Z2, Z3: SMAJ10
C_TIMER*
0.1µF
C_FILTER**
15pF
15
ON
13
FAULT
14
GND
12
TIMER
11
FILTER
LTC4230
2
RESET 3
R10
20
11k
FB2
R11
12k
19
RESET 2
9
RESET 1
10
FB1
V_OUT1
3.3V
5A
V_OUT2
2.5V
5A
V_OUT3
1.8V
5A
RESET 3
R6
R5
10k
10k
RESET 2
RESET 1
R12
18k
R13
12k
4230 TA01
4230f
1