FEATURES
s
s
LTC4230
Triple Hot Swap Controller
with Multifunction Current Control
DESCRIPTIO
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.
s
s
s
s
s
s
s
s
s
s
Allows Safe Board Insertion and Removal
from a Live Backplane
Controls Three Supply Voltages from 1.7V to 16.5V
with V
CC1
≥
V
CC2
≥
V
CC3
Programmable Soft-Start with Inrush Current
Limiting, No External Gate Capacitor Required
Faster Turn-Off Time with No Gate Capacitor
Dual Level Overcurrent Fault Protection
Programmable Overcurrent Response Time
Programmable Overvoltage Protection
Automatic Retry or Latched Mode Operation
Independent N-Channel FET High Side Drivers
User-Programmable Supply Voltage Power-Up Rate
FBn Pin Monitors V
OUTn
and Signals RESETn
Glitch Filter Eliminates Spurious RESETn Signals
APPLICATIO S
s
s
s
Electronic Circuit Breaker
Hot Board Insertion and Removal (Either On
Backplane or On Removable Card)
Industrial High Side Switch/Circuit Breaker
TYPICAL APPLICATIO
BACKPLANE
CONNECTOR
(FEMALE)
V
CC1
3.3V
V
CC2
2.5V
V
CC3
1.8V
PCB EDGE
CONNECTOR
(MALE)
LONG
LONG
LONG
Z1***
3-Channel Hot Swap Controller
R
SENSE1
0.007Ω
Q1
IRF7413
R
SENSE2
0.007Ω
Q2
IRF7413
R
SENSE3
0.007Ω
RX2
10Ω
Q3
IRF7413
V
OUT1
3.3V
5A
V
OUT2
2.5V
5A
V
OUT3
1.8V
5A
R8
5.1k
R9
12k
RESET 3
2
R10
11k
R11
12k
RESET 2
GND
RESET 1
TIMER
FILTER
FB1
10
19
9
R12
18k
R13
12k
4230 TA01
RX1
10Ω
CX1
100nF
RX3
10Ω
CX3
100nF
Z3***
CX2
100nF
Z2***
6
V
CC1
7
SENSE 1
8
GATE 1
16
V
CC2
17
SENSE 2
18
5
GATE 2 V
CC3
SENSE 3 GATE 3
FB3
1
PCB CONNECTION SENSE
SHORT
R1
10k
R2
10k
15
FAULT
GND
SHORT
LONG
13
14
12
11
* SYSTEM ON TIME: 6.2ms
**CIRCUIT BREAKER RESPONSE TIME: 19.5µs
***OPTIONAL
Z1, Z2, Z3: SMAJ10
C
TIMER
*
0.1µF
C
FILTER
**
15pF
LTC4230
ON
FAULT
U
U
U
4
3
R7
10k
RESET 3
FB2
20
R6
10k
R5
10k
RESET 2
RESET 1
4230f
1
LTC4230
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
FB3
RESET 3
GATE 3
SENSE 3
V
CC3
V
CC1
SENSE 1
GATE 1
RESET 1
1
2
3
4
5
6
7
8
9
20 FB2
19 RESET 2
18 GATE 2
17 SENSE 2
16 V
CC2
15 ON
14 GND
13 FAULT
12 TIMER
11 FILTER
Supply Voltage (V
CCn
) ............................................. 17V
SENSEn Pins ............................... – 0.3V to (V
CC
+ 0.3V)
FBn, ON Pins ............................... – 0.3V to (V
CC
+ 0.3V)
TIMER Pin ...................................................– 0.3V to 2V
GATEn Pins ........................... Internally Limited (Note 3)
RESETn, FAULT, FILTER Pins ....................– 0.3V to 17V
Operating Temperature Range
LTC4230C ............................................... 0°C to 70°C
LTC4230I ............................................ – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC4230CGN
LTC4230IGN
FB1 10
GN PACKAGE
20-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 95°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
CC
PARAMETER
Supply Voltage (V
CC1
)
Supply Voltage (V
CC2
)
Supply Voltage (V
CC3
)
Supply Current (I
CC1
)
Supply Current (I
CC2
)
Supply Current (I
CC3
)
Undervoltage Lockout , Channel 1
Undervoltage Lockout , Channel 2
Undervoltage Lockout , Channel 3
Undervoltage Lockout Hysteresis, Channel 1
Undervoltage Lockout Hysteresis, Channel 2
Undervoltage Lockout Hysteresis, Channel 3
FBn Pin Input Current
ON Pin Input Current
Input Current for SENSEn
Circuit Breakern Trip Voltage
GATEn Pull-Up Current
Normal GATEn Pull-Down Current
Fast GATEn Pull-Down Curent
I
LEAK
RESETn Leakage Current
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
CC1
= 3.3V, V
CC2
= 2.5V,V
CC3
= 1.8V unless otherwise noted. (Note 2)
CONDITIONS
V
CC2
≤
V
CC1
V
CC3
≤
(V
CC1
– 1V)
ON = V
CC1
, FB1 = High
ON = V
CC1
, FB2 = High
ON = V
CC1
, FB3 = High
V
CC1
Low to High Transition
V
CC2
Low to High Transition
V
CC3
Low to High Transition
q
q
q
q
q
q
q
q
q
MIN
2.700
2.375
1.700
TYP
MAX
16.5
16.5
15.5
UNITS
V
V
V
mA
µA
µA
V
V
V
mV
mV
mV
I
CC
1.8
75
65
2.15
1.98
1.09
2.35
2.15
1.19
100
45
35
3
150
150
2.52
2.32
1.29
V
LKO1
V
LKO2
V
LKO3
V
LKOHST1
V
LKOHST2
V
LKOHST3
I
IN, FBn
I
IN, ON
I
IN, SENSEn
V
CB(FAST)
V
CB(SLOW)
I
GATEn , UP
I
GATEn , DN
0V
≤
V
FBn
≤
V
CCn
0V
≤
V
ON
≤
V
CC1
0V
≤
V
SENSEn
≤
V
CCn
Fast Comparator
Slow Comparator
Charge Pump On, 0
≤
V
GATEn
< 0.2V
ON Low, V
GATEn
= 5V
FAULT Latched and Circuit Breaker
Tripped or in UVLO, V
GATEn
= 5V
V
RESETn
= 15V, Pull-Down Device Off
q
q
q
q
q
q
±0.1
±0.1
±0.1
135
40
–12.5
150
50
–10
200
16
±10
±10
±15
165
60
–6.5
q
±0.1
±2.5
2
U
µA
µA
µA
mV
mV
µA
µA
mA
µA
4230f
W
U
U
W W
W
LTC4230
ELECTRICAL CHARACTERISTICS
SYMBOL
∆V
GATEn
PARAMETER
External N-Channel Gate Drive
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
CC1
= 3.3V, V
CC2
= 2.5V,V
CC3
= 1.8V unless otherwise noted. (Note 2)
CONDITIONS
V
GATE1, 2
– V
CC1, 2
(for V
CC1, 2
= 2.7V, V
CC3
= V
CC1
– 1V)
V
GATE3
– V
CC3
(for V
CC1, 2
= 2.7V, V
CC3
= V
CC1
– 1V)
V
GATE1, 2
– V
CC1, 2
(for V
CC1, 2
= 3.3V, V
CC3
= V
CC1
– 1V)
V
GATE3
– V
CC3
(for V
CC1, 2
= 3.3V, V
CC3
= V
CC1
– 1V)
V
GATEn
– V
CCn
(for V
CC1, 2
= 5V, V
CC3
= V
CC1
– 1V)
V
GATEn
– V
CCn
(for V
CC1, 2
= 12V or 15V,
V
CC3
= V
CC1
– 1V)
q
q
q
q
q
q
MIN
4.5
5.5
5
6
9
7
TYP
MAX
8
9
10
11
16
18
UNITS
V
V
V
V
V
V
V
V
GATEn, 0V
V
FBn
∆V
FBn
V
FBn, HST
V
ONHI
V
ONLO
V
ONHST
I
FILTER
V
FILTER
V
FILTERHST
I
TMR
GATEn Overvoltage Lockout
Threshold
FBn Low Threshold Voltage
FBn Line Regulation
FBn Hysteresis
ON High Threshold Voltage
ON Low Threshold Voltage
ON Hysteresis
FILTER Pull-Up Current
FILTER Pull-Down Current
FILTER Threshold
FILTER Threshold Hysteresis
TIMER Pull-Up Current
TIMER Pull-Down Current
TIMER Threshold
FAULT Low Threshold Voltage
FAULT Hysteresis
FAULT Pull-Up Current
Output Low Voltage
Output Low Voltage
Fast COMPn Trip to
GATEn Discharging
Slow Comparator Trip to
FILTER High and FAULT Latched
FILTER Comparator Trip to
GATEn Discharging
FAULT Low to GATE Discharging
Circuit Breaker Reset Time
Turn-Off Time
I
FAULT
= 1.6mA, V
CC1
= 5V
I
RESETn
= 1.6mA, V
CC1
= 5V
V
CB
= 0mV to 200mV Step
V
CB
= 0mV to 100mV Step, FILTER Floating
10nF at FILTER Pin to GND
V
FILTER
= 0V to 5V
V
FAULT
= 5V to 0V
ON Held Low to Guarantee FAULT High
ON Goes Low to GATEn Off
q
q
q
q
0.25
FBn High to Low Transition
2.7V
≤
V
CC1
≤
16.5V
ON Low to High Transition
ON High to Low Transition
During Slow Fault Condition
During Normal and Reset Conditions
Latched Off Threshold, FILTER Low to High
TIMER On
TIMER Off, V
FAULT
= Low
V
TIMER
= 1.5V
TIMER Low to High
TIMER High to Low
FAULT High to Low
FAULT Low to High
q
q
q
q
q
q
q
1.209
1.234
0.5
3
1.259
V
mV
mV
1.250
1.172
– 2.5
7
1.10
– 23
0.9
1.172
1.172
– 2.5
1.314
1.234
80
–2
10
1.26
–70
– 20
1.6
2.5
1.234
0.3
1.234
50
–2
0.19
0.19
0.5
10
7
8
1.380
1.270
–1.3
13
1.42
–17
2.3
1.27
0.5
1.27
– 1.5
0.4
0.4
1
V
V
mV
µA
µA
V
mV
µA
µA
mA
V
V
V
mV
µA
V
V
µs
µs
q
q
q
q
q
q
q
q
V
TMR
V
FAULT
V
FAULT, HST
I
FAULT, UP
V
OLFAULT
V
OLRESETn
t
GATEFC
t
FAULTSC
t
OVPFTR
t
EXTFAULT
t
RESET
t
OFF
12
12
4.5
30
ms
µs
µs
µs
µs
1.5
3
15
8
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
All current into device pins is positive; all current out of device
pins is negative; all voltages are referenced to ground unless otherwise
specified.
Note 3:
An internal zener at the GATEn pin clamps the charge pump
voltage to a typical maximum operating voltage of 26V. External overdrive
of the GATEn pin beyond the internal zener voltage may damage the part.
The GATEn capacitance must be < 0.15µF at maximum V
CC
. If a lower
GATEn pin voltage is desired, use an external zener diode.
4230f
3
LTC4230
TYPICAL PERFOR A CE CHARACTERISTICS
Channel 1 Supply Current vs V
CC1
Supply Voltage
8
7
SUPPLY CURRENT (mA)
6
5
4
3
2
1
0
2
4
8
10 12 14
V
CC1
SUPPLY VOLTAGE (V)
6
16
18
–40°C
25°C
85°C
V
CC2
= 2.5V
V
CC3
= 1.8V
SUPPLY CURRENT (mA)
0.6
–40°C
0.5
0.4
CHANNEL 3
0.3
CHANNEL 2
0.2
0.1
0
25°C
85°C
UNDERVOLTAGE LOCKOUT THRESHOLD
VOLTAGE (V)
FBn Pin Input Current vs
Temperature
5
V
FBn
= 5V
6
SENSEn INPUT CURRENT (nA)
FB
n
PIN INPUT CURRENT (nA)
ON PIN INPUT CURRENT (nA)
4
3
2
1
0
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G04
ON Threshold vs Temperature
1.36
FAST COMPARATOR TRIP VOLTAGE (mV)
ON THRESHOLD VOLTAGE (V)
1.34
1.32
1.30
1.28
1.26
1.24
V
CC1
= 3.3V
V
CC2
= 2.5V
V
CC3
= 1.8V
ON PIN HIGH
151.5
151.0
150.5
150.0
149.5
149.0
148.5
148.0
–40°C
25°C
85°C
SLOW COMPARATOR TRIP VOLTAGE (mV)
ON PIN LOW
1.22
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G07
4
U W
4230 G01
Channels 2 and 3 Supply Current
vs Supply Voltage
2.5
UVLO Threshold Voltage vs
Temperature
2.2
V
CC1
HIGH
1.9
V
CC1
LOW
V
CC2
HIGH
1.6
V
CC2
LOW
V
CC3
HIGH
1.3
V
CC3
LOW
2
4
6
8
10 12 14
SUPPLY VOLTAGE (V)
16
18
1.0
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G03
4230 G02
ON Pin Input Current vs
Temperature
100
V
ON
= 5V
5
4
3
2
1
0
–75 –50 –25
90
80
70
60
50
40
30
20
10
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G05
SENSEn Input Current vs
Temperature
V
SENSEn
= 5V
0
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G06
Fast Comparator Threshold vs
V
CC1
Supply Voltage
152.0
52.0
Slow Comparator Threshold vs
V
CC1
Supply Voltage
–40°C
51.5
51.0
50.5
50.0
49.5
49.0
25°C
85°C
0
2
4
6
8 10 12 14
V
CC1
SUPPLY VOLTAGE (V)
16
18
0
2
4
6
8 10 12 14
V
CC1
SUPPLY VOLTAGE (V)
16
18
4230 G08
4230 G09
4230f
LTC4230
TYPICAL PERFOR A CE CHARACTERISTICS
Normal GATEn Pull-Down Current
vs V
CC1
Supply Voltage
280
FAST PULL-DOWN CURRENT (mA)
GATE PULL-DOWN CURRENT (µA)
260
240
220
200
180
160
140
120
2
4
8
10 12 14
V
CC1
SUPPLY VOLTAGE (V)
6
16
18
V
CC2
= 2.5V
V
CC3
= 1.8V
V
GATEn
= 2.5V
85°C
–40°C
25°C
20
I
GATE
CURRENT (µA)
V
GATEn
– V
CCn
vs V
CC1
Supply
Voltage
16
14
∆V
GATE
VOLTAGE (V)
12
V
GATE1
= V
GATE2
10
8
6
4
2
0
2
4
8
10 12 14
V
CC1
SUPPLY VOLTAGE (V)
6
16
18
V
CC2
= V
CC1
V
CC3
= V
CC1
– 1V
V
GATE3
V
GATE
– V
CC1
VOLTAGE (V)
GATE OVERVOLTAGE LOCKOUT THRESHOLD (V)
GATEn Overvoltage Lockout
Threshold vs V
CC1
Supply Voltage
GATE OVERVOLTAGE LOCKOUT THRESHOLD (V)
0.5
V
FB
THRESHOLD VOLTAGE (V)
FB THRESHOLD VOLTAGE (V)
V
CC2
= 2.5V
V
CC3
= 1.8V
0.4
0.3
0.2
0.1
0
0
2
4
6
8 10 12 14
V
CC1
SUPPLY VOLTAGE (V)
U W
4230 G10
4230 G13
Fast GATEn Pull-Down Current vs
V
CC1
Supply Voltage
12
11
–40°C
10
9
8
7
6
GATEn Output Source Current
(Pull-Up) vs V
CC1
Supply Voltage
85°C
18
25°C
16
25°C
85°C
V
CC2
= 2.5V
V
CC3
= 1.8V
V
GATEn
= 5V
0
2
4
6
8 10 12 14
V
CC1
SUPPLY VOLTAGE (V)
16
18
–40°C
14
12
10
0
2
4
6
8 10 12 14
V
CC1
SUPPLY VOLTAGE (V)
16
18
4230 G11
4230 G12
V
GATE1
– V
CC1
vs Temperature
16
14
12
10
8
V
CC1
= 3.3V
6
V
CC1
= 2.7V
4
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G14
GATEn Overvoltage Lockout
Threshold vs Temperature
0.5
V
CC1
= 3.3V
V
CC2
= 2.5V
V
CC3
= 1.8V
V
CC1
= 5V
V
CC1
= 12V
V
CC1
= 15V
0.4
0.3
0.2
0.1
0
–75 –50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G15
V
FBn
Threshold Voltage vs
Temperature
1.239
1.238
1.237
1.236
1.235
1.234
1.233
1.232
–75 –50 –25
1.233
0 25 50 75 100 125 150
TEMPERATURE (°C)
4230 G17
V
FBn
Threshold Voltage vs V
CC1
Supply Voltage
1.238
V
CC1
= 3.3V
V
CC2
= 2.5V
V
CC3
= 1.8V
V
FBn
HIGH
1.237
FB HIGH
1.236
1.235
FB LOW
V
FBn
LOW
1.234
16
18
0
2
4
6
8 10 12 14
V
CC1
SUPPLY VOLTAGE (V)
16
18
4230 G16
4230 G18
4230f
5