LTC4221
Dual Hot Swap Controller/
Power Sequencer with Dual Speed,
Dual Level Fault Protection
FEATURES
■
■
■
■
■
■
■
■
■
■
■
DESCRIPTIO
Allows Safe Board Insertion and Removal from a
Live Backplane
Configurable Power Supply Sequencing
Soft-Start with Current Foldback Limits Inrush
Current
No External Gate Capacitor Required
Adjustable Dual Level Circuit Breaker Protection
Controls Supply Voltages from 1V to 13.5V
Independent N-Channel MOSFET High Side Drivers
FB Pin Monitors V
OUT
for Overvoltage Protection
Latch Off or Automatic Retry on Current Fault
FAULT and PWRGD Outputs
Narrow 16-Pin SSOP Package
The LTC
®
4221 is a 2-channel Hot Swap
TM
controller that
allows a board to be safely inserted and removed from a
live backplane. Using two independent high side gate
drivers to control two external N-channel pass transistors,
the output voltages can be ramped up with current foldback
to limit the inrush current during the start-up period. No
external compensation capacitors are required at the
GATE pins. The two channels can be configured to ramp up
and down separately or simultaneously for supply volt-
ages ranging from 2.7V to 13.5V and 1V to 13.5V for
channels 1 and 2 respectively.
Each channel has two current limit comparators that
provide dual level and dual speed overcurrent circuit
breaker protection after the start-up period. If any current
sense voltage exceeds 100mV for 1μs or 25mV for the
timeout delay (set by the C
FILTER
at the FILTER pin), then
the FAULT latch is set and both GATE pins are pulled low.
The FB pins monitor the respective channel output volt-
ages and provide the inputs for the PWRGD comparators
as well as overvoltage protection.
APPLICATIO S
■
■
■
■
Electronic Circuit Breaker
Power Supply Sequencing
Live Board Insertion and Removal
Industrial High Side Switch/Circuit Breaker
, 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
(FEMALE)
(MALE)
LONG
2-Channel Hot Swap Controller
V
CC1
3.3V
V
CC2
2.5V
0.004Ω
10Ω
100nF
*
100nF
10Ω
IRF7413
0.004Ω
IRF7413
LONG
*
SHORT
21k
10k
V
CC1
ON1
SENSE1 GATE1 V
CC2
SENSE2 GATE2
14.3k
FB2
5.11k
10k
10k
SHORT
13.3k
ON2
10k
LTC4221
FAULT
GND
TIMER
470nF
FAULT
GND
SHORT
LONG
*SMAJ10 (OPTIONAL)
FILTER
1nF
U
V
OUT1
3.3V/5A
V
OUT2
2.5V/5A
PWRGD2
PWRGD1
20k
U
U
PWRGD2
PWRGD1
FB1
5.11k
4221 TA01
4221fa
1
LTC4221
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
PI CO FIGURATIO
TOP VIEW
ON1
V
CC1
SENSE1
GATE1
FB1
PWRGD1
FAULT
FILTER
1
2
3
4
5
6
7
8
Supply Voltage (V
CCn
) ............................................ 17V
SENSEn Pins ............................ – 0.3V to (V
CCn
+ 0.3V)
FB, ON Pins .............................. – 0.3V to (V
CC1
+ 0.3V)
TIMER Pin .................................................. – 0.3V to 2V
GATE Pins (Note 3) ................................... – 0.3V to 21V
PWRGD, FAULT, FILTER Pins ................... – 0.3V to 17V
Operating Temperature Range
LTC4221C ............................................... 0°C to 70°C
LTC4221I ............................................ – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
GN PACKAGE
16-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 130°C/W
ORDER I FOR ATIO
LEAD FREE FINISH
LTC4221CGN#PBF
LTC4221IGN#PBF
LEAD BASED FINISH
LTC4221CGN
LTC4221IGN
TAPE AND REEL
LTC4221CGN#TRPBF
LTC4221IGN#TRPBF
TAPE AND REEL
LTC4221CGN#TR
LTC4221IGN#TR
PART MARKING
4221
4221I
PART MARKING
4221
4221I
PACKAGE DESCRIPTION
16-Lead Plastic SSOP
16-Lead Plastic SSOP
PACKAGE DESCRIPTION
16-Lead Plastic SSOP
16-Lead Plastic SSOP
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
SYMBOL
V
CC1
V
CC2
I
CC1
I
CC2
V
CC1(UVL)
ΔV
CC1(HYST)
V
CC2(UVL)
ΔV
CC2(HYST)
I
SENSE1(IN)
I
SENSE2(IN)
V
SENSE(FC)
V
SENSE(SC)
V
SENSE(ACL)
PARAMETER
Supply Voltage Channel 1
Supply Voltage Channel 2
V
CC1
Supply Current
V
CC2
Supply Current
Undervoltage Lockout for Channel 1
Undervoltage Lockout Hysteresis
Undervoltage Lockout for Channel 2
Undervoltage Lockout Hysteresis
SENSE1 Pin Input Current
SENSE2 Pin Input Current
SENSEn Threshold Voltage
SENSEn Threshold Voltage
SENSEn Voltage at Active
Current Limit
The
●
indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC1
= 5V, V
CC2
= 3.3V, unless otherwise noted.
CONDITIONS
●
MIN
2.7
1
●
●
●
●
●
●
●
●
●
V
CC2
≤
V
CC1
ON1, ON2 = 2V
ON1, ON2 = 2V
V
CC1
Rising
V
CC2
Rising
0V
≤
V
SENSE1
≤
V
CC1
V
SENSE2
= V
CC2
V
SENSE2
= 0V
Channeln Fast Comparator Threshold
Channeln Slow Comparator Threshold
V
FBn
= 0
V
FBn
= 0.65V
2.1
0.65
85
22.5
20.5
4
17.5
2
U
16 ON2
15 V
CC2
14 SENSE2
13 GATE2
12 FB2
11 PWRGD2
10 GND
9
TIMER
U
U
U
U
W W
W
W
U
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
TYP
MAX
13.5
13.5
UNITS
V
V
mA
mA
V
mV
V
mV
μA
μA
μA
mV
mV
mV
mV
mV
4221fa
2.2
0.05
2.5
110
0.8
25
±0.03
±0.2
1000
100
25
25
9
25
3
0.15
2.675
0.975
±5
±5
115
27.5
29.5
16
32.5
LTC4221
ELECTRICAL CHARACTERISTICS
SYMBOL
I
GATE(UP)
I
GATE(DN)
I
GATE(FSTDN)
ΔV
GATE
PARAMETER
GATEn Output Current
GATEn Output Current
GATEn Output Current
External N-Channel Gate Drive
The
●
indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC1
= 5V, V
CC2
= 3.3V, unless otherwise noted.
CONDITIONS
V
ON1
= V
ON2
= 2V, V
GATEn
= 0V
V
ON1
= V
ON2
= 0.6V, V
GATEn
= 3.3V
UVLO with V
GATEn
= 3.3V or FAULT
Latched with V
GATEn
= 3.3V
V
GATEn
– V
CC1
for V
CC1
= 2.7V, V
CC2
= 1V
V
GATEn
– V
CC1
for V
CC1
= 3.3V, V
CC2
= 2.5V
V
GATEn
– V
CC1
for V
CC1
= 5V, V
CC2
= 3.3V
V
GATEn
– V
CC1
for V
CC1
= 12V, V
CC2
= 12V
0V
≤
V
ONn
≤
V
CC1
V
ON1
Falling
High to Low, GATEn Turns Off by 100μA
Pull-Down
0V
≤
V
FBn
≤
V
CCn
FBn Falling
2.7V
≤
V
CC1
≤
13.5V
FBn Rising
During Current Fault Condition
During Normal Cycle
Latched Off Threshold, FILTER Rising
Initial Timing Cycle
Start-Up Cycle
V
TIMER
= 1.5V, End of Initial Timing Cycle
TIMER Rising
TIMER Falling
FAULT Falling
I
FAULT
= 1.6mA, V
CC1
= 5V
V
PWRGDn
= V
CC1
, V
FBn
= 0.7V, Normal Cycle
I
PWRGDn
= 1.6mA, V
CC1
= 5V, V
FBn
= 0V,
Normal Cycle
V
SENSEn
= V
CCn
to (V
CCn
– 200mV) Step
V
SENSEn
= V
CCn
to (V
CCn
– 50mV) Step.
FILTER Open
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
MIN
–7
75
TYP
–9.5
100
16
MAX
–12
125
UNITS
μA
μA
mA
4.5
5
8
7
0.4
±0.01
0.375
0.796
0.4
25
0.821
30
13
16
16
18
0.5
±1
0.425
0.846
V
V
V
V
V
μA
V
mV
V
mV
V
GATE(OV)
I
ON(IN)
V
ON(RESET)
ΔV
ON(RESETHYST)
V
ON(OFF)
ΔV
ON(OFFHYST)
I
FB(IN)
V
FB(UV)
ΔV
FB(UVHYST)
ΔV
FB(LREG)
V
FB(OV)
I
FILTER(UP)
I
FILTER(DN)
V
FILTER(TH)
ΔV
FILTER(HYST)
I
TMR(UP1)
I
TMR(UP2)
I
TMR(FSTDN)
V
TMR(H)
V
TMR(L)
I
FAULT(UP)
V
FAULT(TH)
ΔV
FAULT(HYST)
V
FAULT(OL)
I
PWRGD(LK)
V
PWRGD(OL)
t
P(FC-GATE)
t
P(SC-FAULT)
GATEn Overvoltage Lockout Threshold
ONn Pin Input Current
ON1 Reset Threshold
ON1 Reset Threshold Hysteresis
ONn Off Threshold
ONn Off Threshold Hysteresis
FBn Input Current
FBn Undervoltage Threshold
FBn Undervoltage Threshold Hysteresis
FBn Threshold Line Regulation
FBn Overvoltage Threshold
FILTER Pull-Up Current
FILTER Pull-Down Current
FILTER Threshold
FILTER Threshold Hysteresis
TIMER Pull-Up Current 1
TIMER Pull-Up Current 2
TIMER Pull-Down Current
TIMER High Threshold
TIMER Low Threshold
FAULT Pull-Up Current
FAULT Threshold
FAULT Hysteresis
FAULT Output Low Voltage
PWRGDn Leakage Current
PWRGDn Output Low Voltage
Fast Comparator Trip to GATEn
Discharging
Slow Comparator Trip to FILTER
High and FAULT Latched
●
●
±0.01
0.605
0.617
3
2
0.805
–80
1.15
1.18
–1.2
–15
1.172
0.1
–2.5
0.791
0.822
–105
1.8
1.24
105
–1.9
–20
9
1.234
0.4
–3.8
0.816
35
0.14
±0.01
0.14
1
15
±1
0.629
μA
V
mV
mV
0.838
–132
2.45
1.30
–2.6
–25
1.27
0.5
–5
0.841
0.4
±10
0.4
1.5
35
V
μA
μA
V
mV
μA
μA
mA
V
V
μA
V
mV
V
μA
V
μs
μs
4221fa
3
LTC4221
ELECTRICAL CHARACTERISTICS
SYMBOL
t
P(FAULT-GATE)
t
P(OV-GATE)
t
P(FILTER-GATE)
t
RESET
t
P(ON-GATE)
PARAMETER
FAULT Low to GATEn Discharging
FBn OV Comparator Trip to GATEn
Discharging
Filter Comparator Trip to GATEn
Discharging
Circuit Breaker Reset Delay Time
Turn Off Propagation Delay
The
●
indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC1
= 5V, V
CC2
= 3.3V, unless otherwise noted.
CONDITIONS
V
FAULT
= 3.3V to 0V
V
FBn
= 0V to 1V
V
FILTER
= 0V to 1.5V
V
ON1
< 0.4V to FAULT High
V
ONn
≤
0.821V to GATEn Discharging
●
●
●
●
●
MIN
TYP
15
18
15
15
15
MAX
35
35
35
30
35
UNITS
μs
μs
μs
μs
μs
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2:
All current into device pins are positive. All voltages are referenced
to ground unless otherwise specified.
Note 3:
An internal zener on each GATE pin clamps the charge pump
voltage to a typical maximum operating voltage of 26V. External overdrive
of either GATE pin beyond its internal zener voltage may damage the
device.
TYPICAL PERFOR A CE CHARACTERISTICS
I
CC1
vs Temperature
6
5
4
V
CC2
= 1V
V
CC1
= 13.5V
I
CC1
(mA)
I
CC2
(mA)
0.125
0.100
0.075
0.050
0.025
0
– 50 – 25
0
V
CC1(UVL)
(V)
V
CC1
= 12V
3
V
CC1
= 5V
2
V
CC1
= 2.7V
1
0
–50 –25
50
25
75
0
TEMPERATURE (°C)
V
CC2(UVL)
vs Temperature
0.815
0.810
0.805
RISING
TIMER = 0.3V
|I
SENSE2(IN)
| (μA)
V
CC2(UVL)
(V)
10
1
0.1
0.01
V
SENSE(FC)
(mV)
0.800
0.795
0.790
0.785
0.780
0.775
0.770
–50
–25
FALLING
0
25
50
75
TEMPERATURE (°C)
4
U W
100
100
I
CC2
vs Temperature
0.200
0.175
0.150
V
CC2
= 12V
V
CC1
= 13.5V
V
CC2
= 13.5V
2.52
2.50
2.48
2.46
2.44
2.42
2.40
2.38
50
75
25
TEMPERATURE (°C)
100
125
V
CC1(UVL)
vs Temperature
TIMER = 0.3V
RISING
V
CC2
= 5V
V
CC2
= 3.3V
V
CC2
= 1V
FALLING
125
2.36
– 50 – 25
0
50
75
25
TEMPERATURE (°C)
100
125
4221 G01
4221 G02
4221 G03
|I
SENSE2(IN)
| vs V
SENSE2
10000
1000
100
101.5
101.0
102.0
V
SENSE(FC)
vs V
CC1
V
CC2
= V
CC1
T
A
= 25°C
100.5
0.001
0.0001
125
V
CC1
= 2.7V, V
CC2
= 1V
V
CC1
= 5V, V
CC2
= 3.3V
V
CC1
= 13.5V, V
CC2
= 13.5V
0
2
4
6
8
10
12
4221 G05
100.0
99.5
0
2
4
6
8
V
CC1
(V)
4221 G06
10
12
14
16
V
SENSE2
(V)
4221 G04
4221fa
LTC4221
TYPICAL PERFOR A CE CHARACTERISTICS
V
SENSE(FC)
vs Temperature
102.0
101.5
V
SENSE(SC)
(mV)
V
SENSE(FC)
(mV)
V
CC1
= 5V
V
CC2
= 3.3V
V
SENSE(SC)
(mV)
101.0
100.5
100.0
99.5
99.0
–50 –25
50
25
75
0
TEMPERATURE (°C)
V
SENSE(ACL)
vs V
FB
30
V
CC1
= 5V
V
CC2
= 3.3V
25 T
A
= 25°C
V
SENSE(ACL)
(mV)
I
GATE(DN)
(μA)
I
GATE(UP)
(μA)
20
15
10
5
0
0
0.1
0.2
0.3 0.4
V
FB
(V)
0.5
0.6
0.7
I
GATE(FSTDN)
vs Temperature
60
50
I
GATE(FSTDN)
(mA)
V
CC2
= 1V
V
GATE
= 3.3V
V
CC1
= 2.7V
V
CC1
= 5V
V
CC1
= 13.5V
40
ΔV
GATE1
(V)
V
GATEn
(V)
30
20
10
0
–50 –25
50
25
75
0
TEMPERATURE (°C)
U W
100
100
V
SENSE(SC)
vs V
CC1
25.6
25.4
25.2
25.0
24.8
24.6
24.4
24.2
125
0
2
4
6
8
V
CC1
(V)
4221 G07
4221 G08
V
SENSE(SC)
vs Temperature
V
CC2
= V
CC1
T
A
= 25°C
26.0
V
CC1
= 5V
25.8 V
CC2
= 3.3V
25.6
25.4
25.2
25.0
24.8
24.6
10
12
14
16
24.4
– 50 – 25
0
50
75
25
TEMPERATURE (°C)
100
125
4221 G09
I
GATE(UP)
vs Temperature
–6
–7
–8
–9
–10
–11
V
CC1
= 2.7V
V
CC1
= 5V
V
CC1
= 13.5V
50
25
75
0
TEMPERATURE (°C)
100
125
V
CC2
= 1V
V
GATE
= 0V
104
103
102
101
100
99
98
I
GATE(DN)
vs Temperature
V
CC2
= 1V
V
GATE
= 3.3V
–12
–50 –25
97
–50 –25
V
CC1
= 2.7V
V
CC1
= 5V
V
CC1
= 13.5V
50
25
75
0
TEMPERATURE (°C)
100
125
4221 G10
4221 G11
4221 G12
ΔV
GATEn
(V
GATEn
– V
CC1
) vs V
CC1
15
14
13
12
11
10
9
8
7
V
CC2
= V
CC1
– 1.5V
T
A
= 25°C
ΔV
GATE1
ΔV
GATE2
ΔV
GATE1
(V
GATE1
– V
CC1
)
vs Temperature
18
16
14
12
10
8
6
4
–50 –25
V
CC1
= 2.7V, V
CC2
= 1V
V
CC1
= 5V, V
CC2
= 3.3V
V
CC1
= 13.5V, V
CC2
= 13.5V
125
6
0
2
4
6
8
V
CC1
(V)
10
12
14
50
25
75
0
TEMPERATURE (°C)
100
125
4221 G13
4221 G14
4221 G15
4221fa
5
京公网安备 11010802033920号
EEWORLD
