LTC4214-1/LTC4214-2
Negative Low Voltage
Hot Swap Controllers
FEATURES
s
s
s
DESCRIPTIO
s
s
s
s
s
s
s
Allows Safe Board Insertion and Removal from a
Live Backplane
Controls Supplies from 0V to –16V
Adjustable Analog Current Limit With Circuit
Breaker Timer
Fast Response Time Limits Peak Fault Current
Adjustable Soft-Start Current Limit
Adjustable Timer with Drain Voltage Accelerated
Response
Adjustable Undervoltage/Overvoltage Protection
LTC4214-1: Latch Off After Fault
LTC4214-2: Automatic Retry After Fault
Available in the 10-Pin MSOP Package
The LTC
®
4214 negative voltage Hot Swap
TM
controller
allows a board to be safely inserted and removed from a
live backplane. Output current is controlled by three stages
of current limiting: a timed circuit breaker, active current
limiting and a fast feedforward path that limits peak
current under worst-case catastrophic fault conditions.
Adjustable undervoltage and overvoltage detectors dis-
connect the load whenever the input supply exceeds the
desired operating range. The LTC4214 controls negative
supplies ranging from near zero to –16V. A multifunction
timer delays initial start-up and controls the circuit breaker’s
response time. This response time is accelerated by
sensing excessive MOSFET drain voltage, keeping the
MOSFET within its safe operating area (SOA). An adjust-
able soft-start circuit controls MOSFET inrush current at
start-up. A power good status output can enable a power
module at start-up or disable it if the circuit breaker trips.
The LTC4214-1 latches off after a circuit breaker fault times
out. The LTC4214-2 provides automatic retry after a fault.
The LTC4214 is available in the 10-pin MSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
s
s
s
s
Hot Board Insertion
Electronic Circuit Breaker
Negative Power Supply Control
Central Office Switching
High Availability Servers
Disk Arrays
Optical Networking/Switching
ECL
TYPICAL APPLICATIO
3.3V
– 5.2V/5A ECL Supply Hot Swap Controller
EN
2k
GND
10Ω
SMAJ7A
100nF
GND
(SHORT PIN)
34k
1%
32.4k
1%
5.6nF
1nF
PUSH
RESET
1
V
IN
LTC4214-1
2
PWRGD
9, 8
7
UV/OV DRAIN
10
6
TIMER
GATE
3
4
SS
SENSE
V
EE
3.3nF
5
10nF
4214 TA01
BSS138
GND
470Ω
C
LOAD
100µF
+
–5.2V
ECL
0.1µF
75k
IRF7413
22Ω
SENSE
20mV/DIV
V
OUT
5V/DIV
10Ω
0.01Ω
–5.2V
U
Start-Up Behavior
GATE
5V/DIV
PWRGD
5V/DIV
4214 TA02
U
U
421412f
1
LTC4214-1/LTC4214-2
ABSOLUTE
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
V
IN
PWRGD
SS
SENSE
V
EE
1
2
3
4
5
10
9
8
7
6
TIMER
UV
OV
DRAIN
GATE
All Voltages Referred to V
EE
(Note 1)
V
IN
............................................................ – 0.3V to 17V
Input/Output Pins
(Except SENSE and DRAIN) Voltage ..........– 0.3V to 17V
SENSE Pin Voltage ................................... – 0.6V to 17V
Current Out of SENSE Pin (20µs Pulse) ........... – 200mA
DRAIN Pin Minimum Voltage .............................. – 0.3V
Current into DRAIN Pin (100µs Pulse) ................... 5mA
Maximum Junction Temperature .......................... 125°C
Operating Temperature Range
LTC4214-1C/LTC4214-2C ....................... 0°C to 70°C
LTC4214-1I/LTC4214-2I ................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
LTC4214-1CMS
LTC4214-2CMS
LTC4214-1IMS
LTC4214-2IMS
MS PART MARKING
LTABH
LTABK
LTABJ
LTABL
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 160°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, UV = OV = 2.5V unless otherwise noted. (Note 2)
SYMBOL
V
IN
I
IN
V
LKO
V
LKH
V
CB
V
ACL
V
FCL
V
SS
R
SS
I
SS
V
OS
PARAMETER
Supply Voltage
V
IN
Supply Current
V
IN
Undervoltage Lockout
V
IN
Undervoltage Lockout Hysteresis
Circuit Breaker Current Limit Voltage
Analog Current Limit Voltage
Fast Current Limit Voltage
SS Voltage
SS Output Impedance
SS Pin Current
Analog Current Limit Offset Voltage
UV = OV = 2.5V, V
SENSE
= V
EE
, V
SS
= 0V (Sourcing)
UV = OV = 0V, V
SENSE
= V
EE
, V
SS
= 1V (Sinking)
V
CB
= (V
SENSE
– V
EE
)
V
ACL
= (V
SENSE
– V
EE
), SS = Open
V
FCL
= (V
SENSE
– V
EE
)
After End of SS Timing Cycle
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
q
MIN
6
q
q
TYP
0.8
5.1
0.3
MAX
16
2
5.6
56
80
300
UNITS
V
mA
V
V
mV
mV
mV
V
kΩ
µA
mA
mV
V/V
UV = OV = 2.5V
Coming Out of UVLO (Rising V
IN
)
44
60
150
50
70
200
1.6
73
–22
14
10
0.05
V
ACL
+V
OS
Ratio (V
ACL
+ V
OS
) to SS Voltage
V
SS
I
GATE
GATE Pin Output Current
V
SENSE
= V
EE
, V
GATE
= 0V (Sourcing)
V
SENSE
– V
EE
= 0.15V, V
GATE
= 3V (Sinking)
V
SENSE
– V
EE
= 0.3V, V
GATE
= 1V (Sinking)
V
GATE
– V
EE
V
GATEH
= V
IN
– V
GATE
for PWRGD Status
(Before Gate Ramp-Up)
UV Rising
OV Rising
q
q
q
q
q
–30
–50
17
190
11
2.8
0.5
–70
V
GATE
V
GATEH
V
GATEL
V
UVHI
V
UVHST
V
OVHI
V
OVHST
External MOSFET Gate Drive
Gate High Threshold
Gate Low Threshold
UV Pin Threshold
UV Pin Hysteresis
OV Pin Threshold
OV Pin Hysteresis
q
10
12
2.137
0.22
2.85
0.12
2.25
0.25
3
0.15
2.363
0.28
3.15
0.18
421412f
2
U
µA
mA
mA
V
V
V
V
V
V
V
W
U
U
W W
W
LTC4214-1/LTC4214-2
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, UV = OV = 2.5V unless otherwise noted. (Note 2)
SYMBOL
I
SENSE
I
INP
V
TMRH
V
TMRL
I
TMR
PARAMETER
SENSE Pin Input Current
UV, OV Pin Input Current
TIMER Pin Voltage High Threshold
TIMER Pin Voltage Low Threshold
TIMER Pin Current
Timer On (Initial Cycle/Latchoff/
Shutdown Cooling, Sourcing), V
TMR
= 2.2V
Timer Off (Initial Cycle, Sinking), V
TMR
= 2.2V
Timer On (Circuit Breaker, Sourcing,
I
DRN
= 0µA), V
TMR
= 2.2V
Timer On (Circuit Breaker, Sourcing,
I
DRN
= 20µA), V
TMR
= 2.2V
Timer Off (Circuit Breaker/
Shutdown Cooling, Sinking), V
TMR
= 2.2V
∆I
TMRACC
[(I
TMR
at I
DRN
= 20µA) – (I
TMR
at I
DRN
= 0µA)]
∆I
DRN
20µA
V
DRNL
I
DRNL
V
DRNCL
V
PGL
I
PGH
t
SS
t
PLLUG
t
PHLOG
DRAIN Pin Voltage Low Threshold
DRAIN Leakage Current
DRAIN Pin Clamp Voltage
PWRGD Output Low Voltage
PWRGD Pull-Up Current
SS Default Ramp Period
UV Low to Gate Low
OV High to Gate Low
Timer On (Circuit Breaker with I
DRN
= 20µA)
For PWRGD Status
V
DRAIN
= 2.5V
I
DRN
= 20µA
I
PG
= 1.6mA
I
PG
= 5mA
V
PWRGD
= 0V (Sourcing)
SS Pin Floating, V
SS
Ramps from 0.2V to 1.4V
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
V
SENSE
= 50mV
UV = OV = 2.5V
q
q
MIN
TYP
–15
±0.1
3
1.7
–5
28
–40
–200
5
8
MAX
–30
±1
UNITS
µA
µA
V
V
µA
mA
µA
µA
µA
µA/µA
1.109
3.5
1.232
±0.1
4.2
0.2
1.355
±1
5
0.4
1.1
–70
V
µA
V
V
V
µA
µs
µs
µs
–30
–50
130
0.4
0.4
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to V
EE
unless otherwise
specified.
TYPICAL PERFOR A CE CHARACTERISTICS
otherwise specified.
I
IN
vs Temperature
1200
1100
1000
I
IN
(mA)
V
IN
= 12V
900
V
LKO
(V)
0
2
4
6
8
10 12 14 16 18 20
V
IN
(V)
4214 G02
I
IN
(µA)
800
700
600
500
400
–55 –35 –15
5
25
45
65
85 105 125
4214 G01
TEMPERATURE (°C)
U W
All voltages are referenced to V
EE
Unless
Undervoltage Lockout
V
LKO
vs Temperature
I
IN
vs V
IN
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
T
A
= –40°C
T
A
= 25°C
T
A
= 85°C
T
A
= 125°C
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G03
421412f
3
LTC4214-1/LTC4214-2
TYPICAL PERFOR A CE CHARACTERISTICS
otherwise specified.
Undervoltage Lockout Hysteresis
V
LKH
vs Temperature
0.7
0.6
0.5
56
54
52
V
ACL
(mV)
V
CB
(mV)
V
LKH
(V)
0.4
0.3
0.2
0.1
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G04
Fast Current Limit Voltage
V
FCL
vs Temperature
300
275
250
V
IN
= 12V
1.80
1.75
1.70
V
FCL
(mV)
R
SS
(kΩ)
V
SS
(V)
225
200
175
150
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G07
I
SS
(Sinking) vs Temperature
25
V
IN
= 12V
UV = OV = V
SENSE
= V
EE
V
SS
= 1V
11.0
10.8
10.6
10.4
V
OS
(mV)
20
(V
ACL
+ V
OS
)/V
SS
(V/V)
I
SS
(mA)
15
10
5
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G10
4
U W
All voltages are referenced to V
EE
Unless
Analog Current Limit Voltage
V
ACL
vs Temperature
80
78
76
74
72
70
68
66
64
62
V
IN
= 12V
Circuit Breaker Current Limit
Voltage V
CB
vs Temperature
V
IN
= 12V
50
48
46
44
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G05
60
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G06
V
SS
vs Temperature
V
IN
= 12V
85
83
81
79
77
75
73
71
69
R
SS
vs Temperature
V
IN
= 12V
1.65
1.60
1.55
1.50
1.45
1.40
–55 –35 –15
67
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G08
65
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G09
V
OS
vs Temperature
V
IN
= 12V
0.060
0.058
0.056
0.054
0.052
0.050
0.048
0.046
0.044
0.042
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G11
(V
ACL
+ V
OS
)/V
SS
vs Temperature
V
IN
= 12V
10.2
10.0
9.8
9.6
9.4
9.2
9.0
–55 –35 –15
0.040
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G12
421412f
LTC4214-1/LTC4214-2
TYPICAL PERFOR A CE CHARACTERISTICS
otherwise specified.
I
GATE
(Sourcing) vs Temperature
60
58
56
54
I
GATE
(µA)
52
50
48
46
44
42
40
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G13
V
IN
= 12V
UV/OV = 2.5V
TIMER = 0V
V
SENSE
= V
EE
V
GATE
= 0V
I
GATE
(mA)
15
10
5
0
–55 –35 –15
I
GATE
(mA)
V
GATE
vs Temperature
12.0
11.8
11.6
11.4
V
IN
= 12V
UV/OV = 2.5V
TIMER = 0V
V
SENSE
= V
EE
3.6
3.4
3.2
V
GATE
(V)
11.2
11.0
10.8
10.6
10.4
10.2
10.0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G16
V
GATEH
(V)
V
GATEL
(V)
V
UVHI
vs Temperature
2.40
2.35
2.30
V
UVHST
(V)
V
IN
= 12V
V
UVHI
(V)
2.25
2.20
2.15
2.10
–55 –35 –15
0.25
0.24
0.23
0.22
–55 –35 –15
V
OVHI
(V)
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G19
U W
All voltages are referenced to V
EE
Unless
I
GATE
(FCL, Sinking)
vs Temperature
400
350
300
250
200
150
100
50
V
IN
= 12V
UV/OV = 2.5V
TIMER = 0V
V
SENSE
– V
EE
= 0.3V
V
GATE
= 1V
I
GATE
(ACL, Sinking)
vs Temperature
30
25
20
V
IN
= 12V
UV/OV = 2.5V
TIMER = 0V
V
SENSE
– V
EE
= 0.15V
V
GATE
= 3V
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G14
0
–55 –35 –15
5
25
45
65
85 105 125
4214 G15
TEMPERATURE (°C)
V
GATEH
vs Temperature
V
IN
= 12V
UV/OV = 2.5V
V
GATEH
= V
IN
– V
GATE
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
5
25
45
65
85 105 125
4214 G17
V
GATEL
vs Temperature
V
IN
= 12V
UV/OV = 2.5V
TIMER = 0V
GATE THRESHOLD
BEFORE RAMP-UP
3.0
2.8
2.6
2.4
2.2
2.0
–55 –35 –15
0
–55 –35 –15
5
25
45
65
85 105 125
4214 G18
TEMPERATURE (°C)
TEMPERATURE (°C)
V
UVHST
vs Temperature
0.28
0.27
0.26
V
IN
= 12V
3.15
3.10
3.05
3.00
2.95
2.90
V
OVHI
vs Temperature
V
IN
= 12V
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G20
2.85
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
4214 G21
421412f
5
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