LTC1153
Auto-Reset
Electronic Circuit Breaker
FEATURES
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Programmable Trip Delay: 15µs to >100ms
Programmable Trip Current: 1mA to >20A
Programmbale Auto-Reset Time: 1ms to >10 sec.
4.5V to 18V Supply Range
Drives Low R
DS(ON)
N-Channel MOSFETs
Status Output Indicates Fault Condition
Thermal Trip with PTC Thermistor
8µA I
Q
in Standby Mode
No External Charge Pump Capacitors
Available in 8-Pin SOIC
The LTC1153 electronic circuit breaker drives a low cost
N-channel MOSFET to interrupt power to a sensitive
electronic load in the event of an over-current condition.
The breaker remains tripped for a period of time set by an
external timing capacitor and then is automatically reset.
This cycle continues until the over-current condition is
removed, protecting both the sensitive load and the
MOSFET switch.
The trip current, trip delay time and auto-reset period are
programmable over a wide range to accommodate a
variety of load impedances. An active high shutdown input
is also provided and interfaces directly to a PTC thermistor
for thermal circuit breaking. An open-drain output is
provided to report breaker status to the
µP.
The LTC1153 is available in both 8-pin DIP and 8-pin SOIC
packages.
APPLICATI
s
s
s
s
s
s
S
Power Bus Circuit Breaker
SCSI Termination Power Protection
Regulator Over-Current Protection
Battery Short-Circuit Protection
DC Motor Stall Protection
Sensitive System Power Interrupt
TYPICAL APPLICATI
5V/1A Electronic Circuit Breaker with 1ms Trip Delay,
200ms Auto-Reset Period and 70°C Thermal Shutdown
10
ON/OFF
C
T
0.22µF
Z5U
TO
µP
51k
GND
5V
**70°C
PTC
SENSITIVE
5V LOAD
SHUTDOWN
IN
C
T
LTC1153
STATUS
G
51k
IRLR024
VS
C
D
R
D
0.01µF 100k
DS
TRIP DELAY (ms)
*R
SEN
0.1Ω
1
0.1
ALL COMPONENTS SHOWN ARE SURFACE MOUNT.
* IMS026 INTERNATIONAL MANUFACTURING SERVICE, INC. (401) 683-9700
** RL2006-100-70-30-PT1 KEYSTONE CARBON COMPANY (814) 781-1591
LTC1153 • TA01
0.01
1
10
CIRCUIT BREAKER CURRENT (A)
100
U
Trip Delay Time
R
SEN
= 0.1Ω
R
D
= 100k
C
D
= 0.01µF
LTC1153 • TA02
UO
UO
1
LTC1153
ABSOLUTE
AXI U
RATI GS
Current (Any Pin).................................................. 50mA
Operating Temperature
LTC1153C .............................................. 0°C to 70°C
Storage Temperature Range ................. – 65°c to 150°C
Lead Temperature (Soldering, 10 sec.)................ 300°C
Supply Voltage ........................................................ 22V
Input Voltage ..................... (V
S
+ 0.3V) to (GND – 0.3V)
Timing Capacitor Voltage ... (VS + 0.3V) to (GND – 0.3V)
Gate Voltage ....................... (VS + 24V) to (GND – 0.3V)
Status Output Voltage .............................................. 15V
PACKAGE/ORDER I FOR ATIO
TOP VIEW
IN 1
TIMING CAP 2
STATUS 3
GND 4
8
7
6
5
V
S
DRAIN SENSE
GATE
SHUTDOWN
ORDER PART
NUMBER
LTC1153CN8
N8 PACKAGE
8-LEAD PLASTIC DIP
LTC1153 • PO01
T
JMAX
= 100°C,
θ
JA
= 130°C/W (N8)
ELECTRICAL CHARACTERISTICS
V
S
= 4.5V to 18V, T
A
= 25°C, C
T
= 0.1µF, V
SD
= 0V unless otherwise noted.
SYMBOL
V
S
I
Q
I
Q
I
Q
V
INH
V
INL
I
IN
C
IN
V
CT
I
CT
V
SDH
V
SDL
I
SD
V
SEN
I
SEN
PARAMETER
Supply Voltage
Quiescent Current OFF
Quiescent Current ON
Quiescent Current ON
Input High Voltage
Input Low Voltage
Input Current
Input Capacitance
Timing Capacitor Threshold Voltage
Timing Capacitor Current
Shutdown Input High Voltage
Shutdown Input Low Voltage
Shutdown Input Current
Drain Sense Threshold Voltage
q
CONDITIONS
q
V
S
= 5V, V
IN
= 0V
V
S
= 5V, V
IN
= 5V
V
S
=12V, V
IN
= 5V
q
q
0
V
< V
IN
< V
S
V
S
= 5V
V
S
= 12V
V
S
= 12V
0V < V
IN
< V
S
Drain Sense Input Current
0V < V
SEN
< V
S
2
U
U
W
W W
U
W
TOP VIEW
IN 1
TIMING CAP 2
STATUS 3
GND 4
8
7
6
5
V
S
DRAIN SENSE
GATE
SHUTDOWN
ORDER PART
NUMBER
LTC1153CS8
S8 PACKAGE
8-LEAD PLASTIC SOIC
LTC1154 • PO02
S8 PART MARKING
1153
T
JMAX
= 100°C,
θ
JA
= 150°C/W
MIN
4.5
LTC1153C
TYP
8
85
180
MAX
18
20
120
400
0.8
±1
UNITS
V
µA
µA
µA
V
V
µA
pF
V
V
µA
V
V
µA
mV
mV
µA
2
q
5
2.1
2.0
3.0
q
q
q
2.5
2.6
4.2
2.9
3.2
6.0
0.8
±1
2
80
75
100
100
120
125
±0.1
q
LTC1153
ELECTRICAL CHARACTERISTICS
V
S
= 4.5V to 18V, T
A
= 25°C, C
T
= 0.1µF, V
SD
= 0V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
V
S
= 5V
V
S
= 6V
V
S
= 12V
I
STAT
= 400µA
V
STAT
= 12V
V
S
= 5V, C
GATE
= 1000pF
Time for V
GATE
> V
S
+ 2V
Time for V
GATE
> V
S
+ 5V
V
S
= 12V, C
GATE
= 1000pF
Time for V
GATE
> V
S
+ 5V
Time for V
GATE
> V
S
+ 10V
t
OFF
Turn-OFF Time
V
S
= 5V, C
GATE
= 1000pF
Time for V
GATE
< 1V
V
S
= 12V, C
GATE
= 1000pF
Time for V
GATE
< 1V
t
TD
Minimum Trip Delay
V
S
= 5V, C
GATE
= 1000pF
Time for V
GATE
< 1V
V
S
= 12V, C
GATE
= 1000pF
Time for V
GATE
< 1V
t
SD
Shutdown Turn-OFF Time
V
S
= 5V, C
GATE
= 1000pF
Time for V
GATE
< 1V
V
S
= 12V, C
GATE
= 1000pF
Time for V
GATE
< 1V
The
q
denotes specifications which apply over the operating temperature range.
q
q
q
q
q
MIN
6.0
7.5
15.0
LTC1153C
TYP
7.0
8.3
18.0
0.05
MAX
9.0
15.0
25.0
0.4
1
UNITS
V
V
V
V
µA
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
V
GATE
– V
S
Gate Voltage Above Supply
V
STAT
I
STAT
t
ON
Status Output Low Voltage
Status Output Leakage Current
Turn-ON Time
30
100
20
50
10
10
5
5
110
450
80
160
36
28
25
23
17
13
300
1000
200
500
60
60
40
40
40
35
TYPICAL PERFOR A CE CHARACTERISTICS
Standby Supply Current
50
45
40
SUPPLY CURRENT (µA)
V
IN
= 0V
T
A
= 25°C
SUPPLY CURRENT (µA)
35
30
25
20
15
10
5
0
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC01
600
500
400
300
200
100
0
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC02
V
GATE
– V
S
(V)
U W
Supply Current ON
1000
900
800
700
T
A
= 25°C
24
22
20
18
16
14
12
10
8
6
4
MOSFET Switch Gate Voltage
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC03
3
LTC1153
TYPICAL PERFOR A CE CHARACTERISTICS
Input Threshold Voltage
2.4
2.2
INPUT THRESHOLD VOLTAGE (V)
DRAIN SENSE THRESHOLD VOLTAGE (mV)
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC04
120
110
100
90
80
70
60
50
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC05
RESET PERIOD (SEC)
V
ON
V
OFF
MOSFET Gate Turn-ON Time
1000
900
800
C
GATE
= 1000pF
50
45
40
TURN OFF TIME (µs)
TURN ON TIME (µs)
700
600
500
400
300
200
100
0
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC07
30
25
20
15
10
5
0
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC08
TRIP TIME (µs)
V
GS
= 5V
V
GS
= 2V
Standby Supply Current
50
45
40
V
IN
= 0V
800
SUPPLY CURRENT (µA)
INPUT THRESHOLD VOLTAGE (V)
SUPPLY CURRENT (µA)
35
30
25
20
15
10
5
0
–50 –25
V
S
= 18V
V
S
= 5V
50
25
0
75
TEMPERATURE (°C)
100
125
4
U W
LTC1153 • TPC10
Drain Sense Threshold Voltage
150
140
130
Auto-Reset Period
10
T
A
= 25°C
3.3µF
1
1µF
0.33µF
0.1
0.1µF
0.033µF
0.01
0
5
10
15
20
SUPPLY VOLTAGE (V)
LTC1153 • TPC06
MOSFET Gate Turn-OFF Time
50
C
GATE
= 1000pF
TIME FOR V
GATE
< 1V
Built-In Trip Delay
45
40
35
30
25
20
15
10
5
0
0
5
10
15
SUPPLY VOLTAGE (V)
20
LTC1153 • TPC09
C
GATE
= 1000pF
TIME FOR V
GATE
< 1V
V
SEN
= V
S
– 1V
NO EXTERNAL DELAY
35
Supply Current ON
1000
900
V
IN
= 5V
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.O
0.8
0.6
100
125
Input ON Threshold Voltage
700
600
500
400
300
200
100
V
S
= 5V
V
S
= 12V
V
S
= 5V
V
S
= 18V
0
–50 –25
50
25
0
75
TEMPERATURE (°C)
0.4
–50 –25
50
25
0
75
TEMPERATURE (°C)
100
125
LTC1153 • TPC11
LTC1153 • TPC12
LTC1153
TYPICAL PERFOR A CE CHARACTERISTICS
Shutdown Threshold Voltage
2.4
10
*SECONDS OF DELAY
PER
µF
C
T
SHUTDOWN THRESHOLD VOLTAGE (V)
2.2
2.0
1.8
1.6
1.4
1.2
1.O
0.8
0.6
0.4
–50 –25
50
25
0
75
TEMPERATURE (°C)
100
125
V
S
= 5V
V
S
= 18V
AUTO-RESET TIME (s/µF)
GATE DRIVE CURRENT (µA)
PI FU CTIO S
Input and Shutdown Pins
The LTC1153 input pin is active high and activates all of the
protection and charge pump circuitry when switched ON.
The shutdown pin is designed to break the circuit if a
secondary fault condition (over temperature, etc.) is de-
tected. The LTC1153 logic and shutdown inputs are high
impedance CMOS gates with ESD protection diodes to
ground and supply and therefore should not be forced
beyond the power supply rails. The shutdown pin should
be connected to ground when not in use.
Timing Capacitor Pin (Auto-Reset Timer)
The small capacitor charging current (4.2µA) produces
large delays with relatively small valued capacitors, but
care must be taken to ensure that this current is not
shunted to ground through a leaky capacitor or printed
circuit board trace. The timing capacitor voltage is sensed
by a high impedance CMOS comparator input with ESD
clamp diodes to ground and supply and therefore should
not be forced beyond the power supply rails. This pin can
be grounded if the auto-reset function is not used.
MOSFET Gate Drive Pin
The MOSFET gate drive pin is either driven to ground when
the switch is turned OFF or driven above the supply rail
when the switch is turned ON. This pin is a relatively high
impedance when driven above the rail (the equivalent of a
few hundred kΩ). Care should be taken to minimize any
loading of this pin by parasitic resistance to ground or
supply.
Supply Pin
The supply pin of the LTC1153 serves two vital purposes.
The first is obvious: it powers the input, gate drive, regu-
lation and protection circuitry. The second purpose is less
obvious: it provides a Kelvin connection to the top of the
drain sense resistor for the internal 100mV reference.
The LTC1153 is designed to be
continuously powered
so
that the gate of the MOSFET is actively driven at all times.
If it is necessary to remove power from the supply pin and
then re-apply it, the input pin (or enable pin) should be
cycled a few milliseconds
after
the power is re-applied to
reset the input latch and protection circuitry. Also, the
input and enable pins should be isolated with 10k resistors
to limit the current flowing through the ESD protection
diodes to the supply pin.
U W
LTC1153 • TPC13
Auto-Reset Time*
1000
MOSFET Gate Drive Current
T
A
= 25°C
100
V
S
= 18V
V
S
= 12V
10
V
S
= 12V
1
V
S
= 5V
V
S
= 18V
1
V
S
= 5V
0.1
–50
0.1
–25
0
50
75
25
TEMPERATURE (°C)
100
125
0
4
8
12
16
GATE VOLTAGE ABOVE SUPPLY (V)
20
LTC1153 • TPC14
LTC1153 • TPC15
U
U
U
The supply pin of the LTC1153 should never be forced
below ground as this may result in permanent damage to
the device.
A 300Ω resistor should be inserted in series
with the ground pin if negative supply voltage transients
are anticipated.
5
