LTC1155
Dual High Side
Micropower MOSFET Driver
FEATURES
DESCRIPTION
Fully Enhances N-Channel Power MOSFETs
n 8µA Standby Current
n 85µA ON Current
n Short-Circuit Protection
n Wide Power Supply Range: 4.5V to 18V
n Controlled Switching ON and OFF Times
n No External Charge Pump Components
n Replaces P-Channel High Side MOSFETs
n Compatible with Standard Logic Families
n Available in 8-Pin SO Package
The LTC®1155 dual high side gate driver allows using low
cost N-channel FETs for high side switching applications.
An internal charge pump boosts the gate above the positive rail, fully enhancing an N-channel MOSFET with no
external components. Micropower operation, with 8µA
standby current and 85µA operating current, allows use
in virtually all systems with maximum efficiency.
n
APPLICATIONS
Included on-chip is overcurrent sensing to provide automatic shutdown in case of short circuits. A time delay
can be added in series with the current sense to prevent
false triggering on high in-rush loads such as capacitors
and incandescent lamps.
n
n
n
n
n
n
The LTC1155 is available in both 8-pin PDIP and 8-pin
SO packages.
n
The LTC1155 operates off of a 4.5V to 18V supply input and
safely drives the gates of virtually all FETs. The LTC1155
is well suited for low voltage (battery-powered) applications, particularly where micropower “sleep” operation
is required.
Laptop Power Bus Switching
SCSI Termination Power Switching
Cellular Phone Power Management
P-Channel Switch Replacement
Relay and Solenoid Drivers
Low Frequency Half H-Bridge
Motor Speed and Torque Control
All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION
Laptop Computer Power Bus Switch with Short-Circuit Protection
VS = 4.5V TO 5.5V
*IRLR034
5A
MAX
TTL, CMOS INPUT
DS1
VS
DS2
G1
LTC1155
G2
IN1
GND
IN2
10µF
CDLY
0.1µF
RDLY
100k
Switch Voltage Drop
RSEN
0.02Ω
0.25
0.20
VOLTAGE DROP (V)
+
CDLY
0.1µF
RSEN
0.02Ω
RDLY
100k
*IRLR034
5A
MAX
TTL, CMOS INPUT
POWER BUS
0.15
0.10
0.05
µP
SYSTEM
DISK
DRIVE
DISPLAY
PRINTER,
ETC.
0.00
GND
0
1
2
OUTPUT CURRENT (A)
3
1155 TA02
*SURFACE MOUNT
1155 TA01
Rev. C
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1
LTC1155
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage...........................................................22V
Input Voltage.........................(VS +0.3V) to (GND – 0.3V)
Gate Voltage...........................(VS +24V) to (GND – 0.3V)
Current (Any Pin)....................................................50mA
Storage Temperature Range................... – 65°C to 150°C
Operating Temperature Range
LTC1155C................................................. 0°C to 70°C
LTC1155I............................................. – 40°C to 85°C
LTC1155M (OBSOLETE).................... – 55°C to 125°C
Lead Temperature Range (Soldering, 10 sec.)....... 300°C
PIN CONFIGURATION
TOP VIEW
DS1 1
8 DS2
G1 2
7 G2
GND 3
6 VS
TOP VIEW
5 IN2
IN1 4
J8 PACKAGE
8-LEAD CERDIP
TJMAX = 150°C, θJA = 100°C/W (J8)
OBSOLETE PACKAGE
TOP VIEW
DS1 1
8 DS2
DS1 1
8
DS2
G1 2
7 G2
G1 2
7
G2
GND 3
6 VS
GND 3
6
VS
IN1 4
5 IN2
IN1 4
5
IN2
N8 PACKAGE
8-LEAD PDIP
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 100°C, θJA = 130°C/W (N8)
TJMAX = 100°C, θJA = 150°C/W
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC1155CN8#PBF
LTC1155CN8#TRPBF
PART MARKING*
8-Lead PDIP
0°C to 70°C
LTC1155IN8#PBF
LTC1155IN8#TRPBF
8-Lead PDIP
–40°C to 85°C
OBSOLETE PACKAGE
LTC1155CJ8#PBF
LTC1155CJ8#TRPBF
8-Lead CERDIP
0°C to 70°C
LTC1155MJ8#PBF
LTC1155MJ8#TRPBF
8-Lead CERDIP
–55°C to 125°C
LTC1155CS8#PBF
LTC1155CS8#TRPBF
1155
8-Lead Plastic SO
0°C to 70°C
LTC1155IS8#PBF
LTC1155IS8#TRPBF
1155I
8-Lead Plastic SO
–40°C to 85°C
Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
Rev. C
2
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LTC1155
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = 4.5V to 18V, unless otherwise noted.
LTC1155M (OBSOLETE)
MIN
TYP
MAX
SYMBOL
PARAMETER
CONDITIONS
VS
Supply Voltage
IQ
Quiescent Current OFF
VIN = 0V, VS = 5V (Note 2)
Quiescent Current ON
VS = 5V, VIN = 5V (Note 3)
85
Quiescent Current ON
VS = 12V, VIN = 5V (Note 3)
180
l
4.5
18
8
LTC1155C/LTC1155I
MIN
TYP
MAX
4.5
UNITS
18
V
8
20
µA
120
85
120
µA
400
180
400
µA
20
VINH
Input High Voltage
l
VINL
Input Low Voltage
l
0.8
0.8
V
IIN
Input Current
l
±1.0
±1.0
µA
120
125
mV
mV
±0.1
µA
0V < VIN < VS
CIN
Input Capacitance
VSEN
Drain Sense Threshold Voltage
ISEN
Drain Sense Input Current
0V < VSEN < VS
VGATE-VS
Gate Voltage Above Supply
VS = 5V
VS = 6V
VS = 12V
tON
Turn ON Time
tSC
Turn OFF Time
Short-Circuit Turn OFF Time
2.0
5
l
tOFF
2.0
80
75
100
100
V
5
120
125
80
75
100
100
±0.1
pF
6.0
7.5
15
6.8
8.5
18
9.0
15
25
6.0
7.5
15
6.8
8.5
18
9.0
15
25
V
V
V
VS = 5V, CGATE = 1000pF
Time for VGATE > VS + 2V
Time for VGATE > VS + 5V
50
200
250
1100
750
2000
50
200
250
1100
750
2000
µs
µs
VS = 12V, CGATE = 1000pF
Time for VGATE > VS + 5V
Time for VGATE > VS + 10V
50
120
180
450
500
1200
50
120
180
450
500
1200
µs
µs
VS = 5V, CGATE = 1000pF
Time for VGATE < 1V
10
36
60
10
36
60
µs
VS = 12V, CGATE = 1000pF
Time for VGATE < 1V
10
26
60
10
26
60
µs
VS = 5V, CGATE = 1000pF
Time for VGATE < 1V
5
16
30
5
16
30
µs
VS = 12V, CGATE = 1000pF
Time for VGATE < 1V
5
16
30
5
16
30
µs
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
l
l
l
Note 2: Quiescent current OFF is for both channels in OFF condition.
Note 3: Quiescent current ON is per driver and is measured independently.
Rev. C
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3
LTC1155
TYPICAL PERFORMANCE CHARACTERISTICS
Standby Supply Current
Supply Current/Side (ON)
1000
VIN1 = VIN2 = 0V
TJ = 25°C
45
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
VIN1 OR VIN2 = 2V
TJ = 25°C
900
40
35
30
25
20
22
800
20
700
18
600
500
400
12
300
10
200
8
5
100
6
0
0
15
5
10
SUPPLY VOLTAGE (V)
0
20
0
15
5
10
SUPPLY VOLTAGE (V)
Input Threshold Voltage
VON
1.6
1.4
VOFF
1.2
1.0
0.8
0.6
0.4
15
5
10
SUPPLY VOLTAGE (V)
0
30
140
27
130
24
120
21
110
18
100
90
20
9
6
60
3
0
15
5
10
SUPPLY VOLTAGE (V)
0
20
CGATE = 1000pF
35
300
200
VGS = 2V
100
0
0
15
5
10
SUPPLY VOLTAGE (V)
20
TURN-OFF TIME (µs)
40
35
TURN OFF TIME (µs)
40
700
VGS = 5V
30
25
20
15
30
25
15
10
5
5
0
15
5
10
SUPPLY VOLTAGE (V)
1155 G07
20
1155 G08
VSEN = VS –1V
NO EXTERNAL DELAY
20
10
0
10
CGATE = 1000pF
TIME FOR VGATE < 1V
45
800
400
8
6
4
SUPPLY VOLTAGE (V)
Short-Circuit Turn OFF Delay Time
50
CGATE = 100pF
TIME FOR VGATE < 1V
45
600
2
1155 G06
Turn OFF Time
50
500
0
1155 G05
Turn ON Time
900
12
70
1155 G04
1000
15
80
50
20
Low Side Gate Voltage
150
VGATE (V)
DRAIN SENSE THRESHOLD VOLTAGE (V)
2.0
15
5
10
SUPPLY VOLTAGE (V)
0
1155 TPC03
Drain Sense Threshold Voltage
2.2
1.8
4
20
1155 G02
2.4
TURN-ON TIME (µs)
16
14
10
15
1155 G01
INPUT THRESHOLD VOLTAGE (V)
High Side Gate Voltage
24
V GATE – VS (V)
50
0
0
15
5
10
SUPPLY VOLTAGE (V)
20
1155 G09
Rev. C
4
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LTC1155
TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current Per Side (ON)
Input ON Threshold
2.4
45
900
2.2
40
800
2.0
35
30
25
20
VS = 18V
15
10
5
700
600
500
400
300
200
VS = 5V
0
–50 – 25
100
0
25
50
75
TEMPERATURE (°C)
100
125
INPUT THRESHOLD (V)
1000
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
Standby Supply Current
50
VS = 12V
1.6
1.4
VS = 5V
1.2
1.0
VS = 18V
0.8
VS = 5V
0
– 50 –25
1.8
0.6
0
25
50
75
TEMPERATURE (°C)
100
1155 G10
125
1155 G11
0.4
–50 – 25
0
25
50
75
TEMPERATURE (°C)
100
125
1155 G12
PIN FUNCTIONS
Input Pin
The LTC1155 logic input is a high impedance CMOS gate
and should be grounded when not in use. These input
pins have ESD protection diodes to ground and supply
and, therefore, should not be forced beyond the power
supply rails.
Gate Drive Pin
The 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 LTC1155 serves two vital purposes.
The first is obvious: it powers the input, gate drive, regulation and protection circuitry. The second purpose is less
obvious: it provides a Kelvin connection to the top of the
two drain sense resistors for the internal 100mV reference.
The supply pin should be connected directly to the power
supply source as close as possible to the top of the two
sense resistors.
The supply pin of the LTC1155 should not 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 voltages are anticipated.
Drain Sense Pin
As noted previously, the drain sense pin is compared
against the supply pin voltage. If the voltage at this pin is
more than 100mV below the supply pin, the input latch will
be reset and the MOSFET gate will be quickly discharged.
Cycle the input to reset the short-circuit latch and turn the
MOSFET back on.
This pin is also a high impedance CMOS gate with ESD
protection and, therefore, should not be forced beyond the
power supply rails. To defeat the over current protection,
short the drain sense to supply.
Some loads, such as large supply capacitors, lamps or
motors require high inrush currents. An RC time delay
must be added between the sense resistor and the drain
sense pin to ensure that the drain sense circuitry does not
false trigger during start-up. This time constant can be
set from a few microseconds to many seconds. However,
very long delays may put the MOSFET in risk of being
destroyed by a short-circuit condition (see Applications
Information section).
Rev. C
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5
LTC1155
BLOCK DIAGRAM
VS
LOW STANDBY
CURRENT
REGULATOR
100mV
REFERENCE
ANALOG
IN
DRAIN
SENSE
ANALOG SECTION
TTL-TO-CMOS
CONVERTER
COMP
10µs
DELAY
GATE CHARGE
AND DISCHARGE
CONTROL LOGIC
DIGITAL
VOLTAGE
REGULATORS
R
ONE
SHOT
S
GATE
INPUT
LATCH
GND
OSCILLATOR
AND CHARGE
PUMP
FAST/SLOW
GATE CHARGE
LOGIC
1155 BD
OPERATION
The LTC1155 contains two independent power MOSFET
gate drivers and protection circuits (refer to the Block
Diagram for details). Each half of the LTC1155 consists
of the following functional blocks:
TTL and CMOS Compatible Inputs
Each driver input has been designed to accommodate a
wide range of logic families. The input threshold is set at
1.3V with approximately 100mV of hysteresis.
A voltage regulator with low standby current provides
continuous bias for the TTL to CMOS converters. The TTL
to CMOS converter output enables the rest of the circuitry.
In this way the power consumption is kept to a minimum
in the standby mode.
Internal Voltage Regulation
The output of the TTL to CMOS converter drives two
regulated supplies which power the low voltage CMOS
logic and analog blocks. The regulator outputs are isolated
from each other so that the noise generated by the charge
pump logic is not coupled into the 100mV reference or
the analog comparator.
Gate Charge Pump
Gate drive for the power MOSFET is produced by an
adaptive charge pump circuit that generates a gate voltage substantially higher than the power supply voltage.
The charge pump capacitors are included on-chip and,
therefore, no external components are required to generate the gate drive.
Drain Current Sense
The LTC1155 is configured to sense the drain current of
the power MOSFET in high side applications. An internal
100mV reference is compared to the drop across a sense
resistor (typically 0.002Ω to 0.1Ω) in series with the drain
lead. If the drop across this resistor exceeds the internal
100mV threshold, the input latch is reset and the gate is
quickly discharged by a large N-channel transistor.
Controlled Gate Rise and Fall Times
When the input is switched ON and OFF, the gate is
charged by the internal charge pump and discharged in a
controlled manner. The charge and discharge rates have
been set to minimize RFI and EMI emissions in normal
operation. If a short circuit or current overload condition
is encountered, the gate is discharged very quickly (typically a few microseconds) by a large N-channel transistor.
Rev. C
6
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LTC1155
APPLICATIONS INFORMATION
Protecting the MOSFET
in the power supply can be substantial and attributed to
many sources including harness wiring, PCB traces, supply
capacitor ESR, transformer resistance or battery resistance.
The MOSFET is protected against destruction by removing
drive from the gate as soon as an overcurrent condition is
detected. Resistive and inductive loads can be protected
with no external time delay. Large capacitive or lamp loads,
however, require that the overcurrent shutdown function
be delayed long enough to start the load but short enough
to ensure the safety of the MOSFET.
For this example, we assume a worst-case scenario; i.e.,
that the power supply to the power MOSFET is “hard” and
provides a constant 5V regardless of the current. In this
case, the current is limited by the RDS(ON) of the MOSFET
and the drain sense resistance. Therefore:
Example Calculations
IPEAK = VSUPPLY/0.08Ω
Consider the circuit of Figure 1. A power MOSFET is driven
by one side of an LTC1155 to switch a high inrush current load. The drain sense resistor is selected to limit the
maximum DC current to 3.3A.
The drop across the drain sense resistor under these
conditions is much larger than 100mV and is equal to the
drain current times the sense resistance:
RSEN = VSEN/ITRIP
= 0.1/3.3A
= 0.03Ω
= 62.5A
VDROP = (IPEAK)(RSEN)
A time delay is introduced between RSEN and the drain
sense pin of the LTC1155 which provides sufficient delay
to start a high inrush load such as large supply capacitors.
In this example circuit, we have selected the IRLZ34 because
of its low RDS(ON)(0.05Ω with VGS = 5V). The FET drops
0.1V at 2A and, therefore, dissipates 200mW in normal
operation (no heat sinking required).
= 1.88V
By consulting the power MOSFET data sheet SOA graph,
we note that the IRLZ34 is capable of delivering 62.5A at a
drain-to-source voltage of 3.12V for approximately 10ms.
An RC time constant can now be calculated which satisfies
this requirement:
RC =
VS = 5.0V
CDLY
0.22µF
VS
IN1
DS1
RSEN
0.03Ω
RC =
RDLY
270k
⎡
⎤
V SEN
In ⎢ 1 −
⎥
⎢⎣ R SEN • I MAX ⎥⎦
– 0.01
⎡
⎤
0.10
In ⎢ 1 −
⎥
⎣ 0.030 • 62.5 ⎦
= – 0.01/– 0.054
LTC1155
GND
–t
G1
IRLZ34
LOAD
GND
1155 F01
Figure 1. Adding an RC Delay
If the output is shorted to ground, the current through
the FET rises rapidly and is limited by the RDS(ON) of the
FET, the drain sense resistor and the series resistance
between the power supply and the FET. Series resistance
= 182ms
This time constant should be viewed as a maximum
safe delay time and should be reduced if the competing
requirement of starting a high inrush current load is less
stringent; i.e., if the inrush time period is calculated at
20ms, the RC time constant should be set at roughly two
or three times this time period and not at the maximum
of 182ms. A 60ms time constant would be produced
with a 270k resistor and a 0.22µF capacitor (as shown in
Figure 1).
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Rev. C
7
LTC1155
APPLICATIONS INFORMATION
Graphical Approach to Selecting RDLY and CDLY
Figure 2 is a graph of normalized overcurrent shutdown
time versus normalized MOSFET current. This graph can
be used instead of the above equation to calculate the RC
time constant. The Y axis of the graph is normalized to
one RC time constant. The X axis is normalized to the set
current. (The set current is defined as the current required
to develop 100mV across the drain sense resistor).
to the sense pin and dramatically reducing the amount of
time the MOSFET is in an overload condition. The drain
sense resistor value is selected to limit the maximum DC
current to 4A. Above 28A, the delay time drops to 10µs.
VS = 5.0V
CDLY
0.22µF
VS
Note that the shutdown time is shorter for increasing
levels of MOSFET current. This ensures that the total
energy dissipated by the MOSFET is always within the
bounds established by the MOSFET manufacturer for
safe operation.
IN1
RDLY
270k
DS1
D1
1N4148
LTC1155
IRLZ34
G1
GND
LOAD
GND
10
OVERCURRENT SHUTDOWN TIME (1= RC)
RSEN
0.025Ω
1155 F03
Figure 3. Using a Speed-Up Diode
1
Switched Supply Applications
0.1
0.01
1
2
50 100
5
10
20
MOSFET CURRENT (1 = SET CURRENT)
1155 F02
Figure 2. Shutdown Time vs MOSFET Current
In the example presented above, we established that the
power MOSFET should not be allowed to pass 62.5A for
more than 10ms. 62.5A is roughly 18 times the set current of 3.3A. By drawing a line up from 18 and reflecting
it off the curve, we establish that the RC time constant
should be set at 10ms divided by 0.054, or 180ms. Both
methods result in the same conclusion.
Large inductive loads, such as solenoids, relays and motors store energy which must be directed back to either
the power supply or to ground when the supply voltage is
interrupted (see Figure 4). In normal operation, when the
switch is turned OFF, the energy stored in the inductor is
harmlessly absorbed by the MOSFET; i.e., the current flows
out of the supply through the MOSFET until the inductor
current falls to zero.
+
+
VS
IN1
Using a Speed Up Diode
DS1
CDLY
RSEN
0.025Ω
RDLY
LTC1155
GND
A way to further reduce the amount of time that the power
MOSFET is in a short-circuit condition is to “bypass”the
delay resistor with a small signal diode as shown in Figure 3. The diode will engage when the drop across the
drain sense resistor exceeds 0.7V, providing a direct path
CS
G1
IRLZ34
L LOAD
GND
1155 F04
Figure 4. Switched Supply
Rev. C
8
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LTC1155
APPLICATIONS INFORMATION
If the MOSFET is turned ON and the power supply (battery)
removed, the inductor current is delivered by the supply
capacitor. The supply capacitor must be large enough to
deliver the energy demanded by the discharging inductor.
If the storage capacitor is too small, the supply lead of
the LTC1155 may be pulled below ground, permanently
destroying the device.
Consider the case of a load inductance of 1mH which
is supporting 3A when the 6V power supply connection
is interrupted. A supply capacitor of at least 250µF is
required to prevent the supply lead of the LTC1155 from
being pulled below ground (along with any other circuitry
tied to the supply).
Any wire between the power MOSFET source and the load
will add a small amount of parasitic inductance in series
with the load (approximately 0.4µH/foot). Bypass the power
supply lead of the LTC1155 with a minimum of 10µF to
ensure that this parasitic load inductance is discharged
safely, even if the load is otherwise resistive.
Overvoltage Protection
The MOSFET and load can be protected against overvoltage conditions by using the circuit of Figure 6. The drain
sense function is used to detect an overvoltage condition
and quickly discharge the power MOSFET gate. The 18V
zener diode conducts when the supply voltage exceeds
18.6V and pulls the drain sense pin 0.6V below the supply pin voltage.
The supply voltage is limited to 18.6V and the gate drive is
immediately removed from the MOSFET to ensure that it
cannot conduct during the overvoltage period. The gate of
the MOSFET will be latched OFF until the supply transient
is removed and the input turned OFF and ON again.
VS = 4.5V TO 18V
VS
Large Inductive Loads
IN1
Large inductive loads (>0.1mH) may require diodes connected directly across the inductor to safely divert the
stored energy to ground. Many inductive loads have these
diodes included. If not, a diode of the proper current rating should be connected across the load to safely divert
the stored energy.
RSEN
CDLY
RDLY
DS1
+
LTC1155
100k
10µF
25V
G1
GND
5V
300Ω
1/4W
LOAD
GND
1155 F05
Figure 5. Reverse Battery Protection
Reverse-Battery Protection
VS = 4.5V TO 18V
The LTC1155 can be protected against reverse-battery
conditions by connecting a resistor in series with the
ground lead as shown in Figure 5. The resistor limits the
supply current to less than 50mA with –12V applied. Since
the LTC1155 draws very little current while in normal
operation, the drop across the ground resistor is minimal.
The TTL or CMOS driving logic is protected against
reverse-battery conditions by the 100k input current
limiting resistor. The addition of 100k resistance in series
with the input pin will not affect the turn ON and turn OFF
times which are dominated by the controlled gate charge
and discharge periods.
510Ω
10k
VS
IN1
1N4148
DS1
LTC1155
GND
G1
18V
LOAD
GND
1155 F06
Figure 6. Overvoltage Shutdown and Protection
Rev. C
For more information www.analog.com
9
LTC1155
TYPICAL APPLICATIONS
Dual 2A Autoreset Electronic Fuse
5V
+
0.1µF
0.03Ω
10µF
0.1µF
30k
DS1
G1
1/2 SI9956DY
8
4
LMC555
3 fO = 1Hz
1N4148
750k
1N4148
0.03Ω
30k
VS
DS2
G2
1/2 SI9956DY
LTC1155
100k
IN1
100k
IN2
GND
2
6
OUT 1
1
OUT 2
1.0µF
ALL COMPONENTS SHOWN ARE SURFACE MOUNT
1155 TA03
High Side Driver with VDS Sense Short-Circuit Shutdown
4.5V TO 6V
+
10µF
30k
VS
5V
*
IN1
DS1
1/2
LTC1155
GND
IRLZ24
G1
0.01µF
270k
LOAD
*ANY 74C OR 74HC LOGIC GATE.
MOSFET SHUTS DOWN IF VDS > 1V
1155 TA04
Rev. C
10
For more information www.analog.com
LTC1155
TYPICAL APPLICATIONS
X-NOR Fault Detection
4.5V TO 6V
+
10µF
0.1Ω
VS
DS1
1/2
LTC1155
IN1
10k
IRLD024
G1
GND
100k
FAULT
LOAD
74C266
1155 TA05
Truth Table
IN
OUT
CONDITION
FLT
0
1
0
Switch OFF
1
0
Short Circuit
0
0
1
Open Load
0
1
1
Switch ON
1
Low Side Driver with Source End Current Sensing
Low Side Driver with Drain End Current Sensing
5V
+
5V
10µF
0.05Ω
5%
VS
IN1
10µF
51Ω
VS
DS1
1/2
LTC1155
GND
+
LOAD
G1
VLOAD
IN1
SMP25N05
LOAD
DS1
1/2
LTC1155
GND
SMP25N05
G1
7
1155 TA06
6
+
LT®1077*
51Ω
4
–
3
2
0.02Ω
5%
1155 TA07
*DO NOT SUBSTITUTE. MUST BE A PRECISION, SINGLE
SUPPLY, MICROPOWER OP AMP (IQ < 60µA)
Rev. C
For more information www.analog.com
11
LTC1155
TYPICAL APPLICATIONS
Automotive High Side Driver with Reverse-Battery
and High Voltage Transient Protection
9V TO 16V
+
CDLY**
10µF
VS
5V
100k*
IN1
RDLY**
DS1
18V
1N4746A
1/2
LTC1155
GND
0.02Ω
5%
MTP50N05E
G1
18V
1N4746A
300Ω
1/4W
VALVE,
ETC.
M
1155 TA08
*PROTECTS TTL/CMOS GATES DURING HIGH VOLTAGE
TRANSIENT OR REVERSE BATTERY
**NOT REQUIRED FOR INDUCTIVE OR RESISTIVE LOADS
Using the Second Channel for Fault Detection
4.5V TO 5.5V
+
100k
FLT
µP OR
CONTROL
LOGIC
ON/OFF
0.1µF*
10µF
DS1
1N4148
1N4148
100k
G2
VS
30k*
DS2
LTC1155
SMD25N05-45L
IN2
IN1
0.05Ω
GND
G1
LOAD
NOTE:
DRAIN SENSE 2 IS USED TO DETECT A FAULT IN CHANNEL 1.
GATE 2 PULLS DOWN ON DRAIN SENSE 1 TO DISCHARGE
THE MOSFET AND REPORT THE FAULT TO THE µP
1155 TA10
*NOT REQUIRED FOR RESISTIVE OR INDUCTIVE LOADS
Rev. C
12
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LTC1155
TYPICAL APPLICATIONS
5V/3A Extremely Low Voltage Drop Regulator with 10µA Standby
Current and Short-Circuit Protection
5.2V TO 6V
+
10µF
0.1µF
300k
VS
IN1
ON/OFF
0.02Ω
DS1
1/2
LTC1155
100k
G1
GND
IRLR024
200pF
FAULT
10k
0.1µF
1
8
3
LT1431
7
6
4
5V/3A
+
5
*CAPACITOR ESR SHOULD BE LESS THAN 0.5Ω
470µF*
1155 TA09
Bootstrapped Gate Drive for (100Hz < FO < 10kHz)
9V TO 18V
0.01µF
5V
VS
µP OR
CMOS/TTL
LOGIC
IN1
DS1
1N4148
0.01Ω
30k
1/2
LTC1155
GND
G1
2N2222
0.1µF
IRFZ44
VGATE = 2VS – 0.6V
18V
2N3906
RISE AND FALL TIMES ARE βETA TIMES FASTER
LOAD
1155 TA11
Rev. C
For more information www.analog.com
13
LTC1155
TYPICAL APPLICATIONS
Logic Controlled Boost Mode Switching Regulator with Short-Circuit Protection and 8µA Standby Current
4.75V TO 5.25V
+
0.33µF
100µF
VS
FROM µP, ETC.
0.02Ω
100k
DS1
1/2
LTC1155
IN1
MTM25N05L
G1
GND
FAULT
1N5820
50µH*
1N4148
5V SWITCHED
12V/1A
5
68µF
1
+
LT1170
1k
4
10.7k
1%
2
3
+
2200µF
1.24k
1%
1µF
*COILTRONICS CTX-7-52
1155 TA12
High Efficiency 60Hz Full-Wave Synchronous Rectifier
**
100k
10k
12.6VCT
110V AC
10Ω
2
3
–
+
18V
1N4746A
1N4148
DS1
IN1
7
LT1006
6
S
1N4148
VS
IRFZ44*
9V/3A
DC
D
DS2
G1
+
LTC1155
1N4148
IN2
4
4700µF
16V
G2
GND
1N4148
0.03Ω
+
10k
10µF
100k
1N4001
18V
1N4746A S
**
MOSFETs ARE SYNCHRONOUSLY ENHANCED WHEN RECTIFIER CURRENT EXCEEDS 300mA
*NO HEATSINK REQUIRED. CASES (DRAINS) CAN BE TIED TOGETHER
**INTERNAL BODY DIODE OF MOSFET
D
IRFZ44*
1155 TA13
Rev. C
14
For more information www.analog.com
LTC1155
TYPICAL APPLICATIONS
High Efficiency 60Hz Full-Wave Synchronous Rectifier
9V/3A
DC
10k
110V AC
6.3V AC
2
3
100k
1N4148
–
+
DS2
IN1
7
6
LT1006
VS
DS1
G1
**
LTC1155
1N4148
IN2
4
10k
4 × IRFZ44*
D
S
D
S
S
S
D
**
+
4700µF
16V
G2
GND
**
**
18V
1N4746A
18V
1N4746A
100k
10Ω
D
0.03Ω
1155 TA14
MOSFETs ARE SYNCHRONOUSLY ENHANCED WHEN RECTIFIER CURRENT EXCEEDS 300mA
*NO HEATSINK REQUIRED
**INTERNAL BODY DIODE OF MOSFET
Push-Pull Driver with Shoot-Through Current Lockout (fO < 100Hz)
4.5V TO 6V
5V
100k
0.01Ω
0.1µF
300k
10µF
100k
DS1
IN1
HI/LO
74HC02
VS
DS2
G1
*
IRLZ24
LTC1155
IN2
VOUT
G2
GND
*
IRFZ24
1N4148
1N4148
1155 TA15
*OPPOSING GATE MUST DROP BELOW 2V BEFORE THE OTHER IS CHARGED
Rev. C
For more information www.analog.com
15
LTC1155
TYPICAL APPLICATIONS
Full H-Bridge Driver with Shoot-Through Current Lockout and Stall Current Shutdown (fO < 100Hz)
4.5V TO 6V
10µF
0.1µF
0.01Ω
100k
5V
DIRECTION
74HC02
DS1
IN1
VS
DS2
G1
IN2
IRLZ44
*
LTC1155
VN2222L
G2
IRLZ44
M
GND
DISABLE
*
IRFZ44
IRFZ44
VN2222L
1155 TA16
*OPPOSING GATES ARE HELD OFF UNTIL OTHER GATES DROP BELOW 1.5V
DC Motor Speed and Torque Control for Cordless Tools and Appliances
+
100Ω
6V
0.1µF
+
47µF
16V
300k
1M
1.1k
0.1Ω
10k
TORQUE
ADJUST
1M
+
100k
DS1
IN1
1/2
LT1017
–
1M
1M
10k
SPEED
ADJUST
120k
+
1/2
LT1017
DS2
G1
IRFZ24
LTC1155
IN2
–
0.0033µF
VS
1A TO
10A
MAX
G2
GND
SMALL DC APPLIANCE
OR TOOL MOTOR
M
100k
1155 TA17
SPEED IS PROPORTIONAL TO PULSE WIDTH. TORQUE IS PROPORTIONAL TO CURRENT
Rev. C
16
For more information www.analog.com
LTC1155
PACKAGE DESCRIPTION
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION
(4 PLCS)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.005
(0.127)
MIN
.405
(10.287)
MAX
8
7
6
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
.300 BSC
(7.62 BSC)
2
3
4
.200
(5.080)
MAX
.015 – .060
(0.381 – 1.524)
.008 – .018
(0.203 – 0.457)
0° – 15°
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
.045 – .065
(1.143 – 1.651)
.014 – .026
(0.360 – 0.660)
.100
(2.54)
BSC
.125
3.175
MIN
J8 0801
OBSOLETE PACKAGE
Rev. C
For more information www.analog.com
17
LTC1155
PACKAGE DESCRIPTION
N Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
.300 – .325
(7.620 – 8.255)
.008 – .015
(0.203 – 0.381)
(
+.035
.325 –.015
8.255
+0.889
–0.381
.045 – .065
(1.143 – 1.651)
.065
(1.651)
TYP
.400*
(10.160)
MAX
.130 ±.005
(3.302 ±0.127)
8
7
6
1
2
3
5
.255 ±.015*
(6.477 ±0.381)
)
.120
(3.048) .020
MIN
(0.508)
MIN
.018 ±.003
.100
(2.54)
BSC
4
N8 REV I 0711
(0.457 ±0.076)
NOTE:
1. DIMENSIONS ARE
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
.050 BSC
.245
MIN
(Reference LTC DWG # 05-08-1610 Rev G)
.045 ±.005
.160 ±.005
.030 ±.005
TYP
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
× 45°
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
.053 – .069
(1.346 – 1.752)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
NOTE:
1. DIMENSIONS IN
.189 – .197
(4.801 – 5.004)
NOTE 3
.014 – .019
(0.355 – 0.483)
TYP
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
8
7
6
5
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
SO8 REV G 0212
1
2
3
4
Rev. C
18
For more information www.analog.com
LTC1155
REVISION HISTORY
(Revision history begins at Rev C)
REV
DATE
DESCRIPTION
C
05/19
Obsoleted CERDIP J8 package
PAGE NUMBER
2, 17
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
subject to change without notice. No license is
granted
implication orwww.analog.com
otherwise under any patent or patent rights of Analog Devices.
For
morebyinformation
19
LTC1155
TYPICAL APPLICATIONS
Isolated High Voltage High Side Switch with Circuit Breaker
6V TO 12V
1N5817
1N4148
0.1µF
200V
1/6 74C14
1k
+
1N4148
100pF
90V
4N28
B
100k
1k
C
10mA
CONTROL
E
DS1
IN1
10µF
25V
VS
DS2
G1
6A MAX
LTC1155
1N5817
IN2
G2
1k
2N2222
GND
18V
1N4746A
1M
0.1Ω
M
MUR420
1155 TA18
Isolated Solid-State AC Relay with Circuit Breaker
18V
1N4746A
IN/OUT
18V
1N4746A
IRFZ24
5V
0.1µF
1/6 74C14
100k
0.0022µF
100k
300Ω
600Ω
+
DS1
IN1
1µF
IN2
1/6 74C14
T1*
VS
0.05Ω
100k
DS2
G1
IRFZ24
LTC1155
1N4148
ON/OFF
0.01µF
5.6V
1N4690A
1N5817
100k
GND
IN/OUT
24V AC
2A MAX
G2
EQUIVALENT FUNCTION
IN/OUT
*PICO ELECTRONICS F-28115 OR EQUIVALENT
ON/OFF
IN/OUT
2A
1155 TA19
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1153
Auto-Reset Electronic Circuit Breaker
Programmable Trip Current, Fault Status Output
LT1161
Quad Protected High Side MOSFET Driver
8V to 48V Supply Range, Individual Short-Circuit Protection
LTC1163
Triple 1.8V to 6V High Side MOSFET Driver
0.01µA Standby Current, Triple Driver in SO-8 Package
LTC1255
Dual 24V High Side MOSFET Driver
Operates from 9V to 24V, Short-Circuit Protection
LTC1477
Protected Monolithic High Side Switch
Low RDS(ON) 0.07Ω Switch, 2A Short-Circuit Protected
LTC1623
SMBus Dual High Side Switch Controller
2-Wire SMBus Serial Interface, Built-In Gate Charge Pumps
LTC1710
SMBus Dual Monolithic High Side Switch
Two Low RDS(ON) 0.4Ω/300mA Switches in 8-Lead MSOP Package
LT1910
Protected High Side MOSFET Driver
8V to 48V Supply Range, Fault Status Output
Rev. C
20
05/19
www.analog.com
For more information www.analog.com
ANALOG DEVICES, INC. 1991