LTC1156
Quad High Side
Micropower MOSFET Driver
with Internal Charge Pump
DESCRIPTIO
The LTC1156 quad High side gate driver allows using low
cost N-channel FETs for high side switching applications.
An internal charge pump boosts the gate drive voltage
above the positive rail, fully enhancing an N-channel MOS
switch with no external components. Micropower opera-
tion, with 16µA standby current and 95µA operating
current, allows use in virtually all systems with maximum
efficiency.
Included on chip is independent over-current sensing to
provide automatic shutdown in case of short circuits. A
time delay can be added to the current sense to prevent
false triggering on high in-rush current loads.
The LTC1156 operates off of a 4.5V to 18V supply and is
well suited for battery-powered applications, particularly
where micropower “sleep” operation is required.
The LTC1156 is available in both 16-pin DIP and 16-pin
SOL packages.
FEATURES
s
s
s
s
s
s
s
s
s
No External Charge Pump Components
Fully Enhances N-Channel Power MOSFETs
16 Microamps Standby Current
95 Microamps ON Current
Wide Power Supply Range 4.5V to 18V
Controlled Switching ON and OFF Times
Replaces P-Channel High Side Switches
Compatible with Standard Logic Families
Available in 16-pin SOL Package
APPLICATI
s
s
s
s
s
s
s
S
Laptop Computer Power Switching
SCSI Termination Power Switching
Cellular Telephone Power Management
P-Channel Switch Replacement
Battery Charging and Management
Low Frequency H-Bridge Driver
Stepper Motor and DC Motor Control
TYPICAL APPLICATI
5V
Laptop Computer Power Management
100
+
10µF
V
S
5V
V
S
DS1
DS2
DS3
DS4
G1
G2
G3
G4
GND GND
0.1µF
100k
*30mΩ
SUPPLY CURRENT (µA)
Si9956DY
HARD DISK
DRIVE
FLOPPY DISK
DRIVE
LTC1156
IN1
CONTROL
LOGIC
OR
µP
IN2
IN3
IN4
Si9956DY
DISPLAY
PERIPHERAL
ALL COMPONENTS SHOWN ARE SURFACE MOUNT. MINIMUM PARTS COUNT
SHOWN. CURRENT LIMITS CAN BE SET SEPARATELY AND TAILORED TO
INDIVIDUAL LOAD CHARACTERISTICS.
* IMS026 INTERNATIONAL MANUFACTURING SERVICES, INC. (401) 683-9700
1156 TA01
U
UO
UO
Standby Supply Current
90
80
70
60
50
40
30
20
10
0
0
V
IN1
= V
IN2
= V
IN3
= V
IN4
= 0V
T
J
= 25°C
5
15
10
SUPPLY VOLTAGE (V)
20
LTC1156 G01
1
LTC1156
ABSOLUTE
AXI U
RATI GS
Operating Temperature Range
LTC1156C ............................................. 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)
Gate Voltage ....................... (V
S
+ 24V) to (GND – 0.3V)
Current (Any Pin)................................................. 50mA
PACKAGE/ORDER I FOR ATIO
TOP VIEW
GND
IN1
V
S
IN2
IN3
GND
IN4
V
S
1
2
3
4
5
6
7
8
16 G1
15 DS1
14 G2
13 DS2
12 DS3
11 G3
10 DS4
9
G4
ORDER PART
NUMBER
LTC1156CN
N PACKAGE
16-LEAD PLASTIC DIP
T
JMAX
= 110°C,
θ
JA
= 120°C/W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
S
I
Q
I
Q
I
Q
V
INH
V
INL
I
IN
C
IN
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
Drain Sense Threshold
Voltage
Drain Sense Input Current
(Note 1)
V
S
= 4.5V to 18V, T
A
= 25°C, unless otherwise noted.
MIN
q
CONDITIONS
V
S
= 5V, V
IN
= 0V (Note 2)
V
S
= 5V, V
IN
= 5V (Note 3)
V
S
= 12V, V
IN
= 5V (Note 3)
q
q
0V < V
IN
< V
S
0V < V
SEN
< V
S
V
S
= 5V
V
S
= 6V
V
S
= 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
V
GATE
– V
S
Gate Voltage Above Supply
t
ON
Turn-ON Time
2
U
U
W
W W
U
W
TOP VIEW
GND 1
IN1 2
V
S
3
IN2 4
IN3 5
GND 6
IN4 7
V
S
8
16 G1
15 DS1
14 G2
13 DS2
12 DS3
11 G3
10 DS4
9
S PACKAGE
16-LEAD PLASTIC SOL
T
JMAX
= 110°C,
θ
JA
= 130°C/W
ORDER PART
NUMBER
LTC1156CS
G4
TYP
MAX
18
UNITS
V
µA
µA
µA
V
4.5
16
95
180
2.0
40
125
400
0.8
±1.0
5
V
µA
pF
q
q
q
q
q
q
80
75
100
100
120
125
±0.1
mV
mV
µA
V
V
V
µs
µs
µs
µs
6.0
7.5
15
50
200
50
120
7.0
8.3
18
250
1100
180
450
9.0
15.0
25
750
2000
500
1200
LTC1156
ELECTRICAL CHARACTERISTICS
SYMBOL
t
OFF
PARAMETER
Turn-OFF Time
V
S
= 4.5V to 18V, T
A
= 25°C, unless otherwise noted.
MIN
10
10
5
5
TYP
36
26
16
16
MAX
60
60
30
30
UNITS
µs
µs
µs
µs
CONDITIONS
V
S
= 5V, C
GATE
= 1000pF
Time for V
GATE
< 1V
V
S
= 12V, C
GATE
= 1000pF
Time for V
GATE
< 1V
V
S
= 5V, C
GATE
= 1000pF
Time for V
GATE
< 1V
V
S
= 12V, C
GATE
= 1000pF
Time for V
GATE
< 1V
t
SC
Short Circuit Turn-OFF Time
The
q
denotes specifications which apply over the full operating
temperature range.
Note 1:
Both V
S
pins (3 and 8) must be connected together, and both
ground pins (1 and 6) must be connected together.
Note 2:
Quiescent current OFF is for all channels in OFF condition.
Note 3:
Quiescent current ON is per driver and is measured independently.
TYPICAL PERFOR A CE CHARACTERISTICS
Standby Supply Current
100
90
80
SUPPLY CURRENT (µA)
V
IN1
= V
IN2
= V
IN3
= V
IN4
= 0V
T
J
= 25°C
SUPPLY CURRENT (µA)
70
60
50
40
30
20
10
0
0
5
15
10
SUPPLY VOLTAGE (V)
20
LTC1156 G01
600
500
400
300
200
100
0
0
5
15
10
SUPPLY VOLTAGE (V)
20
1156 G02
V
GATE
– V
S
(V)
Standby Supply Current
100
90
80
V
IN1
= V
IN2
= V
IN3
= V
IN4
= 0V
1000
900
800
SUPPLY CURRENT (µA)
70
60
50
40
30
20
10
0
–50
25
V
S
= 5V
50
25
0
75
TEMPERATURE (°C)
100
125
V
S
= 18V
SUPPLY CURRENT (µA)
500
400
300
200
100
0
–50
25
V
S
= 5V
V
S
= 18V
V
GATE
(V)
U W
1156 G04
Supply Current per Channel ON
1000
900
800
700
ONE INPUT = ON
OTHER INPUTS = OFF
T
J
= 25°C
24
22
20
18
16
14
12
10
8
6
4
High Side Gate Voltage
0
5
15
10
SUPPLY VOLTAGE (V)
20
LTC1156 G03
Supply Current per Channel ON
30
Low Side Gate Voltage
27
24
21
18
15
12
9
6
3
ONE INPUT = ON
OTHER INPUTS = OFF
700
600
50
25
0
75
TEMPERATURE (°C)
100
125
0
0
2
6
8
4
SUPPLY VOLTAGE (V)
10
1158 G06
1156 G05
3
LTC1156
TYPICAL PERFOR A CE CHARACTERISTICS
Turn-ON Time
1000
900
800
TURN-ON TIME (µs)
C
GATE
= 1000pF
700
600
500
400
300
200
100
0
0
5
15
10
SUPPLY VOLTAGE (V)
20
1156 G07
TURN-OFF TIME (µs)
TURN-OFF TIME (µs)
V
GS
= 5V
V
GS
= 2V
BLOCK DIAGRA
V
S
ANALOG SECTION
100mV
REFERENCE
LOW STANDBY
CURRENT
REGULATOR
IN
TTL-TO-CMOS
CONVERTER
GND
OPERATIO
The LTC1156 contains four independent power MOSFET
gate drivers and protection circuits (refer to the Block
Diagram for detail). Each section of LTC1156 consists of
the following functional blocks:
4
U W
ANALOG
Turn-OFF Time
50
45
40
35
30
25
20
15
10
5
0
0
5
15
10
SUPPLY VOLTAGE (V)
20
1156 G08
Short Circuit Turn-OFF Delay Time
50
45
40
35
30
25
20
15
10
5
0
0
5
15
10
SUPPLY VOLTAGE (V)
20
1156 G09
C
GATE
= 1000pF
TIME FOR V
GATE
< 1V
C
GATE
= 1000pF
TIME FOR V
GATE
< 1V
V
SEN
= V
S
– 1V
NO EXTERNAL DELAY
W
DRAIN
SENSE
10µs
DELAY
COMP
DIGITAL
GATE CHARGE
AND DISCHARGE
CONTROL LOGIC
R
VOLTAGE
REGULATORS
ONE
SHOT
INPUT
LATCH
S
OSCILLATOR
AND CHARGE
PUMP
FAST/SLOW
GATE CHARGE
LOGIC
GATE
1156 BD
U
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.
LTC1156
OPERATIO
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 which generates a gate
voltage substantially higher than the power supply volt-
age. The charge pump capacitors are included on chip and
therefore no external components are required to generate
the gate drive.
TYPICAL APPLICATI
+
+
4-Cell Extremely Low Voltage Drop Regulator and Three Load
Switches with Short-Circuit Protection and 20µA Standby Current
5.2V TO 6V
4-CELL NiCd
BATTERY PACK
47µF
V
S
REG ON/OFF
CONTROL
LOGIC
FAULT
UO
U
Drain Current Sense
The LTC1156 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. A
simple RC network can be added to delay the over-current
protection so that large in-rush current loads such as
lamps or capacitors can be started.
Supply and Ground Pins
The two supply pins (3 and 8) of the LTC1156 must be
connected together at all times and the two ground pins (1
and 6) must be connected together at all times.
The two
supply pins should be connected to the “top” of the drain
current sense resistor/s to ensure accurate sensing.
For further applications information, see the LTC1155
Dual High Side Micropower MOSFET Driver data sheet.
S
0.1µF
100k
V
S
DS1
100k
G1
0.1µF
IN1
IN2
IN3
IN4
GND GND
10k
1N4148
8
7
* CAPACITOR ESR LESS THAN 0.5Ω
** RCS02 ULTRONIX (303) 242-0810
LTC1156
G2
G3
G4
200pF
DS2
DS3
DS4
**0.03Ω
3.3A MAX
IRLR024
5V/2A
SWITCHED
2
×
Si9956DY
1
3
LT1431
4
5V
LOAD
5V
LOAD
5V
LOAD
+
6
5
*470µF
1156 TA02
5
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