LTC1155_15 Datasheet, PDF (1/16 Pages) Linear Technology – Dual High Side Micropower MOSFET Driver

LTC1155
Dual High Side
Micropower MOSFET Driver
FEATURES
n _{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}
APPLICATIONS
n _{Laptop Power Bus Switching}
n _{SCSI Termination Power Switching}
n _{Cellular Phone Power Management}
n _{P-Channel Switch Replacement}
n _{Relay and Solenoid Drivers}
n _{Low Frequency Half H-Bridge}
n _{Motor Speed and Torque Control}
DESCRIPTION
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 posi-
tive 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.
Included on-chip is overcurrent sensing to provide au-
tomatic 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.
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) applica-
tions, particularly where micropower “sleep” operation
is required.
The LTC1155 is available in both 8-pin PDIP and 8-pin
SO packages.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
Laptop Computer Power Bus Switch with Short-Circuit Protection
R_SEN
0.02Ω
R_DLY
100k
V_S = 4.5V TO 5.5V
C_DLY
0.1µF
+
10µF
DS1
V_S
DS2
C_DLY
0.1µF
R_DLY
100k
R_SEN
0.02Ω
*IRLR034
5A
MAX
TTL, CMOS INPUT
G1 LTC1155 G2
IN1 GND IN2
*IRLR034
5A
MAX
TTL, CMOS INPUT
POWER BUS
µP
SYSTEM
DISK
DRIVE
GND
*SURFACE MOUNT
DISPLAY
PRINTER,
ETC.
1155 TA01
For more information www.linear.com/LTC1155
0.25
0.20
0.15
0.10
0.05
0.00
0
Switch Voltage Drop
1
2
OUTPUT CURRENT (A)
3
1155 TA02
1155fb
1