LTC1981/LTC1982
Single and Dual Micropower
High Side Switch Controllers
in SOT-23
FEATURES
s
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DESCRIPTIO
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s
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No External Components Required
Internal Voltage Triplers Produce High Side
Gate Drive for Logic Level FETs
Ultralow Power:
10碌A Per Driver ON Current (LTC1982)
20碌A ON Current (LTC1981)
<1碌A Shutdown Current
V
CC
Range: 1.8V to 5V
Gate Drive Outputs Driven to Ground During
Shutdown
Gate Drive Outputs Internally Clamped to 7.5V Max
鈥淕ate Drive Ready鈥?Output (LTC1981)
Ultrasmall Application Circuit
5-Pin SOT-23 Package (LTC1981)
6-Pin SOT-23 Package (LTC1982)
The LTC
廬
1981/LTC1982 are low-power, self-contained
N-channel MOSFET drivers. An internal voltage tripler
allows gates to be driven without the use of any external
components. Internal regulation circuitry allows quies-
cent current to drop to 10碌A per driver (20碌A for LTC1981)
once the gates are charged.
Low quiescent current and low shutdown current (under
1碌A) make these parts ideal for battery and other power
constrained systems. The wide input voltage range ac-
commodates a variety of battery/input configurations.
Gate drive is internally clamped to 7.5V providing protec-
tion to the external MOSFET gate. The MOSFETs can be
driven in either high side or low side mode.
The LTC1981 single driver version also includes a gate
drive ready pin and twice the drive current capacity of the
dual driver LTC1982.
The LTC1981 is available in a 5-pin SOT-23. The LTC1982
is available in a 6-pin SOT-23.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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Cellular Telephones
Portable POS Terminal
Handheld Battery Powered Equipment
TYPICAL APPLICATIONS
Single High Side Switch Controller
V
CC
1.8V TO 5.0V
Dual High Side Switch Controller
V
CC
1.8V TO 5.0V
+
10碌F
Q1
Si3442DV
+
10碌F
6
V
CC
5
LTC1982
SHDN 1
1
SHDN 1
GND
2
SHDN 2
3
4
5
V
CC
100k
GDR
GATE
DRIVE
READY
SHDN
1
LTC1981
GND
2
4
GATE
LOAD
SHDN
3
1981/82 TA01
SHDN 2
U
Q1
1/2 Si6925DQ
Q2
1/2 Si6925DQ
GATE 1 GATE 2
LOAD 1
LOAD 2
1981/82 TA02
U
U
1
1
2
3
4
5
6
7
8
