LTC1981/LTC1982
Single and Dual Micropower
High Side Switch Controllers
in SOT-23
FEATURES
DESCRIPTIO
n
No External Components Required The LTC 1981/LTC1982 are low-power, self-contained
n
Internal Voltage Triplers Produce High Side N-channel MOSFET drivers. An internal voltage tripler
Gate Drive for Logic Level FETs allows gates to be driven without the use of any external
n
Ultralow Power: components. Internal regulation circuitry allows quies-
10m A Per Driver ON Current (LTC1982) cent current to drop to 10m A per driver (20m A for LTC1981)
20m A ON Current (LTC1981) once the gates are charged.
<1m A Shutdown Current
Low quiescent current and low shutdown current (under
n
V Range: 1.8V to 5V
CC
1m A) make these parts ideal for battery and other power
n
Gate Drive Outputs Driven to Ground During
constrained systems. The wide input voltage range ac-
Shutdown
commodates a variety of battery/input configurations.
n
Gate Drive Outputs Internally Clamped to 7.5V Max
n Gate drive is internally clamped to 7.5V providing protec-
Gate Drive Ready Output (LTC1981)
n tion to the external MOSFET gate. The MOSFETs can be
Ultrasmall Application Circuit
n driven in either high side or low side mode.
5-Pin SOT-23 Package (LTC1981)
n
6-Pin SOT-23 Package (LTC1982)
The LTC1981 single driver version also includes a gate
U
drive ready pin and twice the drive current capacity of the
APPLICATIO S
dual driver LTC1982.
n
Cellular Telephones
The LTC1981 is available in a 5-pin SOT-23. The LTC1982
n
Portable POS Terminal
is available in a 6-pin SOT-23.
n
Handheld Battery Powered Equipment
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIONS
Single High Side Switch Controller
Dual High Side Switch Controller
V V
CC CC
1.8V TO 5.0V 1.8V TO 5.0V
Q1
Q1
+
+
Si3442DV 1/2 Si6925DQ
10m F
10m F
Q2
1/2 Si6925DQ
54 654
V GATE V GATE 1 GATE 2
CC CC
100k LTC1981 LOAD LTC1982 LOAD 1 LOAD 2
GDR GND SHDN SHDN 1 GND SHDN 2
GATE
123 123
DRIVE
READY
SHDN 1
SHDN 1981/82 TA01 1981/82 TA02
SHDN 2
1
U
ULTC1981/LTC1982
ABSOLUTE AXI U RATI GS
(Notes 1, 2)
Terminal Voltage Operating Temperature Range
LTC1981: V , GATE, SHDN, GDR ........ 0.3V to 7.5V LTC1981E/LTC1982E (Note 3) ............ 40 C to 85 C
CC
LTC1982: V , GATE 1, GATE 2, Storage Temperature Range ................. 65 C to 150 C
CC
SHDN 1, SHDN 2 ................... 0.3V to 7.5V Lead Temperature (Soldering, 10 sec).................. 300 C
UUW
PACKAGE/ORDER I FOR ATIO
ORDER PART ORDER PART
TOP VIEW
NUMBER NUMBER
TOP VIEW
GDR 1 5 V
CC SHDN 1 1 6 V
CC
LTC1981ES5 LTC1982ES6
GND 2
GND 2 5 GATE 1
SHDN 3 4 GATE
SHDN 2 3 4 GATE 2
S5 PART S6 PART
S5 PACKAGE
S6 PACKAGE
MARKING MARKING
5-LEAD PLASTIC SOT-23
6-LEAD PLASTIC SOT-23
T = 150 C, q = 250 C/W
T = 150 C, q = 230 C/W
JMAX JA JMAX JA
LTSF LTPF
Consult factory for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25 C. V = 5V unless otherwise specified. C = C = C = 1000pF.
A CC GATE 1 GATE 2 GATE
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V Operating Supply Voltage l 1.8 5.5 V
CC
I Supply Current GATE 1 and GATE 2 Outputs High l 17 30 m A
CC
GATE 1 or GATE 2 Outputs High l 10 20 m A
GATE Output High (LTC1981) l 17 30 m A
I SHDN Supply Current SHDN 1 and SHDN 2 Inputs Low l 1 m A
SHDN
SHDN Input Low (LTC1981) l 1 m A
V GATE Drive Output Voltage V = 1.8V l 4.27 4.50 4.75 V
GATE CC
V = 2.7V l 6.40 6.75 7.10 V
CC
V = 3.3V l 6.90 7.25 7.50 V
CC
V = 5V l 6.90 7.25 7.50 V
CC
f Charge Pump Oscillator Frequency Measured with 10k Resistor from Output to GND 600 kHz
OSC
t Turn-on Time into 1000pF From SHDN 1, SHDN 2 Going High to
ON
GATE 1, GATE 2 = V + 1V 110 m s
CC
From SHDN Going High to GATE = V +1V (LTC1981) 85 m s
CC
t Turn-off Time into 1000pF From SHDN 1, SHDN 2 Going Low to
OFF
GATE 1, GATE 2 GATE = 100mV 12 m s
,
V SHDN Input Low Voltage V = 1.8V to 5.5V l 0.4 V
IL CC
V SHDN Input High Voltage V = 1.8V to 5.5V l 1.6 V
IH CC
C SHDN Input Capacitance (Note 4) 5 pF
IN
I SHDN Input Leakage Current 1 m A
IN
2
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