4

LTC1163/LTC1165

CC

HARA TERISTICS

A

TYPICALPERFOR

CE

PI FU CTIO S

Input Pins

The LTC1163 is noninverting; i.e., the MOSFET gate is

driven above the supply when the input pin is held high.

The LTC1165 is inverting and drives the MOSFET gate high

when the input pin is held low. The inverting inputs of the

LTC1165 allow P-channel switches to be replaced by

lower resistance/cost N-channel switches while maintain-

ing system drive polarity.

The LTC1163/LTC1165 logic inputs are high impedance

CMOS gates with ESD protection diodes to ground and

therefore should not be forced below ground. The inputs

can however, be driven above the power supply rail as

there are no clamping diodes connected between the input

pins and supply pin. This facilitates operation in mixed

5V/3V systems.

Output Pins

The output pin is either driven to ground when the switch

is turned OFF or driven above the supply rail when the

switch is turned ON. The output is clamped to about 14V

above ground by a built-in Zener clamp. This pin has a

relatively high impedance when driven above the rail (the

equivalent of a few hundred k

Ω). Care should be taken to

minimize any loading of this pin by parasitic resistance to

ground or supply.

Supply Pin

A 150

Ω resistor should be inserted in series with the

ground pin or supply pin if negative supply voltage tran-

sients are anticipated. This will limit the current flowing

from the power source into the LTC1163/LTC1165 to tens

of milliamps during reverse battery conditions.

OPERATIO

The LTC1163/LTC1165 are triple micropower MOSFET

drivers designed for operation over the 1.8V to 6V supply

range and include the following functional blocks:

3V Logic Compatible Inputs

The LTC1163/LTC1165 inputs have been designed to

accommodate a wide range of 3V and 5V logic families.

The input threshold voltage is set at roughly 50% of the

supply voltage and approximately 200mV of input hyster-

esis is provided to ensure clean switching.

The input enables all of the following circuit blocks: the

bias generator, the high frequency oscillator and gate

charge pump. Therefore, when the input is turned off, the

entire circuit powers down and the supply current drops

below 1

µA.

Standby Supply Current

TEMPERATURE (°C)

0

5

4

3

2

1

0

–1

10

20

30

40

LTC1163/65 • TPC07

50

60

70

MOSFET Gate Drive Current

GATE VOLTAGE ABOVE SUPPLY (V)

1

10

100

1000

04

6

8

0.1

2

10

LTC1163/65 • TPC09

Supply Current per Driver ON

TEMPERATURE (°C)

0

300

250

200

150

100

50

0

10

20

30

40

LTC1163/65 • TPC08

50

60

70