6

LTC1163/LTC1165

APPLICATIO S I FOR ATIO

Figure 1. Powering a Large Capacitive Load

on a 3.3V supply which is compatible with 5V TTL and

CMOS logic. (The LTC1163/LTC1165 cannot however, be

driven by 3V logic when powered from a 5V supply

because the threshold is approximately 2.5V.)

TYPICAL APPLICATIO S

LTC1165

OUT1

OUT2

OUT3

GND

IN1

IN2

IN3

PCMCIA

CONTROLLER

+

10

µF

5V

PC

CARD

SOCKET

MMDF3N02HD

+

1

µF

1/2 MMDF3N02HD

3.3V

LTC1163/65 • TA03

NOTE: USE LTC1163 WITH NONINVERTING PCMCIA CONTROLLERS

managed by the system regulator. R2 is required to

eliminate the possibility of parasitic MOSFET oscillations

during switch transitions. It is a good practice to isolate the

gates of paralleled MOSFETs with 1k resistors to decrease

the possibility of interaction between switches.

Mixed 5V/3V Systems

Because the input ESD protection diodes are referenced to

ground instead of the supply pin, it is possible to drive the

LTC1163/LTC1165 inputs from 5V CMOS or TTL logic

even though the LTC1163/LTC1165 are powered from a

3.3V supply as shown in Figure 2. The input threshold

voltage is approximately 50% of the supply voltage or 1.6V

Reverse Battery Protection

The LTC1163/LTC1165 can be protected against reverse

battery conditions by connecting a 150

Ω resistor in series

with the ground pin or supply pin. The resistor limits the

supply current to less than 24mA with –3.6V applied.

Because the LTC1163/LTC1165 draw very little current

while in normal operation, the drop across the resistor is

minimal. The 3.3V

µP(orcontrollogic)canbeprotectedby

adding 10k resistors in series with the input pins.

Figure 2. Direct Interface to 5V Logic

1/3 LTC1163

OUT1

GND

IN1

ON/OFF

R1

100k

R2

1k

C1

0.1

µF

3.3V

LOAD

+

100

µF

LT1129-3.3

3.3

µF

+

MTD3055EL

3.3V

LTC1163/65 • F01

1/3 LTC1163

OUT1

GND

IN1

3.3V

LOAD

3.3V

MTD3055EL

LTC1163/65 • F01

5V