Datasheet

6
LTC1163/LTC1165
APPLICATIO S I FOR ATIO
W
U
U
U
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
U
PCMCIA Card 3.3V/5V V
CC
Switch
V
S
LTC1165
OUT1
OUT2
OUT3
GND
IN1
IN2
IN3
V
CC
5V
V
CC
3V
PCMCIA
CONTROLLER
+
10µF
5V
PC
CARD
SOCKET
MMDF3N02HD
+
1µF
1/2 MMDF3N02HD
V
CC
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 150Ω 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 (or control logic) can be protected by
adding 10k resistors in series with the input pins.
Figure 2. Direct Interface to 5V Logic
V
S
1/3 LTC1163
OUT1
GND
IN1
ON/OFF
R1
100k
R2
1k
C1
0.1µF
3.3V
LOAD
+
C
L

100µF
V
IN
LT1129-3.3
3.3µF
+
MTD3055EL
3.3V
LTC1163/65 • F01
V
S
1/3 LTC1163
OUT1
GND
IN1
3.3V
LOAD
3.3V
MTD3055EL
LTC1163/65 • F01
5V