Datasheet

LTC1696
10
APPLICATIO S I FOR ATIO
WUUU
Back-to-Back N-Channel MOSFET
A power management circuit that uses the LTC1696 to
control external back-to-back N-channel MOSFET at low
supply voltage is shown in Figure 3. In standby mode, the
drain of the external N-channel MOSFET, Q1, is pulled high
by the power management controller when the LTC1696
OUT pin is in the low state. The LTC1696 drives the gate of
Q1 high during an overvoltage fault condition. This pulls
the drain of Q1 low and turns off the back-to-back N-
channel MOSFETs.
C1
1nF
6
5
4
1696 F03
1
2
3
LTC1696
RESET
1.8V
Q2
2N7002
FB1
GND
V
CC
FB2
OUT
TIMER/
RESET
R1
44.2k
1%
1.5V
V
CC
3.3V
R2
38.3k
1%
R3
44.2k
1%
Q1
2N7002
N-CHANNEL
×2
PRIMARY
INPUT
SUPPLY
R4
54.9k
1%
C2
0.1µF
POWER MANAGEMENT
CONTOLLER
Figure 3. Back-to-Back N-Channel MOSFETs for Low Supply Application