Battery Switch with

Back-to-Back MOSFETs

For battery-operated applications, use back-to-back

MOSFETs to keep reverse currents from flowing from

the load to the supply (Figure 7). This protects the bat-

tery from potential damage, and isolates the load from

the power source.

LED Drivers

A MAX1661/MAX1662/MAX1663 can be used as a pro-

grammable LED driver (Figure 8). With their low quies-

cent current, these devices are ideal for use as

indicator light drivers on the front panel of a notebook

computer.

Serial-to-Parallel/Parallel-to-Serial Converters and

Load-Switch Controllers with SMBus Interface

12

______________________________________________________________________________________

MAX1662

MAX1663

I/O1

TO/FROM

HOST

+5V

+3.3V TO +28V

P

P

I/O3

I/O2

GND

LOAD

ALERT

0.1

µF

100k

IRF7406

IRF7406

SMBCLK

SMBDATA

SMBSUS

ADD

100

Ω*

10k

10k

10k

75k**

NOTE: I/O2 AND I/O3 CAN BE CONFIGURED SIMILARLY.

*OPTIONAL

**75k

Ω RESISTOR FOR VOLTAGES GREATER THAN +12V.

1M

Figure 7. Battery Switch with Back-to-Back MOSFETs

MAX1661

MAX1662

MAX1663

I/O1

TO/FROM

HOST

+5V

I/O3

I/O2

GND

ALERT

0.1

µF

1k

1k

1k

SMBCLK

SMBDATA

SMBSUS

ADD

100

Ω*

*OPTIONAL

10k

10k

Figure 8. LED Drivers