Detailed Description

The MAX4741/MAX4742/MAX4743 are low 0.8

Ω max

(at V+ = +3V) on-resistance, low-voltage, dual analog

switches that operate from a +1.6V to +3.6V single sup-

ply. CMOS switch construction allows switching analog

signals that are within the supply voltage range (GND

to V+).

When powered from a +3V supply, the 0.8

allows high continuous currents to be switched in a

variety of applications.

Applications Information

Proper power-supply sequencing is recommended for

all CMOS devices. Do not exceed the absolute maxi-

mum ratings, because stresses beyond the listed rat-

ings can cause permanent damage to the devices.

Always sequence V+ on first, followed by NO_, NC_, or

COM_.

Although it is not required, power-supply bypassing

improves noise margin and prevents switching noise

propagation from the V+ supply to other components.

A 0.1µF capacitor, connected from V+ to GND, is ade-

quate for most applications.

Logic Inputs

The MAX4741/MAX4742/MAX4743 logic inputs can be

driven up to +3.6V regardless of the supply voltage.

For example, with a +1.8V supply, IN_ may be driven

low to GND and high to +3.6V. Driving IN_ rail-to-rail

minimizes power consumption.

Analog Signal Levels

Analog signals that range over the entire supply voltage

(V+ to GND) can be passed with very little change in on-

resistance (see Typical Operating Characteristics). The

switches are bidirectional, so the NO_, NC_, and COM_

pins can be used as either inputs or outputs.

Layout

High-speed switches require proper layout and design

procedures for optimum performance. Reduce stray

inductance and capacitance by keeping traces short

and wide. Ensure that bypass capacitors are as close

to the device as possible. Use large ground planes

where possible.

0.8

Ω, Low-Voltage, Single-Supply Dual SPST

Analog Switches

_______________________________________________________________________________________

7

Pin Description

PIN

MAX4741

MAX4742

MAX4743

µMAX

SOT23-8

µMAX

SOT23-8

µMAX

SOT23-8

NAME

FUNCTION

18

——

1

8

NO1

Analog Switch 1 Normally Open

——

18

——

NC1

Analog Switch 1 Normally Closed

2

7

2

7

2

7

COM1

Analog Switch 1 Common

3

6

3

6

3

6

IN2

Logic Control Input Switch 2

4

5

4

5

4

5

GND

Ground

53

——

—

—

NO2

Analog Switch 2 Normally Open

——

5

3

5

3

NC2

Analog Switch 2 Normally Closed

6

4

6

4

6

4

COM2

Analog Switch 2 Common

7

1

7

1

7

1

IN1

Logic Control Input Switch 1

8

2

8

2

8

2

V+

Positive Supply Voltage