1

Ω, Low-Voltage, Single-Supply

SPDT Analog Switches

6

_______________________________________________________________________________________

Pin Description

Detailed Description

low-voltage, single-pole/double-throw (SPDT) analog

switches that operate from a +1.8V to +5.5V supply.

The MAX4624 has break-before-make switching, and

the MAX4625 has make-before-break switching. These

When powered from a +5V supply, their 1

allows high continuous currents to be switched in a

variety of applications. In an overcurrent condition,

these switches provide both current-limit and thermal-

shutdown protection.

Current-Limit Protection

The MAX4624/MAX4625 feature current-limit protection

circuitry. When the voltage drop across the on switch

reaches 0.6V typ, the internal circuitry activates. The

current limit is not instantaneous, but rather integrates

over time, so current limiting will not activate when the

switch output charges a small 0.1µF capacitor. For sus-

tained overload conditions, the switch turns off (opens).

The switch turns on after 5ms. If the overload persists,

the switch cycles off and on to produce a pulsed out-

put. A direct short circuit will be detected immediately,

and the switch will pulse on for 1µs, then remain off for

5ms.

Applications Information

Logic Inputs

The MAX4624/MAX4625 logic inputs can be driven up

to +5.5V regardless of the supply voltage. For example,

with a +3.3V supply, IN may be driven low to 0V and

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.

Power-Supply Sequencing and

Overvoltage Protection

Caution: Do not exceed the absolute maximum rat-

ings because stresses beyond the listed ratings

may cause permanent damage to the devices.

Proper power-supply sequencing is recommended for

all CMOS devices. Always apply V+ before applying

analog signals, especially if the analog signal is not

current limited. If this sequencing is not possible, and if

the analog inputs are not current limited to <20mA, add

Analog Switch—Common

COM

5

Analog Switch—Normally Open

NO

6

Analog Switch—Normally Closed

NC

4

Ground

GND

3

PIN

Positive Supply Voltage Input

V+

2

Digital Control Input

IN

1

FUNCTION

NAME

POSITIVE SUPPLY

COM

NO

D2

D1

GND

Vg

V+

MAX4624

MAX4625

Figure 1. Overvoltage Protection Using Two External Blocking

Diodes

Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.