±15kV ESD-Protected, ±60V Fault-Protected,

10Mbps, Fail-Safe RS-485/J1708 Transceivers

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11

Function Tables

INPUTS

OUTPUTS

A-B

INPUT VOLTAGE

COMMON-MODE

VOLTAGE

RO

FAULT

CONDITIONED

BY DELAY

FAULT CONDITION

≥0.45V

1

0

Normal operation

<0.45V and

≥0.27V

1

Indeterminate

Indeterminate

<0.27V and

≥-0.05V

1

1

Low-input differential voltage

≤-0.05V and ≥-0.2V

Indeterminate

(Note 1)

1

Low-input differential voltage

≤-0.2V and >-0.27V

0

1

Low-input differential voltage

≤-0.27V and >-0.45V

0

Indeterminate

≤-0.45V

≤12V and ≥-7V

00

Indeterminate

X

<-7V or >+12V

Indeterminate

1

Outside common-mode voltage range

Table 1. MAX3440E/MAX3441E Fault Table

X = Don’t care.

Note 1: Receiver output may oscillate with this differential input condition.

TRANSMITTING

INPUTS

OUTPUTS

DE/RE

DI

A

B

0

X

High-Z

High-Z

10

01

11

10

Table 2. MAX3440E/MAX3441E

(RS-485/RS-422)

X = Don’t care.

TRANSMITTING

INPUTS

OUTPUTS

RE

DE

DI

A

B

0

0

X

High-Z

High-Z

01

001

01

110

1

0

X

Shutdown

Shutdown

11

001

11

110

Table 3. MAX3442E/MAX3443E

(RS-485/RS-422)

X = Don’t care.

TRANSMITTING

INPUTS

OUTPUTS

CONDITIONS

TXD

DE

AB

—

0

1

High-Z

High-Z

—

1

1

High-Z

High-Z

—

0

0

1

0

Dominant state

1

0

High-Z

High-Z

Recessive state

Table 4. MAX3444E (J1708) Application

RECEIVING

INPUTS

OUTPUTS

DE/RE

(A - B)

RO

0

≥-0.05V

1

0

≤-0.2V

0

0

Open/shorted

1

1

X

High-Z

Table 5. MAX3440E/MAX3441E

(RS-485/RS-422)

X = Don’t care.