MAX13487E/MAX13488E

Half-Duplex RS-485-/RS-422-

Compatible Transceiver with

AutoDirection Control

Maxim Integrated | 11

www.maximintegrated.com

Pin Description

PIN

NAME

FUNCTION

1RO

Receiver Output. When receiver is enabled and V(A) - V(B) > +200mV, RO is high. If V(A) - V(B)

< -200mV, RO is low.

2

RE

Receiver Output Enable. Drive

RE low to enable the RO. Drive RE high to let the AutoDirection circuit

control the receiver.

RE is a hot-swap input (see the Hot-Swap Capability section for more details).

3

SHDN

Shutdown. Drive

SHDN high to let the device operate in normal operation. Drive SHDN low to put the part

in shutdown.

4DI

Driver Input. Drive DI low to force noninverting output low and inverting output high. Drive DI high to force

noninverting output high and inverting output low. DI is an input to the internal state machine that

automatically enables and disables the driver. See the Function Tables and General Description for more

information. DI is a hot-swap input (see the Hot-Swap Capability section for more details).

5

GND

Ground

6

A

Noninverting Receiver Input and Noninverting Driver Output

7

B

Inverting Receiver Input and Inverting Driver Output

TRANSMITTING

INPUTS

OUTPUTS

SHDN

DI

ACTION

A

B

1

0

X

Turn driver ON

0

1

1

1

False

If driver was OFF, keep it OFF

HIGH IMPEDANCE

HIGH IMPEDANCE

1

1

False

If driver was ON, keep it ON

1

0

1

1

True

Turn driver OFF

HIGH IMPEDANCE

HIGH IMPEDANCE

0

X

X

X

SHUTDOWN

RECEIVING

INPUTS

OUTPUT

SHDN

RE

A-B

DRIVER STATE

RECEIVER STATE

RO

10

≥+200mV

X

ON

1

10

≤-200mV

X

ON

0

1

1

X

ON

OFF

HIGH IMPEDANCE

11

≥+200mV

OFF

ON

1

11

≤-200mV

OFF

ON

0

0

X

X

X

X

SHUTDOWN

Function Tables

X = Don’t care, shutdown mode, driver, and receiver outputs are in high impedance.