ISL32450E, ISL32452E, ISL32453E, ISL32455E, ISL32457E

4

FN7921.0

February 20, 2012

Pin Descriptions

PIN

NAME

ISL32450E,

ISL32453E,

(14 LD SOIC)

PIN #

ISL32450E,

ISL32453E,

(10 LD MSOP)

PIN #

ISL32452E,

ISL32455E

(8 LD SOIC,

8 LD MSOP)

PIN #

ISL32457E

(8 LD SOIC,

8 LD MSOP)

PIN #

FUNCTION

RO

2

1

1

1

Receiver output. For parts without the cable invert function - or if INV is low -

then: If A - B

≥ -10mV, RO is high; if A - B ≤ -200mV, RO is low. If INV is high, then:

If B - A

≥ -10mV, RO is high; if B - A ≤ -200mV, RO is low. In all cases, RO = High

if A and B are unconnected (floating), or shorted together, or connected to an

undriven, terminated bus (i.e., Rx is always failsafe open, shorted, and idle, even

if polarity is inverted).

RE

3

2

2

N/A

Receiver output enable. RO is enabled when RE is low; RO is high impedance

when RE is high. Internally pulled low.

DE

4

3

3

3

Driver output enable. The driver outputs, Y and Z, are enabled by bringing DE

high, and they are high impedance when DE is low. Internally pulled high.

DI

5

4

4

4

Driver input. For parts without the cable invert function - or if INV is low - a low

on DI forces output Y low and output Z high, while a high on DI forces output Y

high and output Z low. The output states, relative to DI, invert if INV is high.

GND

6, 7

5

5

5

Ground connection.

A/Y

N/A

N/A

6

6

±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 I/O pin. For

parts without the cable invert function - or if INV is low - A/Y is the non-inverting

receiver input and non-inverting driver output. If INV is high, A/Y is the inverting

receiver input and the inverting driver output. Pin is an input if DE = 0; pin is

an output if DE = 1.

B/Z

N/A

N/A

7

7

±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 I/O pin. For

parts without the cable invert function - or if INV is low - B/Z is the inverting

receiver input and inverting driver output. If INV is high, B/Z is the non-inverting

receiver input and the non-inverting driver output. Pin is an input if DE = 0; pin

is an output if DE = 1.

A

12

9

N/A

N/A

±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 non-inverting

receiver input.

B

11

8

N/A

N/A

±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 inverting

receiver input.

Y

9

6

N/A

N/A

±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 non-inverting

driver output.

Z

10

7

N/A

N/A

±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 inverting

driver output.

14

10

8

8

System power supply input (3V to 5.5V).

INV

N/A

N/A

N/A

2

Receiver and driver Cable Invert (polarity selection) input. When driven high

this pin swaps the polarity of the driver output and receiver input pins. If

unconnected (floating) or connected low, normal RS-485 polarity conventions

apply. Internally pulled low.

NC

1, 8, 13

N/A

N/A

N/A

No Internal Connection.