Transceivers with ±15kV ESD Protection

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13

Pin Description

PIN

NAME

ISOLATION SIDE

FUNCTION

Logic

capacitors.

2

ST1

Logic

Transformer-Driver Phase 1 Power Output. Connect ST1 to isolation-transformer

primary to send power to isolation side of barrier.

3

ST2

Logic

Transformer-Driver Phase 2 Power Output. Connect ST2 to isolation-transformer

primary to send power to isolation side of barrier.

4

GND1

Logic

Logic-Side Ground. For isolated operation do not connect to GND2.

5–10,

19–24

——

Removed from Package

11

GND2

Isolated

Isolation-Side Ground. For isolated operation do not connect to GND1.

12

Z

Isolated

RS-485/RS-422 Inverting Driver Output. Output floats when DE is low or in a barrier fault

event. (See the Detailed Description section for more information.)

13

Y

Isolated

RS-485/RS-422 Noninverting Driver Output. Output floats when DE is low or in a barrier

fault event. (See the Detailed Description section for more information.)

14

Isolated

15

B

Isolated

RS-485/RS-422 Differential-Receiver Inverting Input

16

A

Isolated

RS-485/RS-422 Differential-Receiver Noninverting Input

17

RO2

Isolated

Isolated-Side Receiver Output. RO2 is always enabled. RO2 goes high if A - B > -10mV.

RO2 goes low if A - B < -200mV. Fail-safe circuitry causes RO2 to go high when A and B

float or are shorted.

18

SLO

Isolated

Driver Slew-Rate Control Logic Input. Connect SLO to GND2 for data rates up to

25

DI

Logic

Driver Input. Pull DI low (high) to force driver output Y low (high) and driver output Z

high (low).

26

DE

Logic

Driver-Enable Input. The driver outputs are enabled and follow the driver input (DI)

when DE is high. When DE is floated, the driver is disabled. DE does not affect whether

the receiver is on or off.

27

RE

Logic

Receiver-Output Enable and Fault Current Output. The receiver output (RO1) is

enabled and follows the differential-receiver inputs, A and B, when RE is low, otherwise

RO1 floats. RE does not affect RO2 and does not disable the driver. The asserted fault

output is a pullup current, otherwise RE shows a pulldown current.

28

RO1

Logic

Receiver Output. RO1 is enabled when RE is low. RO1 goes high if A - B > -10mV. RO1

goes low if A - B < -200mV. Fail-safe circuitry causes RO1 to go high when A and B

float or are shorted.