5

LTC1346A

1346afa

FU CTIO

TABLES

Transmitter and Receiver Configuration

S0

S1

S2

DX ON

RX ON

Description

00

0

—

1, 2, 3

All RX ON, All DX OFF

10

0—

—All OFF, Shutdown

01

0

1, 2, 3

1, 2

DCE Mode

11

0

1, 2, 3

—

DCE Mode, All RX OFF

00

1

1, 2

1, 2, 3

DTE Mode

10

1

1, 2

—

DTE Mode, All RX OFF

01

1

1, 2, 3

1, 2, 3

All ON

11

1

1, 2, 3

—

All DX ON, All RX OFF

Transmitter

INPUTS

OUTPUTS

CONFIGURATION S0 S1 S2

T Y1 AND Y2 Z1 AND Z2 Y3 Z3

All OFF

0

0

0

X

Z

Z

Z

Z

Shutdown

1

0

0

X

Z

Z

Z

Z

DCE or All ON

X

1

X

0

0

1

0

1

DCE or All ON

X

1

X

1

1

0

1

0

DTE

X

0

1

0

01

Z

Z

DTE

X

0

1

1

10

Z

Z

Receiver

INPUTS

OUTPUTS

CONFIGURATION

S0 S1 S2

A – B

R1 AND R2

R3

All Rx ON

0

0

0

≤ –0.2V

0

0

All Rx ON

0

0

0

≥ 0.2V

1

1

Shutdown

1

0

0

X

Z

Z

DCE

0

1

0

≤ –0.2V

0

Z

DCE

0

1

0

≥ 0.2V

1

Z

Disabled

1

1

0

X

Z

Z

DTE or All ON

0

X

1

≤ –0.2V

0

0

DTE or All ON

0

X

1

≥0.2V

1

1

Disabled

1

X

1

X

Z

Z

TEST CIRCUITS

1k

LTC1346A • F02

SW1

SW2

RECEIVER

OUTPUT

Figure 2. Receiver Output Enable and Disable Timing Test Load

15pF

S0

R

50Ω

125Ω

Y

Z

Z

Y

T

125Ω

50Ω

50Ω

LTC1346A • F01

50Ω

A

B

Figure 1. V.35 Transmitter/Receiver Test Circuit