5

LTC1338

PI FU CTIO S

DRIVER IN: RS232 Driver Input Pins. Inputs are TTL/

CMOS compatible. Inputs should not be allowed to float.

DRIVER OUT: Driver Outputs at RS232 Voltage Levels.

Outputs are in a high impedance state when in SHUT-

outputs are protected against ESD to

±10kV for human

body model discharges.

RX IN: Receiver Inputs. These pins can be forced to

±25V

without damage. The receiver inputs are protected against

ESD to

±10kV for human body model discharges. Each

receiver provides 0.4V of hysteresis for noise immunity.

RX OUT: Receiver Outputs with TTL/CMOS Voltage Lev-

els. Outputs are in a high impedance state when in SHUT-

DOWN or RECEIVER DISABLE mode to allow data line

sharing.

Table 1. Functional Description

MODE

RX ENABLE

DR ENABLE

DRIVERS

RECEIVERS

SHUTDOWN

0

0

All driver outputs are

All receiver outputs are

0.2

high impedance.

high impedance.

Receiver Disable

0

1

All drivers alive.

All receiver outputs are

500

high impedance.

RECEIVER ALIVE

1

0

All driver outputs are

All receivers alive.

50

high impedance.

Normal

1

1

All drivers alive.

All receivers alive.

500

TI E WAVEFOR

S

G

WITCHI

S

Figure 1. Driver Propagation Delay Timing

Figure 2. Receiver Propagation Delay Timing

1.4V

0V

0V

0V

DRIVER

INPUT

DRIVER

OUTPUT

1.4V

LTC1338 • F01

0.8V

0V

2.4V

RX

INPUT

RX

OUTPUT

1.3V

1.7V

LTC1338 • F02

0V