1318 Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

производитель

1318

Single 5V RS232/RS422/AppleTalk® DCE Transceiver

Linear Technology 

TYPICAL PERFORMANCE CHARACTERISTICS

RS422 Receiver Differential

Threshold vs Temperature

100

VCC = 5V

90

80

INPUT HIGH

70

60

50

INPUT LOW

40

30

20

0 10

20 30 40 50 60 70

TEMPERATURE (°C)

1318 G10

RS232 Receiver Input Threshold

vs Temperature

2.4

VCC = 5V

2.2

INPUT HIGH (RXDO/RXO2)

2.0

1.8

INPUT HIGH (RXO1)

1.6

1.4

INPUT LOW (RXO1)

1.2 INPUT LOW (RXDO/RXO2)

1.0

0.8

0 10

20 30 40 50

TEMPERATURE (°C)

60 70

1318 G11

LTC1318

TTL Output Short-Circuit Current

vs Temperature

24

VCC = 5V

22

RXO1

20

18

RXDO/RXO2

16

14

12

10

0 10 20 30 40 50 60 70

TEMPERATURE (°C)

1318 G12

PIN FUNCTIONS

V+ (Pin 1): Charge Pump Positive Output. This pin re-

quires a 0.1µF capacitor to ground. Under normal opera-

tion this pin maintains a voltage of about 8.8V above

ground. An external load can be connected between this

pin and ground or V–.

C1+, C1– (Pins 2, 3): C1 Inputs. Connect a 0.1µF capacitor

between C1+ and C1–.

RXI1 (Pin 4): First RS232 Single-Ended Receiver Input.

This is an inverting receiver.

TXO1, TXO2 (Pins 5,6): RS232 Single-Ended Driver Out-

puts.

VCC (Pin 7): Positive Supply Input. Apply 4.75V ≤ VCC ≤

5.25V to this pin. A 0.1µF bypass capacitor is required.

RXD+ (Pin 8): When RXMODE (pin 15) is low, this pin acts

as the differential RS422 receiver positive input. When

RXMODE is high, this pin is disabled.

RXD–/RXI2 (Pin 9): When RXMODE (pin 15) is low, this

pin acts as the differential RS422 receiver negative input.

When RXMODE is high, this pin acts as the second RS232

receiver input. The receiver is inverting in RS232 mode.

TXD+ (Pin 10): Differential RS422 Driver Noninverting

Output.

TXD– (Pin 11): Differential RS422 Driver Inverting Output.

NC (Pins 12,13): No Internal Connection.

GND (Pins 14, 18): Power Supply Ground. Connect both

pins to each other and to the ground.

RXMODE (Pin 15): This pin controls the state of the

differential/single-ended receiver. When RXMODE is low,

the receiver is in differential mode and will receive RS422

compatible signals at RXD+ and RXD–/RXI2 (pins 8

and 9). When RXMODE goes high, the receiver enters

single-ended mode and will receive RS232 compatible

signals at RXD–/RXI2. RXD+ is disabled in single-ended

mode. Both modes use the RXDO/RXO2 pin (pin 17) as

their output.

TXD (Pin 16): Differential RS422 Driver Input (TTL Com-

patible).

RXDO/RXO2 (Pin 17): This is the output of the configurable

differential/single-ended receiver.

TXI1, TXI2 (Pins 20, 19): RS232 Driver Inputs (TTL

Compatible). Both are inverting inputs.

RXO1 (Pin 21): First RS232 Receiver Outputs (TTL com-

patible).

5

Share Link: