LTC2846 datasheet(13/24 Pages) LINER

13 / 24 page

LTC2846

sn2846 2846fs

Figure 18. Single Port DCE V.35 Mode Selection in the Cable

Figure 20. V.10 Receiver Input Impedance

Figure 19. Typical V.10 Interface

APPLICATIO S I FOR ATIO

selected. Switching the terminations with FETs is difficult

because the FETs must remain off when the signal voltage

is beyond the supply voltage. Alternatively, custom cables

may contain termination in the cable head or route signals

to various terminations on the board.

The LTC2846/LTC2844 chip set solves the cable termina-

tion switching problem by automatically providing the

appropriate termination and switching on-chip for the

V.10 (RS423), V.11 (RS422), V.28 (RS232) and V.35

electrical protocols.

V.10 (RS423) Interface

All V.10 drivers and receivers necessary for the RS449,

EIA530, EIA530-A, V.36 and X.21 protocols are imple-

mented on the LTC2844 or LTC2845.

A typical V.10 unbalanced interface is shown in Figure 19.

A V.10 single-ended generator with output A and ground

C is connected to a differential receiver with input A' con-

nected to A, and ground C' connected via the signal return

to ground C. Usually, no cable termination is required for

V.10 interfaces, but the receiver inputs must be compliant

with the impedance curve shown in Figure 20.

The V.10 receiver configuration in the LTC2844 and

LTC2845 is shown in Figure 21. In V.10 mode, switch S3

inside the LTC2844 and LTC2845 is turned off. The

noninverting input is disconnected inside the LTC2844

CABLE

2846 F18

LTC2846

LTC2844

CONNECTOR

(DATA)

DCE/DTE

(DATA)

GENERATOR

BALANCED

INTERCONNECTING

CABLE

LOAD

CABLE

TERMINATION

RECEIVER

2846 F19

–10V

–3.25mA

3.25mA

–3V

10V

2846 F20

LTC2846 Datasheet(PDF) 13 Page - Linear Technology

LTC2846 Datasheet(HTML) 13 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Datasheet Download

Link URL