SP504 View Datasheet(PDF) - Signal Processing Technologies

Part Name

Description

Manufacturer

SP504

WAN Multi-Mode Serial Transceiver

Signal Processing Technologies 

ADDITIONAL TRANSCEIVERS

WITH THE SP504

Serial ports usually can have two data signals

(SD, RD), three clock signals (TT, ST, RT), and

at least eight control signals (CS, RS, etc.). EIA-

RS-449 contains twenty six signal types for a

DB-37 connector. A DB-37 serial port design

may require thirteen drivers and fourteen re-

ceivers1. Although many applications do not

use all these signals, some applications may

need to support extra functions such as diagnos-

tics. The SP504 supports enough transceivers

for the primary channels of data, clock and

control signals. Configuring LL, RL and TM

would require two additional drivers and one

receiver if designing for a DTE (one driver and

two receivers for a DCE).

A programmable transceiver such as the SP332

is a convenient solution in a design that requires

extra single ended or differential drivers/receiv-

ers. As shown in Figure 28, the SP332 can be

configured to four different variations.

The SP332 in Figure 29 is configured for two

single-ended drivers and one diffferential re-

ceiver. For a DTE design, the two drivers are

used for LL and RL signals and the receiver is

used for the TM signal. This configuration was

selected because the two RS-232 drivers can be

SEL A

0

0

SEL B

0

1

LOOPBACK

1

1

SHUTDOWN

0

0

used for RS-423 by connecting a zener clamp-

ing diode to ground on the two driver outputs.

The diodes will limit the voltage swing on the

outputs so that the VOC = ±4V to ±6V adheres to

the RS-423 specification. The differential re-

ceiver can be easily configured to RS-423 by

grounding the non-inverting input. The receiver

will adhere to the RS-423 specifications.

CIRCUIT

MNEMONIC

CIRCUIT NAME

CIRCUIT

DIRECTION

CIRCUIT

TYPE

SG

SIGNAL GROUND

SC

SEND COMMON

--------------

TO DCE

COMMON

RC

RECEIVE COMMON

FROM DCE

IS

TERMINAL IN SERVICE

TO DCE

IC

INCOMING CALL

TR

TERMINAL READY

FROM DCE

TO DCE

CONTROL

DM

DATA MODE

FROM DCE

SD

SEND DATA

RD

RECEIVE DATA

TO DCE

FROM DCE

DATA

TT

TERMINAL TIMING

TO DCE

ST

SEND TIMING

FROM DCE TIMING

RT

RECEIVE TIMING

FROM DCE

RS

REQUEST TO SEND

TO DCE

CS

CLEAR TO SEND

FROM DCE

RR

RECEIVER READY

FROM DCE

SQ

SIGNAL QUALITY

NS

NEW SIGNAL

FROM DCE CONTROL

TO DCE

SF

SELECT FREQUENCY

TO DCE

SR

SIGNAL RATE SELECTOR

TO DCE

SI

SIGNAL RATE INDICATOR

FROM DCE

SSD

SECONDARY SEND DATA

TO DCE

DATA

SRD

SECONDARY RD

FROM DCE

SRS

SECONDARY RS

SCS

SECONDARY CS

TO DCE

FROM DCE CONTROL

SRR

SECONDARY RR

FROM DCE

LL

LOCAL LOOPBACK

TO DCE

RL

REMOTE LOOPBACK

TO DCE CONTROL

TM

TEST MODE

FROM DCE

SS

SB

SELECT STANDBY

STANDBY INDICATOR

TO DCE

FROM DCE

CONTROL

1 RS-449 Interchange Circuits Table

1

1

0

1

1

1

0

0

26 TI1

T1

27 TI2

T2

28 TI3

T3

1 TI4

T4

TX1 6

TX2 7

TX3 4

TX4 3

26 TI1

T1

27 TI2

T2

28 TI3 T3

TX1 6

TX2 7

26 TI1

T1

TX3 4

TX4 3

28 TI3 T3

1 TI4 T4

TX1 6

TX2 7

TX3 4

TX4 3

19 RX1

20 RX2

21 RX3

22 RX4

RI1 15

R1

RI2 16

R2

RI3 17

R3

RI4 18

R4

19 RX1

20 RX2

21 RX3

R1

RI1 15

19 RX1 R1

R2

RI2 16

RI3 17

21 RX3

R3

R3

RI4 18

22 RX4 R4

RI1 15

RI2 16

RI3 17

RI4 18

26 TI1 T1

TX1 6

TX2 7

28 TI3 T3

TX3 4

TX4 3

19 RX1 R1

RI1 15

RI2 16

21 RX3 R3

RI3 17

RI4 18

Figure 28. Mode selection for the SP332

Rev: A Date:1/27/04

SP504 Multi–Mode Serial Transceivers

28

© Copyright 2004 Sipex Corporation

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