SP502 View Datasheet(PDF) - Signal Processing Technologies

Part Name

Description

Manufacturer

SP502

Multi–Mode Serial Transceiver

Signal Processing Technologies 

VCC = +5V

+

C1 –

–5V

+5V

+

C2 –

–5V

C4

+ – VDD Storage Capacitor

– + VSS Storage Capacitor

C3

Figure 4. Charge Pump Phase 3.

VCC = +5V

+

C1 –

+10V

+

C2 –

C4

+ – VDD Storage Capacitor

– + VSS Storage Capacitor

C3

Figure 5. Charge Pump Phase 4.

power supplies should provide a power

supply sequence of: +l0V, then +5V, followed

by –l0V.

Drivers

The SP502 has six (6) drivers which can be

programmed in six different modes of opera-

tion. One of the drivers for the SP502 is inter-

nally connected to an internal receiver input to

make up a half-duplex configuration. As shown

in the Mode Diagrams, the driver input of the

half-duplex channel is shared with an adjacent

driver such that when one is active the other is

disabled.

Control for the mode selection is done via a

four–bit control word. The SP502 does not have

a latch; the control word must be externally

latched either high or low to write the appropri-

ate code into the SP502. The drivers are pre-

arranged such that for each mode of operation

the relative position and functionality of the

drivers are set up to accommodate the selected

interface mode. As the mode of the drivers is

changed, the electrical characteristics will change

to support the requirements of clock, data, and

control line signal levels. Table 1 shows a sum-

mary of the electrical characteristics of the driv-

ers in the different interface modes. Unused

driver inputs can be left floating; however, to

ensure a desired state with no input signal, pull–

up resistors to +5V or pull–down resistors to

ground are suggested. Since the driver inputs

are both TTL or CMOS compatible, any value

resistor less than 100kΩ will suffice.

There are three basic types of driver circuits —

RS-232, RS-423, and RS-485. The RS-232 driv-

ers output a minimum of ±5V level single–ended

signals (with 3kΩ and 2500pF loading), and

Pin Label

Mode:

RS-232

V.35

TDEC3–TDEC0

SD(a)

0000

tri–state

0010

RS-232

1110

V.35–

SD(b)

tri–state

tri–state

V.35+

TR(a)

tri–state

RS-232

RS-232

TR(b)

tri–state

tri–state

tri–state

RS(a)

tri–state

RS-232

RS-232

RS(b)

tri–state

tri–state

tri–state

RL(a)

tri–state

RS-232

RS-232

RL(b)

tri–state

tri–state

tri–state

LL(a)

tri–state

RS-232

RS-232

LL(b)

tri–state

tri–state

tri–state

ST(a)

tri–state

RS-232

V.35–

ST(b)

tri–state

tri–state

V.35+

TT(a)

tri–state

RS-232

V.35–

TT(b)

tri–state

tri–state

V.35+

*The ST and TT driver outputs cannot be enabled simultaneously.

Table 1. SP502 Drivers

RS-422

0100

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-485

0101

RS-485–

RS-485+

RS-485–

RS-485+

RS-485–

RS-485+

RS-485–

RS-485+

RS-485–

RS-485+

RS-485–

RS-485+

RS-485–

RS-485+

RS-449

1100

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-423

tri–state

RS-423

tri–state

RS-422–

RS-422+

RS-422–

RS-422+

EIA-530

1101

RS-422–

RS-422+

RS-422–

RS-422+

RS-422–

RS-422+

RS-423

tri–state

RS-423

tri–state

RS-422–

RS-422+

RS-422–

RS-422+

Rev. 7/21/03

SP502 Multi-Mode Serial Transceiver

10

© Copyright 2003 Sipex Corporation

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