5

10/16/02

SP3488/3489 Low Power Quad RS-485/422 Line Receivers

© Copyright 2002 Sipex Corporation

PARAMETER

MIN.

TYP.

MAX.

UNIT

CONDITIONS

PROPAGATION DELAY

Receiver Input to Output

C

Low to HIGH (tPLH)

75

115

ns

High to LOW (tPH

115

ns

Differential Receiver Skew (t

ns

Receiver Rise Time (t

10% to 90%

SP3488

7

15

ns

SP3489

7

15

ns

Receiver Fall Time (t

90% to 10%

SP3488

6

15

ns

SP3489

6

15

ns

RECEIVER ENABLE

To Output HIGH

46

100

ns

C

(S2 closed)

To Output LOW

46

100

ns

CL = 15pF;

Figures 2 and 4

(S1 closed)

RECEIVER DISABLE

From Output LOW

46

100

ns

CL = 15pF;

Figures 2 and 4

(S1 closed)

From Output HIGH

46

100

ns

CL = 15pF;

Figures 2 and 4

(S2 closed)

cabling can be as long as 4,000 feet, RS-485

transceivers are equipped with a wide (-7V to

+12V) common mode range to accomodate

ground potential differences. Because the

RS-485 protocol is a differential interface, data

is virtually immune to noise in the transmission

line.

Receiver...

The SP3488 and the SP3489 receivers have

differential inputs with an input sensitivity

as low as +100mV. Input impedance of the

receivers is typically 15K

Ω (12KΩ minimum).

A wide common mode range of -7V to +12V

allows for large ground potential differences

between systems.

The SP3488 features active HIGH and active

LOW common receiver enable controls. Refer

to SP3488 Truth Table in Table 1. The SP3489

provides independent, active high receiver

enable controls for each pair of receivers. Refer

to SP3489 Truth Table in Table 2. Both devices

feature tri-state outputs and a -7V to +12V

common-mode input range permitting a +7V

ground difference between devices on the

communication bus. The SP3488 and the SP3489

are equipped with a fail-safe feature which forces

a logic HIGH at the receiver output when the

input is left floating. The SP3488 and SP3489

receivers meet the electrical specifications of

RS-485 and RS-422 serial protocol data rates up

to 10Mbps under load.

AC PARAMETERS

V