SP3488 Datasheet, PDF (5/9 Pages) Sipex Corporation – +3.3V Low Power Quad RS-485/RS-422 Line Receivers

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 15KΩ (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_CC = +3.3V±5%; typicals at 25°C; T_AMB = 25°C unless otherwise noted.
PARAMETER
MIN. TYP. MAX.
PROPAGATION DELAY
Receiver Input to Output
Low to HIGH (tPLH)
High to LOW (tPH_L)
Differential Receiver Skew (t_SKD)
Receiver Rise Time (t_R)
SP3488
SP3489
Receiver Fall Time (t_F)
SP3488
SP3489
RECEIVER ENABLE
To Output HIGH
75
115
80
115
4
7
15
7
15
6
15
6
15
46
100
To Output LOW
46
100
RECEIVER DISABLE
From Output LOW
From Output HIGH
46
100
46
100
UNIT
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
CONDITIONS
C_L = 15pF; Figure 1, 3
10% to 90%
90% to 10%
C_L = 15pF; Figures 2 and 4
(S2 closed)
CL = 15pF; Figures 2 and 4
(S1 closed)
CL = 15pF; Figures 2 and 4
(S1 closed)
CL = 15pF; Figures 2 and 4
(S2 closed)
10/16/02
SP3488/3489 Low Power Quad RS-485/422 Line Receivers
5
© Copyright 2002 Sipex Corporation