®
SP3488 and SP3489
+3.3V Low Power Quad
RS-485/RS-422 Line Receivers
■
RS-485 or RS-422 Quad Differential
Line Receivers
■
Operates from a single +3.3V supply
■
Interoperable with +5.0V logic
■
Tri-state Output Control
■
-7V to +12V Common-Mode Input
Voltage Range
■
Common Driver Enable Control
(SP3488)
■
Independent Driver Enable Controls
for each pair of Drivers (SP3489)
■
Compatibility with LTC488
and SN75173 (SP3488)
■
Compatibility with LTC489
and SN75175 (SP3489)
DESCRIPTION…
The
SP3488
and the
SP3489
are +3.3V low power quad line receivers that meet the
specifications of the RS-485 and RS-422 serial protocols. These devices are pin-to-pin
compatible with Sipex's SP488 and SP489 devices as well as popular industry standards.
The
SP3488
and
SP3489
feature Sipex's BiCMOS process allowing low power operation
without sacrificing performance. The
SP3488
and
SP3489
meet the electrical specifications
of RS-485 and RS-422 serial protocols up to 10Mbps under load. The
SP3488
features a
common receiver enable control. The
SP3489
provides independent receiver enable
controls for each pair of receivers. Both devices feature tri-state outputs and a -7V to +12V
common-mode input range. The receivers have a fail-safe feature which forces a logic "1"
output when receiver inputs are left floating.
RI
1
B
RI
1
A
RO
1
EN
RO
2
RI
2
A
RI
2
B
GND
1
2
3
4
5
6
7
8
SP3488
1
4
16
15
14
13
12
V
CC
RI
4
B
RI
4
A
RO
4
EN
RO
3
RI
3
A
RI
3
B
RI
1
B
RI
1
A
RO
1
EN
1
/EN
2
RO
2
RI
2
A
RI
2
B
GND
1
2
3
4
5
6
7
8
SP3489
1
4
16
15
14
13
12
V
CC
RI
4
B
RI
4
A
RO
4
EN
3
/EN
4
RO
3
RI
3
A
RI
3
B
2
3
11
10
9
2
3
11
10
9
10/16/02
SP3488/3489 Low Power Quad RS-485/422 Line Receivers
© Copyright 2002 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of the device
at these or any other above those indicated in the operation
sections of the specifications below is not implied. Exposure to
absolute maximum rating conditions for extended periods of time
may affect reliability.
V
CC
......................................................................................... +6.0V
Input Voltages
Logic ...................................................................... –0.3V to +6.0V
Receiver ...............................................................................
±14V
Receiver Output Voltage .......................................... –0.3V to +6.0V
Input Currents
Logic ..................................................................................
±25mA
Storage Temperature ............................................ –65°C to +150°C
Power Dissipation
Plastic DIP ........................................................................ 375mW
(derate 7mW/°C above +70°C)
Small Outline .................................................................... 375mW
(derate 7mW/°C above +70°C)
Lead Temperature (soldering, 10 sec) ................................... 300°C
SPECIFICATIONS
V
CC
= +3.3V±5%; typicals at 25°C; T
MIN
≤
T
A
≤
T
MAX
unless otherwise noted.
PARAMETER
DC CHARACTERISTICS
Digital Inputs
Voltage
V
IL
V
IH
Input Current
RECEIVER INPUTS
Input Resistance
Differential Input Threshold
Input Current (A, B)
MIN.
TYP.
MAX.
UNIT
CONDITIONS
EN, EN, EN
1
/EN
2
, EN
3
/EN
4
0.8
2.0
±2
Volts
Volts
µA
0V
≤
V
IN
≤
V
CC
12
-0.2
+0.2
+1.0
-0.8
kΩ
Volts
mA
mA
Mbps
Maximum Data Rate
10
RECEIVER OUTPUTS
Output Voltage
V
OH
V
CC
-0.4
V
OL
0.4
High Impedance Output Current
±1
POWER REQUIREMENTS
Supply Current
2.2
5
ENVIRONMENTAL AND MECHANICAL
Operating Temperature
–C
0
+70
–E
-40
+85
Storage Temperature
-65
+150
Package
–_P
16–pin Plastic DIP
–_T
16–pin SOIC
-7V
≤
V
CM
≤
12V
-7V
≤
V
CM
≤
12V
V
CC
= 0V or 3.3V; I
IN2
V
IN
= +12V
V
IN
= –7V
V
V
µA
mA
I
O
= -1.5mA; V
ID
= +0.2V
I
O
= +2.5mA; V
ID
= -0.2V
V
CC
= maximum; 0.4V
≤
V
O
≤
V
CC
No load
°C
°C
°C
10/16/02
SP3488/3489 Low Power Quad RS-485/422 Line Receivers
© Copyright 2002 Sipex Corporation
2
15pF EN
A
S
1
RCVR
54Ω
RCVR
ROn
C
L
15pF
EN
1/4 SP3488
1kΩ
V
CC
DI
DRIVER
B
C
L
1kΩ
S
2
1/4 SP3486
Figure 1. Timing Test Circuit
Figure 2. Enable/Disable Timing Test Circuit
SP3488 PINOUT
Pin 1 — RI
1
B — Receiver 1 input B.
Pin 2 — RI
1
A
—
Receiver 1 input A.
Pin 3 — RO
1
— Receiver 1 Output — If Re-
ceiver 1 output is enabled, if RI
1
A > RI
1
B by
200mV, Receiver output is high. If Receiver 1
output is enabled, and if RI
1
A < RI
1
B by 200mV,
Receiver 1 output is low.
Pin 4 — EN — Receiver Output Enable. Please
refer to SP3488
Truth Table (1).
Pin 5 — RO
2
— Receiver 2 Output — If Re-
ceiver 2 output is enabled, if RI
2
A > RI
2
B by
200mV, Receiver 2 output is high. If Receiver 2
output is enabled, and if RI
2
A < RI
2
B by
200mV, Receiver 2 output is low.
PINOUT
Pin 6 — RI
2
A — Receiver 2 input A.
Pin 7 — RI
2
B — Receiver 2 input B.
Pin 8 — GND — Digital Ground.
Pin 9 — RI
3
B — Receiver 3 input B.
Pin 10 — RI
3
A — Receiver 3 input A.
Pin 11 — RO
3
— Receiver 3 Output — If
Receiver 3 output is enabled, if RI
3
A > RI
3
B by
200mV, Receiver 3 output is high. If Receiver 3
output is enabled, and if RI
3
A < RI
3
B by
200mV, Receiver 3 output is low.
Pin 12 — EN — Receiver Output Enable. Please
refer to SP3488 Truth Table (1).
RI
1
B
RI
1
A
RO
1
EN
RO
2
RI
2
A
RI
2
B
GND
1
2
3
4
5
6
7
8
SP3488
1
4
16
15
14
13
12
V
CC
RI
4
B
RI
4
A
RO
4
EN
RO
3
RI
3
A
RI
3
B
RI
1
B
RI
1
A
RO
1
EN
1
/EN
2
RO
2
RI
2
A
RI
2
B
GND
1
2
3
4
5
6
7
8
SP3489
1
4
16
15
14
13
12
V
CC
RI
4
B
RI
4
A
RO
4
EN
3
/EN
4
RO
3
RI
3
A
RI
3
B
2
3
11
10
9
2
3
11
10
9
10/16/02
SP3488/3489 Low Power Quad RS-485/422 Line Receivers
© Copyright 2002 Sipex Corporation
3
Pin 13 — RO
4
— Receiver 4 Output — If
Receiver 4 output is enabled, if RI
4
A > RI
4
B by
200mV, Receiver 4 output is high. If Receiver 4
output is enabled, and if RI
4
A < RI
4
B by
200mV, Receiver 4 output is low.
Pin 14 — RI
4
A — Receiver 4 input A.
Pin 15 — RI
4
B — Receiver 4 input B.
Pin 16 — V
CC
— Positive Supply +3.00V < V
CC
< +3.60V
SP3489 PINOUT
Pin 1 — RI
1
B — Receiver 1 input B.
Pin 2 — RI
1
A — Receiver 1 input A.
Pin 3 — RO
1
— Receiver 1 Output — If
Receiver 1 output is enabled, if RI
1A
> RI
1
B by
200mV, Receiver output is high. If Receiver 1
output is enabled, and if RI
1
A < RI
1
B by 200mV,
Receiver 1 output is low.
Pin 4 — EN1/EN2 — Receiver 1 and 2 Output
Enable. Please refer to SP3489
Truth Table (2).
Pin 5 — RO
2
— Receiver 2 Output — If
Receiver 2 output is enabled, if RI
2
A > RI
2
B by
200mV, Receiver 2 output is high. If Receiver 2
output is enabled, and if RI
2
A < RI
2
B by
200mV, Receiver 2 output is low.
Pin 6 — RI
2
A — Receiver 2 input A.
Pin 7 — RI
2
B — Receiver 2 input B.
Pin 8 — GND — Digital Ground.
Pin 9 — RI
3
B — Receiver 3 input B.
Pin 10 — RI
3
A — Receiver 3 input A.
Pin 11 — RO
3
— Receiver 3 Output — If
Receiver 3 output is enabled, if RI
3
A > RI
3
B by
200mV, Receiver 3 output is high. If Receiver 3
output is enabled, and if RI
3
A < RI
3
B by
200mV, Receiver 3 output is low.
Pin 12 — EN3/EN4 — Receiver 3 and 4 Output
Enable. Please refer to SP3489 Truth Table (2).
Pin 13 — RO
4
— Receiver 4 Output — If
Receiver 4 output is enabled, if RI
4
A > RI
4
B by
200mV, Receiver 4 output is high. If Receiver 4
output is enabled, and if RI
4
A < RI
4
B by
200mV, Receiver 4 output is low.
Pin 14 — RI
4
A — Receiver 4 input A.
Pin 15 — RI
4
B — Receiver 4 input B.
Pin 16 — V
CC
— Positive Supply +3.00V < V
CC
< +3.60V
FEATURES...
The
SP3488
and the
SP3489
are +3.3V low
power quad line receivers that meet the
specifications of the RS-485 and RS-422 serial
protocols. These devices are pin-to-pin
compatible with Sipex's SP488 and SP489
devices as well as popular industry standards.
The
SP3488
and
SP3489
devices feature
Sipex's BiCMOS process allowing low power
operation without sacrificing performance.
The RS-485 standard is ideal for multi-drop
applications or for long distance interfaces.
RS-485 allows up to 32 drivers and 32 receivers
to be connected to a data bus, making it an ideal
choice for multi-drop applications. Since the
DIFFERENTIAL
A–B
V
ID
≥
0.2V
–0.2V < V
ID
< +0.2V
V
ID
≤
0.2V
X
ENABLES
EN
1
/EN
2
or EN
3
/EN
4
H
H
H
L
OUTPUT
RO
H
X
L
Hi–Z
DIFFERENTIAL
A–B
V
ID
≥
0.2V
–0.2V < V
ID
< +0.2V
V
ID
≤
0.2V
X
EN
H
X
H
X
H
X
L
ENABLES
EN
X
L
X
L
X
L
H
OUTPUT
RO
H
H
X
X
L
L
Hi–Z
Table 1. SP3488 Truth Table
10/16/02
Table 2. SP3489 Truth Table
© Copyright 2002 Sipex Corporation
SP3488/3489 Low Power Quad RS-485/422 Line Receivers
4
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.
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
To Output LOW
RECEIVER DISABLE
From Output LOW
From Output HIGH
TYP.
MAX.
UNIT
CONDITIONS
C
L
= 15pF;
Figure 1, 3
75
80
4
7
7
6
6
46
46
115
115
15
15
15
15
100
100
ns
ns
ns
ns
ns
10% to 90%
90% to 10%
ns
ns
ns
ns
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)
46
46
100
100
ns
ns
10/16/02
SP3488/3489 Low Power Quad RS-485/422 Line Receivers
© Copyright 2002 Sipex Corporation
5
京公网安备 11010802033920号
EEWORLD
