®
SP481E/SP485E
Enhanced Low Power Half-Duplex
RS-485 Transceivers
■
+5V Only
■
Low Power BiCMOS
■
Driver/Receiver Enable for Multi-Drop
configurations
■
Low Power Shutdown Mode
(SP481E)
■
Enhanced ESD Specifications:
+15KV Human Body Model
+15KV IEC1000-4-2 Air Discharge
+8KV IEC1000-4-2 Contact Discharge
DESCRIPTION
The
SP481E
and the
SP485E
are a family of half-duplex transceivers that meet the
specifications of RS-485 and RS-422 serial protocols with enhanced ESD performance. The
ESD tolerance has been improved on these devices to over +15KV for both Human Body
Model and IEC1000-4-2 Air Discharge Method. These devices are pin-to-pin compatible with
Sipex's SP481 and SP485 devices as well as popular industry standards. As with the original
versions, the
SP481E
and the
SP485E
feature Sipex's BiCMOS design allowing low power
operation without sacrificing performance. The
SP481E
and
SP485E
meet the requirements
of the RS-485 and RS-422 protocols up to 10Mbps under load. The
SP481E
is equipped with
a low power Shutdown mode.
RO 1
RE 2
DE 3
DI 4
R
8 Vcc
7B
6A
D
SP481E and SP485E
5 GND
Rev. 5/16/03
SP481E Low Power Half-Duplex RS485 Transceivers
© Copyright 2003 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of the device at
these ratings 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
............................................................................................................+7V
Input Voltages
Logic........................................................-0.3V to (V
CC
+0.5V)
Drivers..................................................-0.3V to (V
CC
+0.5V)
Receivers.................................................................
±15V
Output Voltages
Logic........................................................-0.3V to (V
CC
+0.5V)
Drivers......................................................................
±15V
Receivers............................................-0.3V to (V
CC
+0.5V)
Storage Temperature.......................................................-65˚C to +150˚C
Power Dissipation per Package
8-pin NSOIC (derate 6.60mW/
o
C above +70
o
C)...........................550mW
8-pin PDIP (derate 11.8mW/
o
C above +70
o
C)............................1000mW
SPECIFICATIONS
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP481E/SP485E DRIVER
DC Characteristics
Differential Output Voltage
Differential Output Voltage
Differential Output Voltage
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
Driver Common-Mode
Output Voltage
Input High Voltage
Input Low Voltage
Input Current
Driver Short-Circuit Current
V
OUT
= HIGH
V
OUT
= LOW
SP481E/SP485E DRIVER
AC Characteristics
Maximum Data Rate
Driver Input to Output
Driver Input to Output
(SP485EMN ONLY)
Driver Input to Output
Driver Input to Output
(SP485EMN ONLY)
Driver Skew
Driver Rise or Fall Time
Driver Enable to Output High
closed
Driver Enable to Output Low
closed
Driver Disable Time from Low
closed
Driver Disable Time from High
closed
MIN.
TYP.
MAX.
UNITS
CONDITIONS
GND
2
1.5
V
CC
V
CC
V
CC
0.2
3
Volts
Volts
Volts
Unloaded; R =
∞
;
see Figure 1
with load; R = 50Ω; (RS-422);
see Figure 1
with load; R = 27Ω; (RS-485);see
Figure 1
Volts
Volts
Volts
Volts
µA
mA
mA
R = 27Ω or R = 50Ω;
see Figure 1
R = 27Ω or R = 50Ω;
see Figure 1
Applies to DE, DI, RE
Applies to DE, DI, RE
Applies to DE, DI, RE
-7V
≤
V
O
≤
+12V
-7V
≤
V
O
≤
+12V
2.0
0.8
±10
±250
±250
10
20
20
30
30
60
80
Mbps
ns
ns
RE = 5V, DE = 5V; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
t
PLH
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see Figures 3 and 5
t
PLH
; R
DIFF
= 54Ω, C
LI
= C
L2
= 100pF;
See Figures 3 and 5
t
PHL
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see Figures 3 and 5
t
PHL
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see Figures 3 and 5
see Figures 3 and 5,
t
SKEW
= | t
DPLH
- t
DPHL
|
From 10% to 90%; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF;
see
Figures 3 &
6
C
L
= 100pF;
see Figures 4 & 6;
S
2
C
L
= 100pF;
see Figures 4 & 6;
S
1
C
L
= 100pF;
see Figures 4 & 6;
S
1
C
L
= 100pF;
see Figures 4 & 6;
S
2
20
20
30
30
5
60
80
10
40
70
70
70
70
ns
ns
ns
ns
ns
ns
ns
ns
3
15
40
40
40
40
Rev. 5/16/03
SP481E Low Power Half-Duplex RS485 Transceivers
© Copyright 2003 Sipex Corporation
2
SPECIFICATIONS
(continued)
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
MIN.
SP481E/SP485E RECEIVER
DC Characteristics
Differential Input Threshold
-0.2
Differential Input Threshold
-0.4
(SP485EMN ONLY)
Input Hysteresis
Output Voltage High
3.5
Output Voltage Low
Three-State (High Impedance)
Output Current
Input Resistance
12
Input Current (A, B); V
IN
= 12V
Input Current (A, B); V
IN
= -7V
Short-Circuit Current
7
SP481E/SP485E RECEIVER
AC Characteristics
Maximum Data Rate
10
Receiver Input to Output
20
Receiver Input to Output
Diff. Receiver Skew It
PLH
-t
PHL
I
Receiver Enable to
Output Low
Receiver Enable to
Output High
Receiver Disable from Low
Receiver Disable from High
SP481E
Shutdown Timing
Time to Shutdown
50
Driver Enable from Shutdown
to Output High
Driver Enable from Shutdown
to Output Low
Receiver Enable from
Shutdown to Output High
Receiver Enable from
Shutdown to Output Low
POWER REQUIREMENTS
Supply Voltage
+4.75
Supply Current
SP481E/485E
No Load
SP481E
Shutdown Mode
ENVIRONMENTAL AND MECHANICAL
Operating Temperature
Commercial (_C_)
0
Industrial (_E_)
-40
(_M_)
-40
Storage Temperature
-65
Package
Plastic DIP (_P)
NSOIC (_N)
Rev. 5/16/03
TYP.
MAX.
UNITS
CONDITIONS
+0.2
+0.4
20
0.4
±1
15
+1.0
-0.8
95
Volts
Volts
mV
Volts
Volts
µA
kΩ
mA
mA
mA
-7V
≤
V
CM
≤
+12V
-7V
≤
V
CM
≤
+12V
V
CM
= 0V
I
O
= -4mA, V
ID
= +200mV
I
O
= +4mA, V
ID
= -200mV
0.4V
≤
V
O
≤
2.4V; RE = 5V
-7V
≤
V
CM
≤
+12V
DE = 0V, V
CC
= 0V or 5.25V, V
IN
= 12V
DE = 0V, V
CC
= 0V or 5.25V, V
IN
= -7V
0V
≤
V
O
≤
V
CC
RE = 0V, DE = 0V
t
PLH
; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF;
Figures 3 & 7
t
PHL
; R
DIFF
= 54Ω,
C
L1
= C
L2 =
100pF;
Figures 3 & 7
R
DIFF
= 54Ω; C
L1
= C
L2
= 100pF;
Figures 3 & 7
C
RL
= 15pF;
Figures 2 & 8;
S
1
closed
C
RL
= 15pF;
Figures 2 & 8;
S
2
closed
C
RL
= 15pF;
Figures 2 & 8;
S
1
closed
C
RL
= 15pF;
Figures 2 & 8;
S
2
closed
45
45
13
100
100
Mbps
ns
ns
ns
20
45
45
45
45
70
70
70
70
ns
ns
ns
ns
200
40
40
300
300
600
100
100
1000
1000
+5.25
ns
ns
ns
ns
ns
Volts
RE = 5V, DE = 0V
C
L
= 100pF;
See Figures 4 & 6;
S
2
closed
C
L
= 100pF;
See Figures 4 & 6;
S
1
closed
C
L
= 15pF;
See Figures 2 & 8;
S
2
closed
C
L
= 15pF;
See Figures 2 & 8;
S
1
closed
900
600
10
µA
µA
µA
RE, DI = 0V or V
CC
; DE = V
CC
RE = 0V, DI = 0V or 5V; DE = 0V
DE = 0V, RE=V
CC
+70
+85
+125
+150
°C
°C
°C
°C
SP481E Low Power Half-Duplex RS485 Transceivers
© Copyright 2003 Sipex Corporation
3
PIN FUNCTION
RO 1
R
8
V
CC
Pin 1 – RO – Receiver Output.
Pin 2 – RE – Receiver Output Enable Active LOW.
RE 2
7
B
Pin 3 – DE – Driver Output Enable Active HIGH.
Pin 4 – DI – Driver Input.
Pin 5 – GND – Ground Connection.
DE 3
6
A
D
DI 4
SP485
Top View
5
GND
Pin 6 – A – Driver Output/Receiver Input
Non-inverting.
Pin 7 – B – Driver Output/Receiver Input Inverting.
Pin 8 – Vcc – Positive Supply 4.75V<Vcc< 5.25V.
SP481E and SP485E
Pinout (Top View)
A
R
V
OD
R
B
Figure 1. RS-485 Driver DC Test Load Circuit
V
OC
Receiver
Output
Test Point
C
RL
1k
S
1
1k
V
CC
S
2
Figure 2. Receiver Timing Test Load Circuit
DI
A
B
C
L1
R
DIFF
C
L2
A
B
RO
15pF
Output
Under C
L
Test
500
S
1
V
CC
S
2
Figure 4. RS-485 Driver Timing Test Load #2 Circuit
Figure 3. RS-485 Driver/Receiver Timing Test Circuit
+3V
DI
0V
DRIVER
OUTPUT
B
A
f = 1MHz; t
R
< 10ns; t
F
< 10ns
1.5V
t
PLH
V
O
1/2V
O
t
DPLH
t
DPHL
t
PHL
1/2V
O
1.5V
DIFFERENTIAL V
O
+
OUTPUT 0V
V
A
– V
B
V
O
–
t
SKEW =
| t
DPLH -
t
DPHL
|
Figure 5. Driver Propagation Delays
Rev. 5/16/03
t
R
t
F
SP481E Low Power Half-Duplex RS485 Transceivers
© Copyright 2003 Sipex Corporation
4
INPUTS
RE
X
X
X
X
DE
1
1
0
1
DI
1
0
X
X
LINE
CONDITION
No Fault
No Fault
X
Fault
OUTPUTS
B
0
1
Z
Z
A
1
0
Z
Z
INPUTS
RE
DE
0
0
0
0
0
0
1
0
OUTPUTS
A-B
R
+0.2V
1
-0.2V
0
Inputs Open
1
X
Z
Table 2. Receive Function Truth Table
Table 1. Transmit Function Truth Table
+3V
DE
0V
5V
A, B
V
OL
V
OH
A, B
0V
Figure 6. Driver Enable and Disable Times
f = 1MHz; t
R
< 10ns; t
F
< 10ns
1.5V
t
ZL
2.3V
Output normally LOW
1.5V
t
LZ
0.5V
0.5V
t
HZ
2.3V
t
ZH
Output normally HIGH
V
0D2
+
A–B
V
0D2
–
V
OH
R
V
OL
t
PHL
0V
INPUT
0V
1.5V
OUTPUT
1.5V
t
PLH
f = 1MHz; t
R
< 10ns; t
F
< 10ns
t
SKEW =
| t
PHL -
t
PLH
|
Figure 7. Receiver Propagation Delays
+3V
RE
0V
5V
R
V
IL
V
IH
R
0V
1.5V
t
ZH
Output normally HIGH
1.5V
Output normally LOW
0.5V
0.5V
t
HZ
1.5V
f = 1MHz; t
R
< 10ns; t
F
< 10ns
t
ZL
1.5V
t
LZ
Figure 8. Receiver Enable and Disable Times
Rev. 5/16/03
SP481E Low Power Half-Duplex RS485 Transceivers
© Copyright 2003 Sipex Corporation
5
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