1
SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
s
Operates From A Single +3.3V Supply
s
Interoperable With +5V Logic
s
+200mV Receiver Input Sensitivity
s
Slew-Rate Limited For Errorless Data
Transmission to 250Kbps
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-7V to +12V Common-Mode Input
Voltage Range
s
Devices Allow Up To 32 Transceivers
On The Serial Bus
s
Driver/Receiver Enable Lines (SP3494)
s
2nA Low-Power Shutdown Mode (SP3494)
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Compatible With The MAX3488, LTC490
and 75179 Industry Standard Pinouts
(SP3493)
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Compatible With The MAX3486 and 75176
Industry Standard Pinouts (SP3494)
+3.3V Low Power Slew Rate Limited
RS-485/RS-422 Transceivers
SP3493/SP3494
DESCRIPTION
The SP3493 and the 3494 devices are +3.3V, slew-rate limited transceivers that meet the
specifications of the RS-485 and RS-422 serial protocols. The SP3493 and the 3494 devices
are pin-to-pin compatible with the Sipex SP3490 and the SP3481 devices, respectively, as well
as other popular industry standards. The devices feature Sipex's BiCMOS process, allowing
low power operation without sacrificing performance. The slew-rate limited drivers minimize
EMI and reduce reflections caused by improperly terminated cables allowing
error-free data transmission. The SP3493 is a full-duplex slew-rate limited transceiver that will
deliver a data transmission rate up to 250kbps. The SP3494 is a half-duplex slew-rate limited
transceiver that will deliver a data transmission rate up to 2.5Mbps. The SP3494 is equipped
with a low-power shutdown mode and driver/receiver high-Z enable lines.
1
2
3
4
5
6
7
8
R
D
Vcc
GND
R
D
A
B
Z
Y
RO 1
RE 2
DE 3
DI 4
8 V
CC
7 B
6 A
5 GND
D
R
SP3493
SP3494
®
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
SPECIFICATIONS
T
AMB
= T
MIN
to T
MAX
and V
CC
= 3.3V
±
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3493 DRIVER
DC Characteristics
Differential Output Voltage
GND
V
CC
Volts
Unloaded; R =
∞
Ω
;
Figure 1
Differential Output Voltage
2
V
CC
Volts
With Load; R = 50
Ω
; (RS-422);
Figure 1
Differential Output Voltage
1.5
V
CC
Volts
With Load; R = 27
Ω
; (RS-485);
Figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
0.2
Volts
R = 27
Ω
or R = 50
Ω
;
Figure 1
Driver Common-Mode
Output Voltage
3
Volts
R = 27
Ω
or R = 50
Ω
;
Figure 1
Input High Voltage
2.0
Volts
Input Low Voltage
0.8
Volts
Input Current
+10
µ
A
Driver Short-Circuit Current
V
OUT
= HIGH
+250
mA
-7V < V
O
< +12V
V
OUT
= LOW
+250
mA
-7V < V
O
< +12V
SP3493 DRIVER
AC Characteristics
Maximum Data Rate
250
kbps
Driver Input to Output, t
PLH
400
900
1500
ns
Figures 2 and 8
Driver Input to Output, t
PHL
400
900
1500
ns
Figures 2 and 8
Differential Driver Skew
10
ns
t
PHL
(Y) - t
PLH
(Y) , t
PHL
(Z) - t
PLH
(Z) ,
Figures 2 and 8
Figures 2 and 8
Driver Rise or Fall Time
10
30
ns
From 10% to 90%;
Figures 3 and 9
SP3493 RECEIVER
DC Characteristics
Differential Input Threshold
0.2
+0.2
Volts
-7V < V
CM
< 12V
Input Hysteresis
25
mV
V
CM
= 0V
Output Voltage High
V
CC
-0.4
Volts
I
O
= -1.5mA, V
ID
= +200mV
Output Voltage Low
0.4
Volts
I
O
= +2.5mA, V
ID
= -200mV
Input Resistance
12
15
k
Ω
-7V < V
CM
< 12V
Input Current (A, B); V
IN
= 12V
1.0
mA
V
IN
= 12V
Input Current (A, B); V
IN
= -7V
-0.8
mA
V
IN
= -7V
Short-Circuit Current
60
mA
0V < V
O
< V
CC
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
Drivers................................................-0.5V to (V
CC
+0.5V)
Receivers..................................................................
±
14V
Output Voltages
Drivers......................................................................
±
14V
Receivers...........................................-0.5V to (V
CC
+0.5V)
Storage Temperature....................................................-65˚C to +150˚
Power Dissipation per Package
8-pin PDIP (derate11.8mW/
o
C above +70
o
C)...........................1000mW
8-pin NSOIC (derate 6.90mW/
o
C above +70
o
C).........................600mW
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
SPECIFICATIONS (continued)
T
AMB
= T
MIN
to T
MAX
and V
CC
= 3.3V
±
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3493 RECEIVER
AC Characteristics
Maximum Data Rate
250
kbps
Receiver Input to Output, t
PLH
35
70
120
ns
Figures 6 and 11
Receiver Input to Output, t
PHL
35
70
120
ns
Figures 6 and 11
Differential Receiver Skew
10
ns
Figures 6 and 11
SP3493 POWER REQUIREMENTS
Supply Current
1000
2000
µ
A
D = 0 or V
CC
SP3494 DRIVER
DC Characteristics
Differential Output Voltage
GND
V
CC
Volts
Unloaded; R =
∞
;
Figure 1
Differential Output Voltage
2
V
CC
Volts
with load; R = 50
Ω
; (RS-422);
Figure 1
Differential Output Voltage
1.5
V
CC
Volts
with load; R = 27
Ω
; (RS-485);
Figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
0.2
Volts
R = 27
Ω
or R = 50
Ω
;
Figure 1
Driver Common-Mode
Output Voltage
3
Volts
R = 27
Ω
or R = 50
Ω
;
Figure 1
Input High Voltage
2.0
Volts
Applies to DE, DI, RE
Input Low Voltage
0.8
Volts
Applies to DE, DI, RE
Input Current
+10
µ
A
Applies to DE, DI, RE
Driver Short-Circuit Current
V
OUT
= HIGH
+250
mA
-7V < V
O
< +12V
V
OUT
= LOW
+250
mA
-7V < V
O
< +12V
SP3494 DRIVER
AC Characteristics
Maximum Data Rate
2.5
Mbps
RE = V
CC
, DE = V
CC
Driver Input to Output, t
PLH
20
45
75
ns
Figures 2 and 8
Driver Input to Output, t
PHL
20
45
75
ns
Figures 2 and 8
Differential Driver Skew
10
ns
t
DO1
- t
DO2
,
Figures 2 and 9
Driver Rise or Fall Time
30
70
ns
From 10% to 90%,
Figures 3 and
9
Driver Enable to Output High
52
120
ns
Figures 4 and 10
Driver Enable to Output Low
60
120
ns
Figures 5 and 10
Driver Disable Time from Low
40
120
ns
Figures 5 and 10
Driver Disable Time from High
60
120
ns
Figures 4 and 10
SP3494 RECEIVER
DC Characteristics
Differential Input Threshold
-0.2
+0.2
Volts
-7V < V
CM
< +12V
Input Hysteresis
20
mV
V
CM
= 0V
Output Voltage High
V
CC
-0.4
Volts
V
ID
= +200mV, -1.5mA
Output Voltage Low
0.4
Volts
V
ID
= -200mV, 2.5mA
Three-State (High Impedance)
Output Current
+1
µ
A
0V < V
O
< V
CC
; RE = V
CC
Input Resistance
12
15
k
Ω
-7V < V
CM
< +12V
Input Current (A, B); V
IN
= 12V
1.0
mA
DE = 0V, V
CC
= 0V or 3.6V, V
IN
= 12V
Input Current (A, B); V
IN
= -7V
-0.8
mA
DE = 0V, V
CC
= 0V or 3.6V, V
IN
= -7V
Short-Circuit Current
7
60
mA
0V < V
CM
< V
CC
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
SPECIFICATIONS (continued)
T
AMB
= T
MIN
to T
MAX
and V
CC
= +3.3V
±
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3494 RECEIVER
AC Characteristics
Maximum Data Rate
2.5
Mbps
RE = 0V, DE = 0V
Receiver Input to Output, t
PLH
40
70
100
ns
Figures 6 and 11
Receiver Input to Output, t
PHL
40
70
100
ns
Figures 6 and 11
Differential Receiver Skew
10
ns
t
RSKEW
=
t
RPHL
-
t
RPLH
,
Figures 6 and 11
Receiver Enable to
Output Low
35
60
ns
Figures 7 and 12; S
1
closed, S
2
open
Receiver Enable to
Output High
35
60
ns
Figures 7 and 12; S
2
closed, S
1
open
Receiver Disable from Low
35
60
ns
Figures 7 and 12; S
1
closed, S
2
open
Receiver Disable from High
35
60
ns
Figures 7 and 12; S
2
closed, S
1
open
SP3494 SHUTDOWN TIMING
Time to Shutdown
50
75
200
ns
RE = 3.3V, DE = 0V
Driver Enable from Shutdown
to Output High
65
150
ns
Figures 4 and 10
Driver Enable from Shutdown
to Output Low
65
150
ns
Figures 5 and 10
Receiver Enable from
Shutdown to Output High
50
200
ns
Figures 7 and 12; S
2
closed, S
1
open
Receiver Enable from
Shutdown to Output Low
50
200
ns
Figures 7 and 12; S
1
closed, S
2
open
SP3494 POWER REQUIREMENTS
Supply Current
No Load
1000
2000
µ
A
RE, DI = 0V or V
CC
; DE = V
CC
800
1500
µ
A
RE = 0V, DI = 0V or V
CC
; DE = 0V
Shutdown Mode
10
µ
A
DE = 0V, RE=V
CC
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
PIN FUNCTION - SP3493
Pin 1 - V
CC
- Positive supply +3.00 < V
CC
< +3.60
Pin 2 - R - Receiver output.
Pin 3 - D - Driver input.
Pin 4 - GND - Ground connection.
Pin 5 - Y - Non-inverting driver output.
Pin 6 - Z - Inverting driver output.
Pin 7 - B - Inverting receiver input.
Pin 8 - A - Non-inverting receiver input.
1
2
3
4
5
6
7
8
R
D
Vcc
GND
R
D
A
B
Z
Y
PIN FUNCTION - SP3494
Pin 1 – RO – Receiver Output.
Pin 2 – RE – Receiver Output Enable Active LOW.
Pin 3 – DE – Driver Output Enable Active HIGH.
Pin 4 – DI – Driver Input.
Pin 5 – GND – Ground Connection.
Pin 6 – A – Driver Output/Receiver Input
Non-inverting.
Pin 7 – B – Driver Output/Receiver Input Inverting.
Pin 8 – Vcc – Positive Supply +3.00V < V
CC
< +3.60V
SP3494
Pinout
RO 1
RE 2
DE 3
DI 4
8 V
CC
7 B
6 A
5 GND
D
R
SP3493
Pinout
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
DESCRIPTION
The SP3493/3494 are +3.3V transceivers that
meet the electrical specifications of the
RS-485 and RS-422 serial protocols. The
SP3493/3494 feature Sipex's BiCMOS process
allowing low power operation without
sacrificing performance.
The SP3493 device is a +3.3V full-duplex
transceiver that is pin-to-pin compatible with
the Sipex SP3490 and SP490 devices as well as
popular industry standards such as the
MAX3488, the LTC490, and the 75179. The
SP3493 has a slew-rate limited driver with a
data transmission rate of 250kbps.
The SP3494 device is a +3.3V half-duplex
transceiver that is pin-to-pin compatible with
the Sipex SP3481 and SP481 devices as well as
popular industry standards such as the MAX3486
and the 75176. The SP3494 has a slew-rate
limited driver with a data transmission rate of
2.5Mbps.
Drivers
The SP3493/3494devices both have differential
outputs. The typical voltage output swing with
no load will bo 0V to V
CC
. With worst case
loading of 54
Ω
across the differential outputs,
the driver can maintain greater than 1.5V voltage
levels.
The SP3494 device has an enable control line
which is active HIGH. A logic HIGH on DE (pin
3) will enable the differential driver outputs.
A logic LOW on DE (pin 3) will force the driver
outputs at high impedance (high-Z). The SP3493
device does not have a driver enable.
The slew-rate limited SP3493/SP3494 drivers
will operate up to 250kbps and 2.5Mbps,
respectively. In addition to adhering to the
250mA I
SC
maximum limit on the driver output,
the driver output short-circuit protection will
allow the devices to withstand an infinite short
circuit over the -7.0V to +12V common mode
range without damage.
Receivers
The receivers have differential inputs with an
input sensitivity as low +200mV. Input
impedance of the receivers is typically 15k
Ω
(12k
Ω
minimum). A wide common mode range
of -7V to +12V allows for large ground potential
differences between systems.
Both the SP3493/SP3494 receivers are
equipped with fail-safe which guarantees that
the receiver outputs will be in a high state
when the input is left unconnected.
The SP3494 receiver has a high impedance
(high-Z) enable control pin. A logic LOW on
RE (pin 2) will enable the receiver; a logic
HIGH on RE (pin 2) will disable the receiver.
The SP3494 is equipped with a shutdown mode.
To enable the shutdown state, both the driver
and receiver must be disabled simultaneously.
A logic LOW on DE (pin 3) and a logic HIGH
on RE (pin 2) will put the SP3494 into shutdown.
In shutdown, the supply current will drop to 2nA
typical, 1
µ
A maximum.
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
INPUTS
OUTPUTS
LINE
RE
DE
DI CONDITION
B
A
X
1
1
No Fault
0
1
X
1
0
No Fault
1
0
X
0
X
X
Z
Z
INPUTS
OUTPUTS
RE
DE
A - B
R
0
0
+0.2V
1
0
0
-0.2V
0
0
0
Inputs Open
1
1
0
X
Z
Table 1. Transmit Function Truth Table
Table 2. Receive Function Truth Table
Figure 1. Driver DC Test Load Circuit
Figure 7. Receiver Enable and Disable Timing Circuit
R
R
V
OC
D
V
CC
V
OD
GENERATOR
(NOTE 1)
50
Ω
V
CC
S1
V
DM
R
L
= 27
Ω
OUT
C
L
= 15pF
(NOTE 2)
V
OM
= 1.5V
V
OH
+ V
OL
2
D
GENERATOR
(NOTE 1)
50
Ω
S1
R
L
= 110
Ω
OUT
C
L
= 50pF
(NOTE 2)
V
OM
= 1.5V
V
OH
+ V
OL
2
D
GENERATOR
(NOTE 1)
50
Ω
S1
R
L
= 110
Ω
OUT
C
L
= 50pF
(NOTE 2)
D
0V OR 3V
V
CC
GENERATOR
(NOTE 1)
50
Ω
1.5V
0V
V
ID
R
OUT
C
L
= 15pF
(NOTE 2)
V
OM
= V
CC
2
1.5V
-1.5V
S3
V
ID
GENERATOR
(NOTE 1)
50
Ω
C
L
= 15pF
(NOTE 2)
R
1k
S1
S2
V
CC
Figure 5. Driver Enable and Disable Timing Circuit,
Output LOW
GENERATOR
(NOTE 1)
50
Ω
C
L
OUT
D
V
CC
R
L
=
60
Ω
C
L
= 15pF (NOTE 2)
Figure 3. Driver Differential Output Delay and
Transition Time Circuit
Figure 2. Driver Propagation Delay Test Circuit
Figure 6. Receiver Propagation Delay Test Circuit
Figure 4. Driver Enable and Disable Timing Circuit,
output HiGH
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SP3493/3494DS/03 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2000 Sipex Corporation
Figure 8. Driver Propagation Delay Waveforms
Figure 12. Receiver Enable and Disable Waveforms
Figure 11. Receiver Propagation Delay Waveforms
Figure 10. Driver Enable and Disable Timing Waveforms
0V
V
OH
t
PLH
t
PHL
V
OM
t
PHL
t
PLH
3V
V
OL
V
OH
1.5V
1.5V
INPUT
Y OUTPUT
V
OM
Z OUTPUT
V
OL
V
OM
V
OM
V
OM
= V
OH
+ V
OL
2
≈
1.5V
0V
V
OH
t
PZH
0.25V
t
PHZ
V
OM
t
PZL
t
PLZ
3V
V
OL
V
CC
1.5V
1.5V
DE
OUTPUT
HIGH
V
OM
0.25V
0V
OUTPUT
LOW
V
OM
= V
OH
+ V
OL
2
≈
1.5V
3V
0V
V
CC
t
RPLH
1.5V
t
RPHL
V
OM
V
OM
0V
1.5V
INPUT
OUTPUT
V
OM
= V
CC
2
3V
0V
t
PRHZ
1.5V
t
PRZH
t
PRSH
1.5V
1.5V
10%
0V
V
OH
RE
OUTPUT
S1 is open
S2 is closed
S3 = 1.5V
3V
0V
t
PRLZ