SIPEX SP495ET

®
SP495
Quad Differential RS-485 Transceiver
■ Pinout for SCSI Interface
■ Meets EIA-485 Standard for Multipoint
Bus Transmission
■ +5V-Only Power Supply Required
■ Receiver Fail-Safe Mode
■ Low Power BiCMOS Technology
■ Glitch-Free Power-Up/Down
■ Available in 20-Pin Plastic SOIC
■ Pin Compatible with DS36954
DESCRIPTION…
The SP495 is a quad differential line driver/receiver meeting both RS-485 and RS-422
standards at data rates beyond 10Mbps. The SP495 features three half-duplex transceivers
suitable for data bus connections and a fourth full-duplex transceiver with independent driver,
receiver enables. Ideal for use as a control bus transceiver. A complete SCSI initiator or target
interface can be implemented using five SP495s. Propagation Delay Skew is tightly specified
to aid in parallel interface designs. The SP495 is available in a 20-pin plastic SOIC package
for operation over the commercial and industrial temperature ranges. For PLCC availability,
please consult factory.
OA1 OB1
OA2 OB2
20
18
19
17
2
1
SP495
13
R2
3
D3
4
DR2 DE2/ RE2
12
R3
D2
DR1 DE1/RE1
OA4 OB4
15 14
16
R1
D1
cc OA3 OB3
SP495V
11
6
GND
DR3 DE3/ RE3
5
Quad Differential RS-485 Transceiver
1
R4
D4
8
9
DI4 DE4
7
10
RO4 RE4
© Copyright 2000 Sipex Corporation
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.
VCC............................................................................................................................+7V
Input Voltages
Logic...................................................-0.5V to (VCC+0.5V)
Drivers................................................-0.5V to (VCC+0.5V)
Receivers....................................................................15V
Output Voltages
Logic...................................................-0.5V to (VCC+0.5V)
Drivers...........................................................-8V to 12.5V
Receivers...........................................-0.5V to (VCC+0.5V)
Storage Temperature....................................................-65˚C to +150˚C
Power Dissipation.....................................................................1000mW
SPECIFICATIONS
TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted.
PARAMETERS
DRIVER
DC Characteristics
Differential Output Voltage
Differential Output Voltage
MIN.
TYP.
MAX.
UNITS
CONDITIONS
GND
2
VCC
VCC
Volts
Volts
Differential Output Voltage
Change in Magnitude of Driver
Differential Output Voltage for
1.5
VCC
Volts
Unloaded; R = ∞ ; see Figure 1
With Load; R = 50Ω; (RS-422);
see Figure 1
With Load; R = 27Ω; (RS-485); see Figure 1
Complimentary States
Driver Common-Mode
Output Voltage
Input High Voltage
Input Low Voltage
Input Current
Driver Short-Circuit Current
VOUT = HIGH
VOUT = LOW
0.2
Volts
R = 27Ω or R = 50Ω; see Figure 1
0.8
±10
Volts
Volts
Volts
µA
R = 27Ω or R = 50Ω; see Figure 1
Applies to DRx, DEx/ REx
Applies to DRx, DEx/ REx
Applies to DRx, DEx/ REx
±250
±250
mA
mA
-7V ≤ VO ≤ 10V
-7V ≤ VO ≤ 10V
RDIFF = 54Ω, CL1 = CL2 = 100pF
tPLH; RDIFF = 54Ω, CL1 = CL2 = 100pF;
see Figures 3 and 6
tPHL; RDIFF = 54Ω, CL1 = CL2 = 100pF;
see Figures 3 and 6
see Figures 3 and 6
3
2.0
DRIVER
AC Characteristics
Maximum Driver Data Rate
Driver Input to Output
10
20
30
60
Mbps
ns
Driver Input to Output
20
30
60
ns
Driver Skew
Driver Rise or Fall Time
10
15
40
ns
Driver Enable to Output HIGH
40
70
ns
Driver Enable to Output LOW
40
70
ns
Driver Disable Time from LOW
40
70
ns
Driver Disable Time from HIGH
40
70
ns
RECEIVER
DC Characteristics
Differential Input Threshold
Input Hysteresis
Output Voltage HIGH
SP495
3
ns
-0.2
+0.2
70
3.5
Volts
mV
Volts
Quad Differential RS-485 Transceiver
2
From 10% to 90%; RDIFF = 54Ω,
CL1 = CL2 = 100pF; see Figures 3 and 6
CL1 = CL2 = 100pF; see Figures
4 and 7; S2 closed
CL1 = CL2 = 100pF; see Figures
4 and 7; S1 closed
CL1 = CL2 = 15pF; see Figures
4 and 7; S1 closed
CL1 = CL2 = 15pF; see Figures
4 and 7; S2 closed
-7V ≤ VCM ≤ 12V
VCM = 0V
IO = -4mA, VID = +200mV
© Copyright 2000 Sipex Corporation
SPECIFICATIONS (continued)
TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted.
PARAMETERS
RECEIVER
DC Characteristics
MIN.
UNITS
CONDITIONS
0.4
Volts
IO = +4mA, VID = -200mV
10
±1.0
-0.8
85
µA
kΩ
mA
mA
mA
0.4V ≤ VO ≤ 2.4V; DEx/ REx = 5V
-7V ≤ VCM ≤ 12V
DE = 0V, VCC = 0V or 5.25V, VIN = 12V
DE = 0V, VCC = 0V or 5.25V, VIN = -7V
0V ≤ VO ≤ VCC
60
200
Mbps
ns
Receiver Input to Output
60
200
ns
Diff. Receiver Skew ItPLH-tPHLI
13
DEx/ REx = 0V
tPLH; RDIFF = 54Ω,
CL1 = CL2 = 100pF; Figures 3 & 8
tPHL; RDIFF = 54Ω,
CL1 = CL2 = 100pF; Figures 3 & 8
RDIFF = 54Ω; CL1 = CL2 = 100pF;
Receiver Enable to Output LOW
Receiver Enable to Output HIGH
Receiver Disable from LOW
Receiver Disable from HIGH
POWER REQUIREMENTS
Supply Voltage
+4.75
Supply Current
ENVIRONMENTAL AND
MECHANICAL
45
45
45
45
70
70
70
70
2
Output Voltage LOW
Three State (high impedance)
Output Current
Input Resistance
Input Current (A, B); VIN = 12V
Input Current (A, B); VIN = -7V
Short-Circuit Current
RECEIVER
AC Characteristics
Maximum Data Rate
Receiver Input to Output
12
TYP.
±0.5
15
MAX.
10
ns
Figures 3 & 8
Operating Temperature
Commercial (_C_)
Industrial (_E_)
Storage Temperature
Package
Plastic LCC (_L)
0
-40
-65
ns
ns
ns
ns
CRL = 15pF; Figures 2 and 9; S1 closed
CRL = 15pF; Figures 2 and 9; S2 closed
CRL = 15pF; Figures 2 and 9; S1 closed
CRL = 15pF; Figures 2 and 9; S2 closed
+5.25
5
Volts
mA
DEx/ REx, DRx = 0V or VCC
+70
+85
+150
°C
°C
°C
A
R
VOD
VCC
S1
CRL
R
1k
Test Point
Receiver
Output
1k
VOC
S2
B
Figure 1. Driver DC Test Load Circuit
Figure 2. Receiver Timing Test Load Circuit
3V
DE
DI
CL1
A
A
RDIFF
Output
Under
Test
RO
B
B
CL2
15pF
500
S1
VCC
CL
S2
Figure 3. Driver/Receiver Timing Test Circuit
SP495
Figure 4. Driver Timing Test Load #2 Circuit
Quad Differential RS-485 Transceiver
3
© Copyright 2000 Sipex Corporation
f = 1MHz; tR < 10ns; tF < 10ns
+3V
1.5V
DI
1.5V
0V
DRIVER
OUTPUT
B
tPLH
tPHL
tPLH
VO 1/2VO
1/2VO
A
DIFFERENTIAL VO+
OUTPUT 0V
VA – VB VO–
tSKEW
tSKEW
tR
tF
Figure 6. Driver Propagation Delays
f = 1MHz; tR < 10ns; tF < 10ns
+3V
1.5V
DE
0V
1.5V
tZL
tLZ
5V
2.3V
A, B
VOL
VOH
A, B
2.3V
0V
Output normally LOW
0.5V
Output normally HIGH
0.5V
tZH
tHZ
Figure 7. Driver Enable and Disable Times
f = 1MHz; tR 10ns; tF 10ns
V0D2+
A–B
0V
VOH
1.5V
R
VOL
0V
INPUT
V0D2–
1.5V
OUTPUT
tPHL
tPHL
Figure 8. Receiver Propagation Delays
SP495
Quad Differential RS-485 Transceiver
4
© Copyright 2000 Sipex Corporation
+3V
RE
0V
1.5V f = 1MHz; t < 10ns; t < 10ns
R
F
tZL
1.5V
tLZ
5V
1.5V
R
VIL
Output normally LOW
0.5V
Output normally HIGH
0.5V
VIH
R
1.5V
0V
tZH
tHZ
Figure 9. Receiver Enable and Disable Times
DESCRIPTION
General Description...
The three half-duplex drivers of the SP495 have
independent Driver Enable control lines which
are active HIGH. A logic HIGH on DEx (pins 1,
4, or 5 of the SP495) will enable the addressed
differential driver output. A logic LOW on DEx
will tri-state the driver output and enable the
receiver. The fourth driver is controlled by its
own DE4 Enable line and can be used in half duplex or full-duplex modes.
The SP495 is a quad differential transceiver that
meets the requirements of RS-485, RS-422, and
differential SCSI at data rates to beyond 10Mbps.
Fabricated with a proprietary Sipex BiCMOS
process, the SP495 requires only a fraction of the
power of older bipolar designs.
The SP495 features three half-duplex transceivers
suitable for data bus connections and a fourth
full-duplex transceiver with independent enables
ideal for use as a control bus transceiver. A
complete SCSI initiator or target interface can be
implemented using five SP495s.
Receivers...
The differential receivers for the SP495 have an
input sensitivity of ±200mV. Input impedance is
typically 15kΩ (12kΩ minimum). A wide
common mode range of -7V to +12V allows for
large ground potential differences between widely
separated systems. These receivers are equipped
with a fail-safe feature which guarantees that the
receiver output will be in a HIGH state when the
input is left unconnected (note: this feature
operates with floating inputs, not terminated
inputs).
The RS-485 standard is ideal for multi-drop
applications and for long-distance interfaces.
RS-485 allows up to 32 drivers and 32 receivers
to be connected to a single data bus, making it an
ideal choice for multi-drop applications. Since
the cabling can be as long as 4,000 feet, RS-485
transceivers are specified for operation with a
wide (-7V to +12V) common mode range to
accommodate ground potential differences.
Because RS-485 is a low impedance differential
interface, data is virtually immune to noise in the
transmission line.
Like the half-duplex drivers, the three half-duplex
receivers of the SP495 have independent Receiver Enable control lines which are active
LOW. A logic LOW on REx (pins 1, 4, or 5 of
the SP495) enables the differential receivers. A
logic HIGH on REx tri-states the receivers. The
fourth receiver is controlled by its own RE4
Enable line and can be used in half-duplex or
full-duplex modes.
Drivers...
The differential drivers for the SP495 have typical
output voltage swings (no load) of 0 to +5Volts.
With loading to the RS-485 specification (54Ω),
drivers must maintain outputs greater than 1.5V.
SP495
Quad Differential RS-485 Transceiver
5
© Copyright 2000 Sipex Corporation
ORDERING INFORMATION
Model
Temperature Range
Package
SP495CT. ......................................................... 0˚C to +70˚C ...................................................... 20-Pin SOIC
SP495ET ........................................................ -40˚C to +85˚C .................................................... 20-Pin SOIC
For PLCC availability, please consult factory.
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: [email protected]
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.
SP495
Quad Differential RS-485 Transceiver
6
© Copyright 2000 Sipex Corporation