SP334 [SIPEX]
Programmable RS-232/RS-485 Transceiver; 可编程RS - 232 / RS - 485收发器
| 型号： | SP334 |
| 厂家： | 
SIPEX CORPORATION |
| 描述： | Programmable RS-232/RS-485 Transceiver |
| 文件： | 总12页 (文件大小：158K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
®
SP334
Programmable RS-232/RS-485 Transceiver
■ +5V Only Operation
■ Software Programmable RS-232 or RS-
485 Selection
■ Three RS-232 Drivers and Five Receivers
in RS-232 Mode
■ Two RS-485 Full-Duplex Transceivers in
RS-485 Mode
■ Full Differential Driver Tri-State (Hi-Z)
Control
■ Receiver Output Tri-State Control
DESCRIPTION…
TheSP334isaprogrammableRS-232and/orRS-485transceiverIC. TheSP334containsthree
driversandfivereceiverswhenselectedinRS-232mode;andtwodriversandtworeceiverswhen
selected in RS-485 mode.
The RS-232 transceivers can typically operate at 230kbps while adhering to the RS-232
specifications. TheRS-485transceiverscanoperateupto10MbpswhileadheringtotheRS-485
specifications. TheRS-485driverscanbedisabled(High-Zoutput)bytheTXENenablepin. The
RS-232 and RS-485 receiver outputs can be disabled by the RXEN enable pin.
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
TI3
TXEN(n/c)
TX4(n/c)
TX3
TI2
TI1
3
RXEN
RS232/RS485
RI5
RX5
RX4
RX3
RX2
RX1
RI4
4
5
VCC
TX1
TX2
GND
C1+
V+
C2+
C1–
C2–
6
SP334
7
8
9
10
11
12
13
14
RI3
RI2
RI1
V–
(in RS-232 mode)
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© 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.
V
CC...........................................................................+7V
Package Derating:
28-pin Plastic DIP
øJA....................................................40°C/W
28-pin Plastic SOIC
øJA....................................................40°C/W
StorageTemperature..........................-65˚Cto+150˚C
Power Dissipation
28-pinPlasticDIP...........................1000mW
28-pin Plastic SOIC.......................1000mW
SPECIFICATIONS
Typically 25°C @ Vcc = +5V unless otherwise noted.
MIN.
TYP.
MAX.
UNITS
CONDITIONS
LOGIC INPUTS
VIL
VIH
0.8
Volts
Volts
2.0
LOGIC OUTPUTS
VOL
VOH
0.4
Volts
Volts
µA
IOUT= -3.2mA
IOUT= 1.0mA
0.4V ≤ VOUT ≤ +2.4V
2.4
Output Tri-state Leakage
10
RS-232 DRIVER
DC Characteristics
HIGH Level Output
LOW Level Output
Open Circuit Voltage
Short Circuit Current
Power Off Impedance
+5.0
–15.0
–15
+15
–5.0
+15
Volts
Volts
Volts
mA
RL=3kΩ, VIN=0.8V
RL=3kΩ, VIN=2.0V
±100
VOUT = 0V
Vcc = 0V, Vout = ±2.0V
300
Ω
AC Characteristics
Slew Rate
30
V/µs
µs
RL=3kΩ, CL= 50pF
VCC = +5.0V, TA @ +25°C
RL=3kΩ, CL=2500pF ;
between ±3V, TA @ +25°C
RL=3kΩ, CL=2500pF
Transition Time
1.56
Maximum Data Rate
120
235
kbps
Propagation Delay
tPHL
tPLH
2
2
8
8
µs
µs
Measured from 1.5V of VIN
to 50% of VOUT; RL=3kΩ
RS-232 RECEIVER
DC Characteristics
HIGH Threshold
1.7
1.2
3.0
Volts
Volts
Volts
kΩ
LOW Threshold
Receiver Open Circuit Bias
Input Impedance
0.8
3
+2.0
7
5
VIN = +15V to –15V
AC Characteristics
Maximum Data Rate
Propagation Delay
tPHL
120
235
kbps
0.25
0.25
1
1
µs
µs
Measured from 50% of VIN
to 1.5V of VOUT.
tPLH
RS-485 DRIVER
DC Characteristics
Open Circuit Voltage
Differential Output
6.0
5.0
Volts
Volts
1.5
RL=54Ω, CL=50pF
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
2
SPECIFICATIONS
Typically 25°C @ Vcc = +5V unless otherwise noted.
MIN.
TYP.
MAX.
UNITS
CONDITIONS
|VT| - |VT|
RS-485 DRIVER
Balance
Common-Mode Output
±0.2
3.0
Volts
Volts
mA
Output Current
Short Circuit Current
28.0
10
RL=54Ω
Terminated in –7V to +10V
±250
mA
AC Characteristics
Maximum Data Rate
Output Transition Time
Propagation Delay
tPHL
Mbps
ns
RL=54Ω
Rise/fall time, 10%–90%
See Figures 3A & 5
RDIFF=54Ω, CL1=CL2=100pF
RDIFF=54Ω, CL1=CL2=100pF
per figure 5, tSKEW = |tDPLH - tDPHL
30
80
80
5
120
120
20
ns
ns
ns
tPLH
Driver Output Skew
|
RS-485 RECEIVER
DC Characteristics
Inputs
Common Mode Range
Receiver Sensitivity
Input Impedance
–7.0
12
+12.0
±0.2
Volts
Volts
kΩ
–7V ≤ VCM ≤ +12V
–7V ≤ VCM ≤ +12V
15
AC Characteristics
Maximum Data Rate
Propagation Delay
tPHL
10
Mbps
See Figures 3A & 7
130
130
10
200
200
20
ns
ns
ns
RDIFF=54Ω, CL1=CL2=100pF
RDIFF=54Ω, CL1=CL2=100pF
tSKEW= | tPLH – tPHL |; RDIFF=54Ω,
CL1=CL2=100pF, see Figure 8
tPLH
Differential Receiver Skew
ENABLE TIMING
RS-485 Driver
Enable Time
Enable to Low
Enable to High
Disable Time
Disable From Low
Disable From High
RS-485 Receiver
Enable Time
Enable to Low
Enable to High
Disable Time
See Figures 4 & 6
CL=15pF, S1 Closed
CL=15pF, S2 Closed
See Figures 4 & 6
CL=15pF, S1 Closed
CL=15pF, S2 Closed
100
100
150
150
ns
ns
100
100
120
120
ns
ns
See Figures 2 & 8
CL=15pF, S1 Closed
CL=15pF, S2 Closed
See Figures 2 & 8
CL=15pF, S1 Closed
CL=15pF, S2 Closed
100
100
150
150
ns
ns
Disable From Low
Disable From High
100
100
120
120
ns
ns
POWER REQUIREMENTS
Supply Voltage VCC
+4.75
+5.25
Volts
Supply Current ICC
No Load (Tx Disabled)
No Load (RS-232 Mode)
No Load (RS-485 Mode)
12
20
15
20
50
50
mA
mA
mA
TXEN = 0V
RS232/RS485 = 0V
RS232/RS485 = +5V
ENVIRONMENTAL
Operating Temperature
Commercial (..C..)
Industrial (..E..)
0
–40
–65
+70
+85
+150
°C
°C
°C
Storage Temperature
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
3
RECEIVER INPUT GRAPH
RS-485 RECEIVER
+1.0mA
+12V
–7V –3V
+6V
1 Unit Load
Maximum Input Current
versus Voltage
–0.6mA
TEST CIRCUITS
A
1KΩ
Test Point
Receiver
R
R
V
CC
Output
S
S
1
C
RL
1KΩ
V
OD
V
OC
2
B
Figure 1. Driver DC Test Load Circuit
Figure 2. Receiver Timing Test Load Circuit
C
C
L1
V
CC
A
B
S
1
A
B
DI
R
L
500Ω
RO
Output
Under
Test
L2
C
L
15pF
S
2
Figure 4. Driver Timing Test Load #2 Circuit
Figure 3a. Driver/Receiver Timing Test Circuit
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
4
SWITCHING WAVEFORMS
f ≥ 1MHz; t ≤ 10ns; t ≤ 10ns
R
F
+3V
1.5V
1.5V
DRIVER INPUT
0V
t
t
PHL
PLH
B
1/2V
1/2V
O
O
DRIVER
OUTPUT
V
O
A
t
t
DPLH
DPHL
+
V
V
DIFFERENTIAL
OUTPUT
O
0V
–
V
– V
O
A
B
t
t
F
R
t
= |t
- t
|
SKEW
DPLH DPHL
Figure 5. Driver Propagation Delays
f = 1MHz; tR ≤ 10ns; tF ≤ 10ns
1.5V
+3V
1.5V
0V
5V
TxEN
A, B
tZL
2.3V
tLZ
Output normally LOW
Output normally HIGH
0.5V
0.5V
VOL
VOH
A, B
2.3V
tZH
0V
tHZ
Figure 6. Driver Enable and Disable Times
f = 1MHz; tR ≤ 10ns; tF ≤ 10ns
+
–
V0D2
0V
0V
A – B
INPUT
V0D2
VOH
RECEIVER OUT
VOL
1.5V
1.5V
OUTPUT
tPHL
tPLH
Figure 7. Receiver Propagation Delays
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
5
+3V
0V
1.5V
1.5V
R EN
X
f = 1MHz; t ≤ 10ns; t ≤ 10ns
R
F
t
t
LZ
ZL
5V
1.5V
RECEIVER OUT
Output normally LOW
Output normally HIGH
0.5V
0.5V
V
IL
V
IH
RECEIVER OUT
0V
1.5V
t
t
HZ
ZH
t
= |t
- t
|
SKEW
PHL PLH
Figure 8. Receiver Enable and Disable Times
TTL
Input
Driver
Output
Figure 9. Typical RS-232 Driver Output
Figure 10. Typical RS-485 Driver Output
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
6
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
TI3
TXEN(n/c)
TX4(n/c)
TX3
TI2
TI1
3
RXEN
RS232/RS485
RI5
RX5
RX4
RX3
RX2
RX1
RI4
4
5
VCC
TX1
TX2
GND
C1+
V+
C2+
C1–
C2–
6
SP334
7
8
9
10
11
12
13
14
RI3
RI2
RI1
V–
(in RS-232 mode)
Figure 11. SP334 Pinout
+5V
+5V
5
9
0.1µF
C1+
5
VCC
0.1µF
0.1µF
12
9
10
VCC
C1+
C1-
V+
11
10
14
SP334
14
C2+
0.1µF
0.1µF
12
V–
V+
V–
C1-
0.1µF
13
25
C2-
11
SP334
0.1µF
C2+
0V
13
RS232/RS485
0.1µF
C2-
Vcc
400KΩ
2
TX1
TX2
TX3
6
7
27 TI1
28 TI2
TXEN
Vcc
TTL/CMOS
TTL/CMOS
T1
T2
T3
RS-232
RS-232
TTL/CMOS
TTL/CMOS
TTL/CMOS
Vcc
400KΩ
7
TX2
400KΩ
RS-485
27
1
TI1
T1
Vcc
400KΩ
6
3
TX1
TX4
RS-485
RS-485
4
3
1
2
TI3
Vcc
400KΩ
RS-232
TI3
N/C
N/C
TTL/CMOS
TTL/CMOS
T3
R1
4
TX3
RI1
RS-485
RS-485
RS-232
TTL/CMOS
R1
R2
19 RX1
20 RX2
15
16
5KΩ
RI1 15
RI2 16
19 RX1
RI2
15KΩ
15KΩ
TTL/CMOS
RS-232
5KΩ
RS-485
RI3
TTL/CMOS
TTL/CMOS
TTL/CMOS
RS-232
RS-232
R3
R4
RX3
17
21
5KΩ
RI4 18
RI3 17
RS-485
RS-485
21 RX3
26
15KΩ
15KΩ
RI4
TTL/CMOS
TTL/CMOS
R3
22 RX4
5KΩ
18
24
26
RI5
R5
RS-232
RX5
23
8
RXEN
5KΩ
25
+5V
8
RS232/RS485
GND
TTL/CMOS
GND
RXEN
Figure 12. Typical Operating Circuit
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
7
capacitorC1 isswitchedto+5Vandthenegative
sideisconnectedtoground, andthecyclebegins
again.
THEORY OF OPERATION
The SP334 is made up of four separate circuit
blocks — the charge pump, drivers, receivers,
and decoder. Each of these circuit blocks is
described in more detail below.
Since both V+ and V– are separately generated
fromVCC inano–loadcondition, V+andV– will
be symmetrical. Older charge pump approaches
that generate V– from V+ will show a decrease
in the magnitude of V– compared to V+ due to
the inherent inefficiencies in the design.
Charge–Pump
The charge pump is a Sipex–patented design
(U.S. 5,306,954) and uses a unique approach
compared to older less–efficient designs. The
charge pump still requires four external
capacitors, but uses a four–phase voltage
shifting technique to attain symmetrical 10V
power supplies. Figure 17(a) shows the
waveform found on the positive side of capcitor
C2, and figure 17(b) shows the negative side of
capcitor C2. There is a free–running oscillator
that controls the four phases of the voltage
shifting. A description of each phase follows.
The clock rate for the charge pump typically
operates at 15kHz. The external capacitors
must be a minimum of 0.1µF with a 16V
breakdown rating.
External Power Supplies
For applications that do not require +5V only,
external supplies can be applied at the V+ and
V– pins. The value of the external supply volt-
ages must be no greater than ±l0V. The current
drain for the ±10V supplies is used for RS232.
For the RS-232 driver the current requirement
will be 3.5mA per driver. The external power
supplies should provide a power supply se-
quence of :+l0V, then +5V, followed by –l0V.
Phase 1
— VSS charge storage —During this phase of
the clock cycle, the positive side of capacitors
C1 and C2 are initially charged to +5V. Cl+– is
then switched to ground and charge on C1 is
–
+
transferred to C2 . Since C2 is connected to
+5V, the voltage potential across capacitor C2
is now 10V.
Drivers
TheSP334hasthreeindependentRS-232single-
ended drivers and two differential RS-485
drivers. Control for the mode selection is done
by the RS-232/RS-485 select pin. The drivers
are pre-arranged such that for each mode of
Phase 2
— VSS transfer — Phase two of the clock
connects the negative terminal of C2 to the VSS
storage capacitor and the positive terminal of C2
to ground, and transfers the generated –l0V to
C3. Simultaneously, the positive side of capaci-
tor C 1 is switched to +5V and the negative side
is connected to ground.
V
= +5V
CC
C
+5V
4
+
–
+
V
V
Storage Capacitor
Storage Capacitor
DD
SS
+
–
+
–
C
C
2
Phase 3
1
–
— VDD charge storage — The third phase of the
clock is identical to the first phase — the charge
transferred in C1 produces –5V in the negative
terminal of C1, which is applied to the negative
side of capacitor C2. Since C2 is at +5V, the
voltage potential across C2 is l0V.
C
–5V
–5V
3
Figure 13. Charge Pump Phase 1.
+
V
= +5V
CC
C
+
4
Phase 4
–
+
V
V
Storage Capacitor
Storage Capacitor
DD
+
–
+
–
— VDD transfer — The fourth phase of the
clock connects the negative terminal of C2 to
ground and transfers the generated l0V across
C2 to C4, the VDD storage capacitor. Again,
simultaneously with this, the positive side of
C
C
2
1
–
SS
C
–10V
3
Figure 14a. Charge Pump Phase 2.
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
8
±5V with a full load of 3kΩ and 2500pF applied
as specified. These drivers can also operate at
least 120kbps.
V
= +5V
CC
C
+
+5V
4
–
+
V
V
Storage Capacitor
Storage Capacitor
DD
+
–
+
–
C
C
2
1
When programmed to RS-485 mode, the
differential RS-485 drivers produce complaint
RS-485 signals. Each RS-485 driver outputs
a unipolar signal on each output pin with a
magnitude of at least 1.5V while loaded with
a worst case of 54Ω between the driver's two
output pins. The signal levels and drive
capability of the RS-485 drivers allow the
drivers to also comply with RS-422 levels. The
transmission rate for the differential drivers is
10Mbps.
–
SS
C
–5V
–5V
3
Figure 15. Charge Pump Phase 3.
V
= +5V
CC
C
+
+10V
4
–
+
V
V
Storage Capacitor
Storage Capacitor
DD
SS
+
–
+
–
C
C
2
1
–
C
3
Receivers
The SP334 has five single-ended receivers
when programmed for RS-232 mode and two
differential receivers when programmed for
RS-485 mode.
Figure 16. Charge Pump Phase 4.
operation the relative position and functionality
of the drivers are set up to accommodate the
selected interface mode. As the mode of the
drivers is changed, the electrical characteristics
willchangetosupporttherequirementsofclock,
data, and control line signal levels. Unused
driver inputs can be left floating; however, to
ensure a desired state with no input signal,
pull–up resistors to +5V or pull–down resistors
to ground are suggested. Since the driver inputs
are both TTL or CMOS compatible, any value
resistor less than 100kΩ will suffice.
Control for the mode selection is done by the
same select pin as the drivers. As the operating
mode of the receivers is changed, the electrical
characteristics will change to support the
requirements of the appropriate serial standard.
Unused receiver inputs can be left floating
without causing oscillation. To ensure a desired
state of the receiver output, a pull–up resistor of
100kΩ to +5V should be connected to the
inverting input for a logic low, or the
non–inverting input for a logic high. For
single-ended receivers, a pull–down resistor to
ground of 5kΩ is internally connected, which
will ensure a logic high output.
When in RS-232 mode, the single-ended RS-
232 drivers produce compliant RS-232E and
ITU V.28 signals. Each of the three drivers
output single-ended bipolar signals in excess of
+10V
a) C2+
GND
GND
b) C2-
-10V
Figure 17. Charge Pump Waveforms
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
9
outputs. The drivers can only be tri-stated in
RS-485 mode. The drivers are always active in
RS-232 mode.
The RS-232 receiver has a single–ended input
with a threshold of 0.8V to 2.4V. The RS-232
receiver has an operating voltage range of ±15V
and can receive signals up to 120kbps. RS-232
receivers are used in RS-232 mode for all signal
types include data, clock, and control lines of
the RS-232 serial port.
The receiver outputs can also be tri-stated by
use of the RXEN pin. A logic LOW will enable
the receiver outputs and a logic HIGH will
tri-state the outputs. The receiver tri-state
capability is offered for both RS-232 and
RS-485 modes. The input impedance if the
receivers during tri-state is at least 12kΩ.
The differential RS-485 receiver has an input
impedance of 15kΩ and a differential threshold
of ±200mV. Since the characteristics of an RS-
422 receiver are actually subsets of RS485, the
receivers for RS-422 requirements are identical
to the RS-485 receivers. All of the differential
receivers can receive data up to 10Mbps.
Applications
The SP334 allows the user flexibility in having
a RS-232 or RS-485 serial port without using
two different discrete active ICs. Figure 18
shows a connection to a standard DB-9 RS-232
connector. In RS-485 mode, the SP334 is a full
duplex transceiver, however, a half duplex
configuration can be made by connecting the
driver outputs to the receiver inputs.
Enable Pins
The SP334 drivers can be enabled by use of the
TXEN pin. A logic HIGH will enable the driver
outputs and a logic LOW will tri-state the
+5V
5
9
0.1µF
C1+
VCC
0.1µF
12
11
10
14
C1-
V+
V–
SP334
C2+
0.1µF
13
25
C2-
0.1µF
0V
RS232/RS485
Vcc
400KΩ
TX1
TX2
TX3
6
7
4
27 TI1
28 TI2
T1
T2
T3
TxD
RTS
DTR
Vcc
400KΩ
Vcc
400KΩ
1
DCD
1
TI3
DSR
6
RxD
RI1
RTS
TxD
CTS
DTR
RI
RxD
CTS
R1
R2
19 RX1
20 RX2
15
16
5KΩ
RI2
5KΩ
RI3
DSR
R3
R4
9
RX3
17
21
5KΩ
SG
RI4
DCD
RI
22 RX4
5KΩ
18
24
26
5
RI5
R5
RX5
23
8
5KΩ
GND
RXEN
Figure 18. SP334 Configuration to a DB-9 Serial Port
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
10
PACKAGE: 28-PIN PLASTIC
SMALL OUTLINE (SOIC)
E
H
D
A
Ø
A1
L
e
B
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
28–PIN
A
A1
B
D
E
0.093/0.104
(2.352/2.649)
0.004/0.012
(0.102/0.300)
0.013/0.020
(0.330/0.508)
0.698/0.706
(17.73/17.93)
0.291/0.299
(7.402/7.600)
e
0.050 BSC
(1.270 BSC)
H
L
0.394/0.419
(10.00/10.64)
0.016/0.050
(0.406/1.270)
Ø
0°/8°
(0°/8°)
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
11
ORDERING INFORMATION
Model
Temperature Range
Package Types
SP334CT ........................................................................... 0°C to +70°C .................................................................................. 28-pin Plastic SOIC
SP334ET ........................................................................ -40°C to +85°C .................................................................................. 28-pin Plastic SOIC
Please consult the factory for pricing and availability on a Tape-On-Reel option.
Co rp o ra tio n
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: sales@sipex.com
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.
SP334DS/10
Programmable RS-232/RS-485 Transceiver
© Copyright 2000 Sipex Corporation
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