View SP331CT_214105.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

(R)
SP331
Programmable RS-232/RS-485 Transceiver
s +5V Only Operation s Software Programmable RS-232 or RS-485 Selection s Four RS-232 Transceivers in RS-232 Mode s Two RS-485 Full-Duplex Transceivers in RS-485 Mode s Two RS-232 Transceivers and One RS-485 Transceiver in Dual Mode s Self-Testing Loopback Mode s Full Driver Tri-State (Hi-Z) Control s Ideal for RS-232 to RS-485 conversion
DESCRIPTION... The SP331 is a programmable RS-232 and/or RS-485 transceiver IC. The SP331 contains four drivers and four receivers when selected in RS-232 mode; and two drivers and two receivers when selected in RS-485 mode. The SP331 also contains a dual mode which has two RS-232 drivers/receivers plus one differential RS-485 driver/receiver. The RS-232 transceivers can typically operate at 230kbps while adhering to the RS-232 specifications. The RS-485 transceivers can operate up to 10Mbps while adhering to the RS-485 specifications. The SP331 includes a self-test loopback mode where the driver outputs are internally configured to the receiver inputs. This allows for easy diagnostic serial port testing without using an external loopback plug. The RS-232 and RS-485 drivers can be disabled (High-Z output) by controlling a set of four select pins.
TI4 SEL_B TX4 TX3 VCC TX1 TX2 GND C1+ V+ (VDD) C2+ C1- C2- V- (VSS)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15
TI3 TI2 TI1 SEL_C SEL_A SEL_D RX4 RX3 RX2 RX1 RI4 RI3 RI2 RI1
SP331
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 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. VCC...........................................................................+7V Storage Temperature..........................-65C to +150C Power Dissipation 28-pin Plastic DIP...........................1000mW 28-pin Plastic SOIC.......................1000mW Package Derating: 28-pin Plastic DIP oJA....................................................40 C/W 28-pin Plastic SOIC oJA....................................................40 C/W
SPECIFICATIONS
Typically 25C @ Vcc = +5V unless otherwise noted.
MIN. LOGIC INPUTS VIL VIH LOGIC OUTPUTS VOL VOH RS-232 DRIVER DC Characteristics HIGH Level Output LOW Level Output Open Circuit Voltage Short Circuit Current Power Off Impedance AC Characteristics Slew Rate Transition Time Maximum Data Rate Propagation Delay tPHL tPLH RS-232 RECEIVER DC Characteristics HIGH Threshold LOW Threshold Receiver Open Circuit Bias Input Impedance AC Characteristics Maximum Data Rate Propagation Delay tPHL tPLH RS-485 DRIVER DC Characteristics Open Circuit Voltage Differential Output 120
TYP.
MAX. 0.8
UNITS Volts Volts Volts Volts
CONDITIONS
2.0 0.4 2.4
IOUT= -3.2mA IOUT= 1.0mA
+5.0 -15.0 -15 300
+15 -5.0 +15 100
Volts Volts Volts mA V/s s kbps
RL=3k, VIN=0.8V RL=3k, VIN=2.0V VOUT = 0V Vcc = 0V, Vout = 2.0V RL=3k, CL= 50pF VCC = +5.0V, TA @ +25C RL=3k, CL=2500pF ; between 3V, TA @ +25C RL=3k, CL=2500pF Measured from 1.5V of VIN to 50% of VOUT; RL=3k
30 1.5 235 2 2 8 8
s s
0.8 3 120
1.7 1.2 5 235 0.25 0.25
3.0 +2.0 7
Volts Volts Volts k kbps
VIN = +15V to -15V
1 1
s s
Measured from 50% of VIN to 1.5V of VOUT.
1.5
6.0 5.0
Volts Volts
RL=54, CL=50pF
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
2
SPECIFICATIONS
Typically 25C @ Vcc = +5V unless otherwise noted.
MIN. RS-485 DRIVER Balance Common-Mode Output Output Current Short Circuit Current AC Characteristics Maximum Data Rate Output Transition Time Propagation Delay tPHL tPLH Driver Output Skew RS-485 RECEIVER DC Characteristics Inputs Common Mode Range Receiver Sensitivity Input Impedance AC Characteristics Maximum Data Rate Propagation Delay tPHL tPLH Differential Receiver Skew
TYP.
MAX. 0.2 3.0
UNITS Volts Volts mA mA Mbps ns ns ns ns
CONDITIONS |VT| - |VT| RL=54 Terminated in -7V to +10V RL=54 Rise/fall time, 10%-90% See Figures 2 & 4 RDIFF=54, CL1=CL2=100pF RDIFF=54, CL1=CL2=100pF per Figure 4, tSKEW = | tDPLH - tDPHL|
28.0
250
10 30 80 80 10 50 120 120 20
-7.0 12 10
0.2 15
+12.0 0.3
Volts Volts k Mbps
-7V VCM +12V -7V VCM +12V
130 130 10
200 200 20
ns ns ns
See Figures 2 & 6 RDIFF=54, CL1=CL2=100pF RDIFF=54, CL1=CL2=100pF tSKEW = | tPLH - tPHL |; RDIFF=54, CL1=CL2=100pF
ENABLE TIMING RS-485 Driver Enable Time Enable to Low Enable to High Disable Time Disable From Low Disable From High
90 90 80 80
150 150 120 120
ns ns ns ns
See Figures 3 & 5 CL=15pF, S1 Closed CL=15pF, S2 Closed See Figures 3 & 5 CL=15pF, S1 Closed CL=15pF, S2 Closed
POWER REQUIREMENTS Supply Voltage VCC Supply Current ICC No Load (Tx Disabled) No Load (RS-232 Mode) No Load (RS-485 Mode) ENVIRONMENTAL Operating Temperature Commercial (..C..) Industrial (..E..) Storage Temperature
+4.75 10 15 7
+5.25 15 30 20
Volts mA mA mA SEL_A SEL_D = "0001" SEL_A SEL_D = "0000" SEL_A SEL_D = "1100"
0 -40 -65
+70 +85 +150
C C C
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
3
RECEIVER INPUT GRAPH
RS-485 RECEIVER +1.0mA
-7V
-3V +6V +12V
-0.6mA
1 Unit Load Maximum Input Current versus Voltage
TEST CIRCUITS
A R VOD R B
Figure 1. Driver DC Test Load Circuit Figure 2. Driver/Receiver Timing Test Circuit
CL1 DI A B RL CL2 A RO B 15pF
VOC
Output Under Test
500 CL
S1
VCC
S2
Figure 3. Driver Timing Test Load #2 Circuit
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
4
SWITCHING WAVEFORMS
f 1MHz; tR 10ns; tF 10ns 1.5V 0V B DRIVER OUTPUT A tDPLH tDPHL VO 1/2VO tPLH tPHL 1/2VO 1.5V
+3V DRIVER INPUT
DIFFERENTIAL VO+ OUTPUT 0V VA - VB VO- tSKEW = |tDPLH - tDPHL|
Figure 4. Driver Propagation Delays
tR
tF
+3V DE 0V 5V A, B VOL VOH A, B 0V
f = 1MHz; tR < 10ns; tF < 10ns 1.5V tZL 2.3V Output normally LOW 1.5V tLZ 0.5V 0.5V tHZ
2.3V tZH
Output normally HIGH
Figure 5. Driver Enable and Disable Times
V0D2+ A-B V0D2-
f = 1MHz; tR 10ns; tF 10ns 0V INPUT 0V
VOH RECEIVER OUT VOL
1.5V tPHL
OUTPUT tPLH
1.5V
Figure 6. Receiver Propagation Delays
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
5
TTL Input
Driver Output
Figure 7. Typical RS-232 Driver Output
Figure 8. Typical RS-485 Driver Output
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
6
TI4 SEL_B TX4 TX3 VCC TX1 TX2 GND C1+ V+ (VDD) C2+ C1- C2- V- (VSS)
1 2 3 4 5 6 7 8 9 10 11 12 13 14
28 27 26 25 24 23 22 21 20 19 18 17 16 15
TI3 TI2 TI1 SEL_C SEL_A SEL_D RX4 RX3 RX2 RX1 RI4 RI3 RI2 RI1
SP331
Figure 9. SP331 Pinout
+5V 5 VCC
+5V 5 9
9 0.1F 0.1F 0V 0V TTL/CMOS
C1+
12 C111 C2+ 13 C224 SEL A 2 SEL B 26 TI1
SP331
Vcc
V+ V-
10 14
0.1F
C1+
VCC 10
0.1F
0.1F
0.1F
0.1F 23 SEL D TX1 6 TX2 7 TX3 4 0V
+5V +5V
12 C111 C2+ 13 C224 SEL A 2 SEL B
400K
SP331
V+ V14 0.1F
SEL D
23
0V RS-485 RS-485 RS-485
Vcc
400K
TX2 7 T1 TX1 6
Vcc
400K
T1 T2 T3
RS-232 RS-232
TTL/CMOS TTL/CMOS TTL/CMOS
26 TI1 27 TI2
Vcc
TTL/CMOS TTL/CMOS
27 TI2
Vcc
400K
400K
TX4 3 T3 TX3 4 RI2 16 R1
15K
28 TI3 1 TI4
28 TI3
Vcc
400K
RS-485 RS-485 RS-485 RS-485 RS-485
RS-232
TTL/CMOS TTL/CMOS
19 RX1 20 RX2
TTL/CMOS
1 TI4
T4
TX4 3
RS-232
TTL/CMOS
RI1 15
15K
RI4 18
TTL/CMOS
19 RX1 20 RX2 21 RX3
R1
5K
RI1 15 RI2 16
5K
21 RX3
RS-232 RS-232
TTL/CMOS 22 RX4
R3
15K
RI3 17
15K
TTL/CMOS TTL/CMOS
R2 R3
5K
TTL/CMOS
RI3 17
8 GND
SEL C
25
0V
RS-232 RS-232
TTL/CMOS
22 RX4 8
R4
5K
RI4 18
GND
SEL C
25 0V
Figure 10. Typical Operating Circuit
SP331DS/13 SP331 RS-232/RS-485 Serial Transceiver (c) Copyright 2000 Sipex Corporation
7
FUNCTION TABLE FOR SELECT PINS A
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
B
0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
C
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
D
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
MODE
RS-232 RS-232 RS-232 RS-232 RS-232/RS-485 RS-232/RS-485 RS-232/RS-485 RS-232/RS-485 RS-485/RS-232 RS-485/RS-232 RS-485/RS-232 RS-485/RS-232 RS-485 RS-485 RS-485 RS-485
FUNCTION
All four RS-232 drivers active All four RS-232 drivers tri-state All four RS-232 drivers tri-state RS-232 (4ch) Loopback T1 and T2 active RS-232; T3 tri-state RS-485 T1 and T2 tri-state RS-232; T3 active RS-485 T1 and T2 active RS-232; T3 tri-state RS-485 RS-232 (2ch) / RS-485 (1ch) Loopback T1 active RS-485; T2 and T3 active RS-232 T1 tr-state RS-485; T3 active RS-232; T4 active RS232 All RS-485 and RS-232 drivers tri-state RS-485 (1ch) / RS-232 (2ch) Loopback T1 and T3 active RS-485 T1 tri-state RS-485; T3 active RS-485 T1 active RS-485; T3 tri-state RS-485 RS-485 (2ch) Loopback
Table 1. Mode Function Table. (Refer to Control Logic Confirmations for Block Diagrams)
THEORY OF OPERATION The SP331 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. 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 15(a) shows the waveform found on the positive side of capcitor C2, and Figure 15(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. 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. 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 capacitor C 1 is switched to +5V and the negative side is connected to ground. Phase 3 -- 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. Phase 4 -- 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,
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
8
VCC = +5V
+5V C1
+ -
C4
+ - +
C2
+ - -
VDD Storage Capacitor VSS Storage Capacitor
simultaneously with this, the positive side of capacitor C1 is switched to +5V and the negative side is connected to ground, and the cycle begins again. Since both V+ and V- are separately generated from VCC in a no-load condition, V+ and V- 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. The clock rate for the charge pump typically operates at 15kHz. The external capacitors must be 0.1F 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 voltages must be no greater than l0V. The current drain for the 10V supplies is used for RS-232. For the RS-232 driver the current requirement will be 3.5mA per driver. The external power supplies should provide a power supply sequence of :+l0V, then +5V, followed by -l0V.
-5V
-5V
C3
Figure 11. Charge Pump Phase 1.
VCC = +5V
C4
+ - +
C1
+ -
C2
+ - -
VDD Storage Capacitor VSS Storage Capacitor
-10V
C3
Figure 12. Charge Pump Phase 2.
VCC = +5V
+5V C1
+ -
C4
+ - +
C2
+ - -
VDD Storage Capacitor VSS Storage Capacitor
-5V
-5V
C3
Figure 13. Charge Pump Phase 3.
VCC = +5V
+10V C1
+ -
C4
+ - +
C2
+ - -
VDD Storage Capacitor VSS Storage Capacitor
C3
Figure 14. Charge Pump Phase 4.
+10V a) C2+ GND GND b) C2-10V
Figure 15. Charge Pump Waveforms
SP331DS/13 SP331 RS-232/RS-485 Serial Transceiver (c) Copyright 2000 Sipex Corporation
9
Drivers The SP331 has four independent RS-232 singleended drivers and two differential RS-485 drivers. Control for the mode selection is done via a four-bit control word. The drivers are prearranged such that for each mode of 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 will change to support the requirements of clock, 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 100k will suffice. When in RS-232 mode, the single-ended RS232 drivers produce compliant RS-232E and ITU V.28 signals. Each of the four drivers output single-ended bipolar signals in access of 5V with a full load of 3k and 2500pF applied as specified. These drivers can also operate at least 120kbps. When programmed to RS-485 mode, the differential RS-485 drivers produce complaint RS485 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 54 between the driver's two output pins. The signal levels and drive capability of the RS485 drivers allow the drivers to also comply with RS-422 levels. The transmission rate for the differential drivers is 10Mbps. Receivers The SP331 has four single-ended receivers when programmed for RS-232 mode and two differential receivers when programmed for RS-485 mode. Control for the mode selection is done via a 4- bit control word, as in 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 100k 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 5k is internally connected, which will ensure a logic high output. 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 differential RS-485 receiver has an input impedance of 15k and a differential threshold of 200mV. Since the characteristics of an RS422 receiver are actually subsets of RS-485, the receivers for RS-422 requirements are identical to the RS-485 receivers. All of the differential receivers can receive data up to 10Mbps. Select Mode Pins Similar to our SP500 family of multiprotocol products, the SP331 has the ability to change the configuration of the drivers and receivers via a 4-bit switch. Referring to Table 1; RS-232 mode, RS-485 mode, or two different combinations of RS-232/RS-485 can be configured using the SEL_A and SEL_B pins. The drivers can be put into tri-state mode by using the SEL_C and SEL_D pins. All receivers remain active during any tri-state condition of the drivers. Loopback Mode Loopback is invoked by asserting "xx11" into the select pins. In RS-232/RS-485 or RS-485/ RS-232 loopback mode, the RS-232 driver outputs loop back into the RS-232 receiver inputs and the RS-485 differential driver loops back into the RS-485 receiver. During loopback, the driver outputs and receiver inputs are disconnected from the outside world. The driver outputs are in tri-state and the receiver inputs are disabled. The input impedance of the receivers during loopback is approximately 15k to ground.
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
10
SP331 CONTROL LOGIC CONFIGURATION (Refer to Table 1)
SEL A SEL B SEL C SEL D 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 0 1 0 1 0 1 1 0 1 0 0 0 1 0 0 1 1 0 1 0 1 1 0 0 1 1 0 1 1 1 1 0
26 TI1
T1
TX1 6 TX2 7 TX3 4
26 TI1
T1
TX1 6
26 TI1
TX2 7
TX1 6 T1 TX2 7
26 TI1
TX1 6 T1 TX2 7
27 TI2 28 TI3
T2 T3
27 TI2
T2
28 TI3
28 TI3 TX3 4 T3 TX4 3
T3
TX3 4 28 TI3 TX3 4 T3 TX4 3
1 TI4
T4
TX4 3
1 TI4
T4
TX4 3
19 RX1 20 RX2
R1
RI1 15
19 RX1
R1
RI1 15
19 RX1
RI2 16
RI1 15 R1 RI2 16
19 RX1
RI1 15 R1 RI2 16
R2 21 RX3 R3
RI2 16
20 RX2
R2
RI3 17
21 RX3 RI3 17 R3 RI4 18
21 RX3
R3
RI3 17 21 RX3 RI3 17 R3 RI4 18
22 RX4
R4
RI4 18
22 RX4
R4
RI4 18
SP331 LOOPBACK (Refer to Table 1)
SEL A SEL B SEL C SEL D 0 0 1 1 0 1 1 1 1 0 1 1 1 1 1 1
26 TI1
T1
TX1 6 TX2 7 TX3 4
26 TI1 27 TI2
T1
TX1 6 26 TI1 TX2 7 28 TI3 T1
TX1 6 TX2 7
26 TI1
TX1 6 T1 TX2 7
27 TI2 28 TI3
T2 T3
T2
28 TI3 1 TI4 T4 TX4 3
TX3 4 T3 TX4 3 1 TI4
T3
TX3 4 28 TI3 TX3 4 T3 TX4 3
T4
TX4 3
19 RX1 20 RX2
R1
RI1 15 RI2 16 RI3 17
19 RX1 20 RX2
R1
RI1 15 19 RX1 R1 RI2 16 21 RX3
RI1 15 RI2 16
19 RX1
RI1 15 R1 RI2 16
R2 R3
R2
21 RX3
21 RX3 22 RX4 R4 RI4 18
RI3 17 R3 RI4 18 22 RX4
R3
RI3 17 21 RX3 RI3 17 R3 RI4 18
R4
RI4 18
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
11
PACKAGE: 28-PIN PLASTIC SMALL OUTLINE (SOIC)
E
H
D A O e B A1 L
DIMENSIONS (Inches) Minimum/Maximum (mm) A A1 B D E e H L O
28-PIN 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) 0.050 BSC (1.270 BSC) 0.394/0.419 (10.00/10.64) 0.016/0.050 (0.406/1.270) 0/8 (0/8)
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
12
ORDERING INFORMATION
Model Temperature Range Package Types SP331CT ........................................................................... 0C to +70C .................................................................................. 28-pin Plastic SOIC SP331ET ........................................................................ -40C to +85C .................................................................................. 28-pin Plastic SOIC Please consult the factory for pricing and availability on a Tape-On-Reel option.
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: 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.
SP331DS/13
SP331 RS-232/RS-485 Serial Transceiver
(c) Copyright 2000 Sipex Corporation
13

▲Up To Search▲

Price & Availability of SP331CT

	To Download SP331CT Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .