SP334 Programmable RS-232/RS-485 Transceiver * +5V Single Supply 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 TI3 TXEN(n/c) TX4(n/c) TX3 VCC TX1 TX2 GND C1+ V+ C2+ C1- C2- V- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SP334 28 27 26 25 24 23 22 21 20 19 18 17 16 15 TI2 TI1 RXEN RS232/RS485 RI5 RX5 RX4 RX3 RX2 RX1 RI4 RI3 RI2 RI1 (in RS-232 Mode) DESCRIPTION The SP334 is a programmable RS-232 and/or RS-485 transceiver IC. The SP334 contains three drivers and five receivers when selected in RS-232 mode; and two drivers and two receivers when selected in RS-485 mode. 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 RS-485 drivers can be disabled (High-Z output) by the TXEN enable pin. The RS-232 and RS-485 receiver outputs can be disabled by the RXEN pin. TYPICAL APPLICATIONS CIRCUIT +5V 9 0.1F 12 11 0.1F TTL/CMOS 13 2 5 VCC C1+ C1C2+ TTL/CMOS 14 0.1F Vcc 27 TI1 1 0.1F 10 TXEN TX2 7 T1 Vcc TTL/CMOS V- C2- 400K TTL/CMOS V+ SP334 TX4 3 400K TI3 TX1 6 T3 TX3 4 RI1 15 19 RX1 R1 15K RI2 16 15K TTL/CMOS TTL/CMOS RI4 18 21 RX3 R3 26 8 15K RI3 17 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 15K RXEN GND RS232/ RS485 25 +5V Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 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......................+/-30V @ 100mA Driver Outputs..................................................+/-15V Maximum Data Rate...........................8Mbps (note 1) Storage Temperature.......................-65C to +150C Power Dissipation 28-pin WSOIC...................................1000mW Package Derating: 28-pin WSOIC oJA................................................40 C/W Note 1: Exceeding the maximum data rate of 8Mbps at TA = 85C may permanently damage the device SPECIFICATIONS Limits are specified at TA = 25C and VCC = +5.0V unless otherwise noted. PARAMETER MIN. TYP. MAX. UNITS 0.8 Volts CONDITIONS Logic Inputs VIL VIH 2.0 Volts LOGIC OUTPUTS VOL 0.4 VOH 2.4 Output Tri-state Leakage 10 Volts IOUT = -3.2mA Volts IOUT = 1.0mA A 0.4V VOUT +2.4V RS-232 DRIVER DC Characteristics HIGH Level Output +5.0 +15.0 Volts RL = 3k, VIN = 0.8V LOW Level Output -15.0 -5.0 Volts RL = 3k, VIN = 2.0V -15 +15 Volts +/-100 mA Open Circuit Voltage Short Circuit Current Power Off Impedance 300 VOUT = 0V VCC = 0V, VOUT = +/-2.0V AC Characteristics Slew Rate Transistion Time Maximum Data Rate 120 30 V/s 1.56 s 235 kbps Propagation Delay tPHL 2 8 s Propagation Delay tPLH 2 8 s 1.7 3.0 Volts 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 RS-232 RECEIVER DC Characteristics HIGH Threshold LOW Threshold 0.8 1.2 3 5 Receiver Open Circuit Bias Input Impedance Volts +2.0 Volts 7 k VIN = +15V to -15V Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 SPECIFICATIONS Limits are specifed at TA = 25C and VCC = +5.0V unless otherwise PARAMETER MIN. TYP. 120 235 MAX. UNITS CONDITIONS RS-232 RECEIVER (continued) AC Characteristics Maximum Data Rate kbps Propagation Delay tPHL 0.25 1 s Propagation Delay tPLH 0.25 1 s Measured from 50% of VIN to 1.5V of VOUT 6.0 Volts 5.0 Volts RL = 54, CL = 50pF +/-0.2 Volts |VT| - |VT| 3.0 Volts RS-485 DRIVER DC Characteristics Open circuit Voltage Differential Output 1.5 Balance Common-Mode Output Output Current 28.0 Short Circuit Current +/-250 mA RL = 54 mA Terminated in -7V to +10V AC Characteristics Maximum Data Rate 10 Maximum Data Rate 8 Mbps RL = 54 Mbps RL = 54, TA = +85C, Note 1 Output Transition Time 30 ns Rise/Fall time, 10%-90% Propagation Delay tPHL 80 120 ns Propagation Delay tPLH 80 120 ns See Figures 3 & 5, RDIFF = 54, CL1 = CL2 = 100pF Driver Output Skew 5 20 ns Per Figure 5, tSKEW = |tDPHL - tDPLH| +12 Volts +/-0.2 Volts -7V VCM +12V k -7V VCM +12V RS-485 RECEIVER DC Characteristics Common Mode Range -7.0 Receiver Sensitivity Input Impedance 12 15 AC Characteristics Maximum Data Rate 10 Mbps Maximum Data Rate 8 Mbps Propagation Delay tPHL 130 200 ns TA = +85C, Note 1 Propagation Delay tPLH 130 200 ns Differential Receiver Skew 10 20 ns tSKEW = |tPHL - tPLH|, RDIFF = 54, CL1 = CL2 = 100pF, see Figure 8 Enable to LOW 100 150 ns CL = 15pF, S1 Closed Enable to HIGH 100 150 ns CL = 15pF, S2 Closed See Figures 3 & 7, RDIFF = 54, CL1 = CL2 = 100pF ENABLE TIMING RS-485 DRIVER Enable Time (see Figures 4 and 6) Note 1: Exceeding the maximum data rate of 8Mbps at TA = 85C may damage the device. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 SPECIFICATIONS Limits are specifed at TA = 25C and VCC = +5.0V unless otherwise PARAMETER MIN. TYP. MAX. UNITS CONDITIONS Disable from LOW 100 120 ns CL = 15pF, S1 Closed Disable from HIGH 100 120 ns CL = 15pF, S2 Closed Enable to LOW 100 150 ns CL = 15pF, S1 Closed Enable to HIGH 100 150 ns CL = 15pF, S2 Closed Disable from LOW 100 120 ns CL = 15pF, S1 Closed Disable from HIGH 100 120 ns CL = 15pF, S2 Closed +5.25 Volts RS-485 Driver Continued Disable Time (see Figures 4 and 6) RS-485 RECEIVER Enable Time (see Figures 2 and 8) Disable Time (see Figures 2 and 8) POWER REQUIREMENTS Supply Voltage VCC +4.75 Supply Current ICC No Load (TX Disabled) 12 20 mA TXEN = 0V No Load (RS-232 Mode) 20 50 mA RS232/RS485 = 0V No Load (RS-485 Mode) 15 50 mA RS232/RS485 = +5V ENVIRONMENTAL Operating Temperature Commercial (_C_) 0 70 C Industrial (_E_) -40 +85 C Storage Temperature -65 +150 C Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 RECEIVER INPUT GRAPH RS-485 RECEIVER +1.0mA -7V -3V +6V +12V 1 Unit Load Maximum Input Current Versus Voltage -0.6mA Test Circuits A R VOD R 1k S2 B Figure 1. Driver DC Test Load Circuit DI A B VCC S1 CRL VOC 1k Test Point Receiver Output CL1 RL CL2 A B Figure 2. Receiver Timing Test Load Circuit Output Under Test RO 15pF 500 S1 VCC CL S2 Figure 3. Driver/Receiver Timing Test Circuit Figure 4. Driver Timing Test Load #2 Circuit Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 SWITCHING WAVEFORMS DRIVER INPUT f 1MHz; t R 10ns; t F 10ns +3V 1.5V 0V DRIVER OUTPUT B 1.5V t PLH t PHL VO 1/2VO A 1/2VO t DPLH DIFFERENTIAL VO+ OUTPUT 0V VA - VB VO- t DPHL tF tR t SKEW = |t DPLH - t DPHL| Figure 5. Driver Propagation Delays TXEN A, B A, B f = 1MHz; t R < 10ns; t F < 10ns +3V 1.5V 0V 1.5V t ZL 5V 2.3V VOL VOH 2.3V 0V t LZ Output normally LOW 0.5V Output normally HIGH 0.5V t ZH t HZ Figure 6. Driver Enable and Disable Times A- B f = 1MHz; t R 10ns ; t F 10ns VOD2 + 0V VOD2 - VOH RECEIVER OUT VOL 0V INPUT 1.5V 1.5V OUTPUT t PHL t PLH Figure 7. Receiver Propagation Delays Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 RXEN +3V 1.5V f = 1MHz; t 10ns; t 10ns R F 0V RECEIVER OUT t ZL 5V 1.5V VIL VIH RECEIVER OUT 1.5V 0V 1.5V t LZ Output normally LOW 0.5V Output normally HIGH 0.5V t ZH t HZ t SKEW = | t PHL - t PLH| Figure 8. Receiver Enable and Disable Times TTL Input TTL INPUT Driver Output A Driver Output B DRIVER OUTPUT Differential Output VA - VB Figure 9. Typical RS-232 Driver Output TI3 TXEN(n/c) TX4(n/c) TX3 VCC TX1 TX2 GND C1+ V+ C2+ C1- C2- V- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SP334 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Figure 10. Typical RS-485 Driver Output TI2 TI1 RXEN RS232/RS485 RI5 RX5 RX4 RX3 RX2 RX1 RI4 RI3 RI2 RI1 (in RS-232 Mode) Figure 11. SP334 Pinout Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 +5V 9 0.1F 5 VCC C1+ 12 C111 C2+ 13 C2- 0.1F 25 0V SP334 V+ V- +5V 0.1F 10 14 9 0.1F 0.1F 11 0V RS232/RS485 0.1F Vcc 400K 27 TI1 TTL/CMOS Vcc T1 TX1 6 TX2 7 TX3 4 RS-232 TTL/CMOS RS-232 TTL/CMOS 13 2 28 TI2 Vcc C1- T2 N/C TTL/CMOS TTL/CMOS TTL/CMOS 2 3 19 RX1 20 RX2 21 RX3 R1 RI1 15 5K R2 RI2 16 RS-232 TTL/CMOS Vcc TTL/CMOS 22 RX4 23 RX5 TX1 6 RI3 17 R3 R4 R5 RI4 18 RS-232 TTL/CMOS RS-232 TTL/CMOS 19 RX1 21 RX3 T3 TX3 4 RI1 15 R1 15K RI2 16 RI4 18 R3 26 8 RS-232 5K 15K RI3 17 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 RS-485 15K RXEN RS232/ RS485 GND 25 +5V RS-485 MDDE RI5 24 RS-232 5K RXEN GND TX4 3 400K TI3 15K 5K 26 8 TX2 7 T1 RS-232 5K TTL/CMOS 0.1F N/C TTL/CMOS 14 TXEN 27 TI1 1 V- 0.1F 10 C2- Vcc T3 V+ SP334 C2+ 400K 1 TI3 TTL/CMOS VCC C1+ 400K 400K TTL/CMOS 12 5 0V RS-232 MODE Figure 12. Typical Operating Circuit 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. 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. Charge-Pump The charge pump is a Exar-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 capacitor C2, and Figure 17(b) shows the negative side of capacitor C2. There is a free-running oscillator that controls the four phases of the voltage shifting. A description of each phase follows. 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 1 -- VSS charge storage --During this phase of the clock cycle, the positive side of capacitors C1 and C2 are initially charged to +5V. C1+ is then switched to ground and charge on Phase 4 -- VDD transfer -- The fourth phase of the clock connects the negative terminal of C2 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 to ground and transfers the generated l0V across C2 to C4, the VDD storage capacitor. Again, 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. VCC = +5V +5V C1 + C2 - -5V 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. + - -5V C4 + - VDD Storage Capacitor - + VSS Storage Capacitor C3 Figure 13. Charge Pump Phase 1. VCC = +5V C4 C1 The clock rate for the charge pump typically operates at 15kHz. The external capacitors must be a minimum of 0.1F with a 16V breakdown rating. + C2 - + - + - VDD Storage Capacitor - + VSS Storage Capacitor C3 -10V Figure 14. Charge Pump Phase 2. VCC = +5V 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 C1 + C2 - -5V + - C4 + - VDD Storage Capacitor - + VSS Storage Capacitor C3 -5V Figure 15. Charge Pump Phase 3. VCC = +5V +10V C1 + - C2 + - C4 + - VDD Storage Capacitor - + VSS Storage Capacitor C3 Figure 16. Charge Pump Phase 4. +10V a) C2+ GND GND b) C2-10V Figure 17. Charge Pump Waveforms Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP334_100_090909 Drivers The SP334 has three independent RS-232 single-ended drivers and two differential RS485 drivers. Control for the mode selection is done by the RS232/RS485 select pin. The drivers are pre-arranged 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. 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 RS-422 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. 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 access of 5V with a full load of 3k and 2500pF applied as specified. These drivers can also operate at least 120kbps. 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 tristate the outputs. The drivers can only be tri-stated in RS-485 mode. The drivers are always active in RS-232 mode. 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 54 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. The Receiver outputs can also be tri-stated by the 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 of the receivers during tri-state is at least 12k. Receivers The SP334 has five single-ended receivers when programmed for RS-232 mode and two differential receivers when programmed for RS-485 mode. Applications The SP334 allows the user flexibility in having a RS-232 or RS-485 serial port without using two different discrete active IC's. 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 receiver inputs. 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 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com 10 SP334_100_090909 +5V 9 0.1F 0.1F 0V 12 C111 C2+ 13 C225 5 VCC C1+ SP334 V+ V- 10 0.1F 14 0.1F 0V RS232/RS485 Vcc 400K TxD 27 TI1 Vcc T1 TX1 6 TX2 7 400K RTS 28 TI2 Vcc T2 1 400K DTR 1 TI3 TX3 4 T3 DCD DSR RxD RxD CTS DSR 19 RX1 20 RX2 21 RX3 R1 R2 RI1 15 RTS RI2 16 CTS 5K TxD 5K DTR RI3 17 R3 RI 5K DCD RI 22 RX4 23 RX5 R4 R5 RI4 18 SG RI5 24 5 GND 9 5K 5K 26 8 6 RXEN 0V Figure 18. SP334 Configuration to a DB-9 Serial Port Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com 11 SP334_100_090909 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com 12 SP334_100_090909 ORDERING INFORMATION Model Temperature Range Package Types SP334CT-L........................................................................... 0C to +70C..............................................................................................28-pin WSOIC SP334CT-L/TR..................................................................... 0C to +70C..............................................................................................28-pin WSOIC SP334ET-L....................................................................... -40C to +85C.............................................................................................28-pin WSOIC SP334ET-L/TR................................................................. -40C to +85C.............................................................................................28-pin WSOIC Note: /TR = Tape and Reel revision history DATE REVISION DESCRIPTION 2000 SP334/10 Legacy Sipex Datasheet 09/09/09 1.0.0 Convert to Exar Format. Add typical application circuit to page 1 and Revision History table. Remove EOL part numbers and update ordering information per PDN 081126-01. Change revision to 1.0.0. Add Maximum Data Rate to Absolute Maximum Ratings. Add RS-485 Driver and Receiver data rate column for 8Mbps maximum at Tmax and add Note 1. Notice EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writting, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized ; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Copyright 2009 EXAR Corporation Datasheet August 2009 Send your Interface technical inquiry with technical details to: uarttechsupport@exar.com Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com 13 SP334_100_090909