SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION OCT 2011 REV. 1.0.0 GENERAL DESCRIPTION FEATURES The SP339 is an advanced multiprotocol transceiver supporting RS-232, RS-485, and RS-422 serial standards in a 40 pin QFN package. Integrated cable termination and four configuration modes allow all three protocols to be used interchangeably over a single cable or connector with no additional switching components. Full operation requires only four external charge pump capacitors. The RS-485/422 modes feature one driver and one receiver (1TX/1RX) in both half and full duplex configurations. The RS-232 mode (3TX/5RX) provides full support of all eight signals commonly used with the DB9 RS-232 connector. A dedicated diagnostic loopback mode is also provided. The high speed drivers operate up to 20Mbps in RS485/422 modes, and up to 1Mbps in RS-232 mode. All drivers can be slew limited to 250kbps in any mode to minimize electromagnetic interference (EMI). All transmitter outputs and receiver inputs feature robust electrostatic discharge (ESD) protection to ±15kV Human Body Model (HBM) and ±8kV IEC61000-4-2 Contact. Each receiver output has full failsafe protection to avoid system lockup, oscillation, or indeterminate states by defaulting to logic-high output level when the inputs are open, shorted, or terminated but undriven. No external biasing resistors are required. The RS-232 receiver inputs include a 5kΩ pull-down to ground. The RS-485/422 receiver inputs are high impedance (>96kΩ when termination is disabled), allowing up to 256 devices on a single communication bus (1/8th unit load). The SP339E operates from a single power supply, either 3.3V or 5V, with low idle current (2mA typical in all modes). The shutdown mode consumes less than 10µA for low power standby operation. • Pin selectable Cable Termination • No external resistors required for RS-485/422 termination and biasing • 3.3V or 5V Single Supply Operation • Robust ESD Protection on bus pins ■ ±15kV Human Body Model (HBM) ■ ±8kV IEC 61000-4-2 (Contact) • Max Data Rate of 20Mbps in RS-485/422 Modes and up to 1Mbps in RS-232 Modes • Pin selectable 250kbps Slew Limiting • 3 Drivers, 5 Receivers RS-232/V.28 • 1 Driver, 1 Receiver RS-485/422 ■ Full and Half Duplex Configuration ■ 1/8th Unit Load, up to 256 receivers on bus • RS-485/422 Enhanced Failsafe for open, shorted, or terminated but idle inputs • Space saving 6mm x 6mm QFN-40 Package • Pin compatible with SP338E TYPICAL APPLICATIONS • Dual Protocol Serial Ports (RS-232 or RS-485/422) • Industrial Computers • Industrial and Process Control Equipment • Point-Of-Sale Equipment • Networking Equipment • HVAC Controls Equipment • Building Security and Automation Equipment ORDERING INFORMATION PART NUMBER PACKAGE OPERATING TEMPERATURE RANGE DEVICE STATUS SP339EER1-L 40-pin QFN -40°C to +85°C Active SP339EER1-L/TR 40-pin QFN -40°C to +85°C Active SP339ECR1-L 40-pin QFN 0°C to +70°C Active SP339ECR1-L/TR 40-pin QFN 0°C to +70°C Active Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 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 to the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability and cause permanent damage to the device. Supply Voltage VCC -0.3V to +6.0V Receiver Input Voltage (from Ground) ±20V Driver Output Voltage (from Ground) ±20V Short Circuit Duration, TX out to Ground Continuous -0.3V to VCC+0.5V Voltage at TTL Input Pins Storage Temperature Range -65°C to +150°C Lead Temperature (soldering, 10s) +300°C Power Dissipation 40-pin QFN (derate 17mW/°C above +70°C) 500mW CAUTION: ESD (ElectroStatic Discharge) sensitive device. Permanent damage may occur on unconnected devices subject to high energy electrostatic fields. Unused devices must be stored in conductive foam or shunts. Personnel should be properly grounded prior to handling this device. The protective foam should be discharged to the destination socket before devices are removed. ESD PROTECTION MIN. R1-R9 Tx Output & Rx Input Pins All Other Pins 2 TYP. MAX. UNITS ±15 kV Human Body Model (HBM) ±8 kV IEC 61000-4-2 (Contact) ±2 kV Human Body Model (HBM) SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 PIN DESCRIPTIONS BY MODE (MODE1, MODE0) Pin Name 1 L1 2 00, Figure 1 01, Figure 2 10, Figure 3 11, Figure 4 R1 Output 1 1 L2 R2 Output R1 Output R1 Output 3 L3 T1 Input T1 Input T1 Input 4 L4 T2 Input 5 L6 R3 Output 1 1 6 L7 T3 Input 7 L8 R4 Output 1 1 8 L9 R5 Output 1 1 9 VCC VCC 10 GND Ground 11 SLEW SLEW = VCC enables 250kbps slew limiting 12 DIR1 T1 Enable, R1 Disable 13 N/C 14 MODE0 0 1 0 1 15 MODE1 0 0 1 1 16 N/C 17 TERM 18 N/C This pin is not used and is disconnected internally 19 ENABLE ENABLE = VCC for operation, ENABLE = 0V for shutdown 20 VCC VCC T1 Enable This pin is not used and is disconnected internally This pin is not used and is disconnected internally Enables RS-485/422 receiver termination 3 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 PIN DESCRIPTIONS BY MODE (MODE1, MODE0) Pin Name 00, Figure 1 01, Figure 2 10, Figure 3 11, Figure 4 21 R9 R5 Input 22 R8 R4 Input 23 GND 24 R7 T3 Output 25 R6 R3 Input 26 GND 27 R4 T2 Output R1 Input B 28 R3 T1 Output R2 Input A 29 GND 30 R2 R2 Input R1 Input A, T1 Out A T1 Out A 31 R1 R1 Input R1 Input B, T1 Out B T1 Out B 32 VCC VCC 33 VSS VSS - Charge pump negative supply, 0.1µF from ground 34 C2- C2+ - Charge pump cap 2 negative lead 35 C1- C1- - Charge pump cap 1 negative lead 36 GND Ground 37 C1+ C1+ - Charge pump cap 1 positive lead, 0.1µF 38 VCC VCC 39 C2+ C2+ - Charge pump cap 2 positive lead, 0.1µF 40 VDD VDD - Charge pump positive supply, 0.1µF to ground Ground Ground Ground 4 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 ELECTRICAL CHARACTERISTICS UNLESS OTHERWISE NOTED: VCC = +3.3V ±5% or +5.0V ±5%, C1-C4 = 0.1µF; TA = TMIN to TMAX. Typical values are at VCC = 3.3V, TA = +25°C. SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DC CHARACTERISTICS ICC Supply Current (RS-232) 2 8 mA No load, idle inputs ICC Supply Current (RS-485) 2 8 mA No load, idle inputs ICC Vcc Shutdown Current 1 10 µA ENABLE = 0V TRANSMITTER and LOGIC INPUT PINS: Pins 3, 4, 6, 11, 12, 14, 15, 17-19 VIH Logic Input Voltage High 2.0 V VCC = 3.3V VIH Logic Input Voltage High 2.4 V VCC = 5.0V VIL Logic Input Voltage Low IIL 0.8 V Logic Input Leakage Current Low 1 µA IIH Logic Input Leakage Current High 1 µA IPD Logic Input Pull-down Current 50 µA VHYS Logic Input Hysteresis 200 Input Low (VIN = 0V) Input High (VIN = VCC), pins 3, 4 and 6 Input High (VIN = VCC), pins 11, 12, 14, 15, 17-19 mV RECEIVER OUTPUTS: Pins 1, 2, 5, 7, 8 VOH Receiver Output Voltage High VOL Receiver Output Voltage Low IOSS Receiver Output ShortCircuit Current IOZ Receiver Output Leakage Current V IOUT = -1.5mA 0.4 V IOUT = 2.5mA ±20 ±60 mA 0 ≤ VO ≤ VCC ±0.1 ±1 µA VCC-0.6 5 0 ≤ VO ≤ VCC, Receivers disabled SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 ELECTRICAL CHARACTERISTICS (Continued) UNLESS OTHERWISE NOTED: VCC = +3.3V ±5% or +5.0V ±5%, C1-C4 = 0.1µF; TA = TMIN to TMAX. Typical values are at VCC = 3.3V, TA = +25°C. SYMBOL PARAMETERS MIN. TYP. MAX. UNITS +15 V CONDITIONS SINGLE-ENDED RECEIVER INPUTS (RS-232) VIN Input Voltage Range VIL Input Threshold Low VIH Input Threshold High VHYS Input Hysteresis RIN Input Resistance -15 0.6 1.2 V VCC = 3.3V 0.8 1.5 V VCC = 5.0V 1.5 2.0 V VCC = 3.3V 1.8 2.4 V VCC = 5.0V 0.3 3 5 ±5.0 ±5.5 V kΩ -15V ≤ VIN ≤ +15V V Output loaded with 3kΩ to Gnd ±7.0 V No load output ±60 mA 7 SINGLE-ENDED DRIVER OUTPUTS (RS-232) VO Output Voltage Swing ISC Short Circuit Current ROFF Power Off Impedance 300 10M 6 Ω VO = 0V VCC = 0V, VO = ±2V SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION ELECTRICAL CHARACTERISTICS (Continued) UNLESS OTHERWISE NOTED: VCC = +3.3V ±5% or +5.0V ±5%, C1-C4 = 0.1µF; TA = TMIN to TMAX. Typical values are at VCC = 3.3V, TA = +25°C. SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DIFFERENTIAL RECEIVER INPUTS (RS-485 / RS-422) RIN Receiver Input Resistance VTH Receiver Differential Threshold Voltage ∆VTH 96 kΩ -200 Receiver Input Hysteresis -125 -50 TERM = 0V, -7V ≤ VIN ≤ +12V mV mV VCM = 0V 125 µA VIN = +12V -100 µA VIN = -7V 25 IIN Receiver Input Current RTERM Termination Resistance 100 120 155 Ω RTERM Termination Resistance 100 120 140 Ω 2 VCC V RL = 100Ω (RS-422), Figure 6 1.5 VCC V RL = 54Ω (RS-485), Figure 6 1.5 VCC V VCM = -7V, Figure 7 1.5 VCC V VCM = +12V, Figure 7 -0.2 +0.2 V RL = 54Ω or 100Ω, Figure 6 3 V RL = 54Ω or 100Ω, Figure 6 0.2 V RL = 54Ω or 100Ω, Figure 6 TERM = VCC, Figure 5 -7V ≤ VCM ≤ +12V TERM = VCC, Figure 5 VCM = 0V DIFFERENTIAL DRIVER OUTPUTS (RS-485 / RS-422) VOD Differential Driver Output ∆VOD Change In Magnitude of Differential Output Voltage VCM Driver CommonMode Output Voltage ∆VCM Change In Magnitude of Common Mode Output Voltage IOSD Driver Output Short Circuit Current ±250 mA -7V ≤ VO ≤ +12V, Figure 8 Driver Output Leakage Current ±100 µA DIR1 = 0V in Mode 11, or ENABLE = 0V, -7V ≤ VO ≤ +12V IO 7 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 TIMING CHARACTERISTICS UNLESS OTHERWISE NOTED: VCC = +3.3V ±5% or +5.0V ±5%, C1-C4 = 0.1µF; TA = TMIN to TMAX. Typical values are at VCC = 3.3V, TA = +25°C. SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS ALL MODES tENABLE tSHUTDOWN Enable from Shutdown 1000 ns Enable to Shutdown 1000 ns RS-232, DATA RATE = 250kbps (SLEW = Vcc), ONE TRANSMITTER SWITCHING Maximum Data Rate tRHL, tRLH ⏐tRHL-tRLH⏐ tDHL, tDLH ⏐tDHL-tDLH⏐ tSHL, tSLH tSHL, tSLH 250 kbps Receiver Propagation Delay 100 Receiver Propagation Delay Skew 100 Driver Propagation Delay Transition Region Slew Rate from +3.0V to -3.0V or -3.0V to +3.0V ns 1400 Driver Propagation Delay Skew Transition Region Slew Rate from +3.0V to -3.0V or -3.0V to +3.0V ns RL = 3kΩ, CL = 1000pF CL = 150pF, Figure 9 ns RL = 3kΩ, CL = 2500pF, 600 ns Figure 10 30 V/µs VCC = 3.3V, RL = 3kΩ to 7kΩ, 4 CL = 150pF to 2500pF, Figure 10 VCC = 3.3V, RL = 3kΩ to 7kΩ, 6 30 V/µs CL = 150pF to 2500pF, TA = 25°C, Figure 10 RS-232, DATA RATE = 1Mbps (SLEW = 0V), ONE TRANSMITTER SWITCHING Maximum Data Rate tRHL, tRLH ⏐tRHL-tRLH⏐ tDHL, tDLH ⏐tDHL-tDLH⏐ tSHL, tSLH tSHL, tSLH Mbps RL = 3kΩ, CL = 250pF 1 Receiver Propagation Delay 100 Receiver Propagation Delay Skew 100 Driver Propagation Delay 300 Driver Propagation Delay Skew Transition Region Slew Rate from +3.0V to -3.0V or -3.0V to +3.0V Transition Region Slew Rate from +3.0V to -3.0V or -3.0V to +3.0V ns 150 ns CL = 150pF, Figure 9 ns RL = 3kΩ, CL = 1000pF, ns Figure 10 VCC = 3.3V, RL = 3kΩ to 7kΩ, 15 150 V/µs CL = 150pF to 1000pF, Figure 10 VCC = 3.3V, RL = 3kΩ to 7kΩ, 24 150 V/µs CL = 150pF to 1000pF, TA = 25°C, Figure 10 8 SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION TIMING CHARACTERISTICS (Continued) UNLESS OTHERWISE NOTED: VCC = +3.3V ±5% or +5.0V ±5%, C1-C4 = 0.1µF; TA = TMIN to TMAX. Typical values are at VCC = 3.3V, TA = +25°C. SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS RS-485/RS-422, DATA RATE = 250kbps (SLEW = Vcc), ONE TRANSMITTER SWITCHING Maximum Data Rate tRPHL, tRPLH 250 Receiver Propagation Delay kbps 50 ⏐tRPHL-tRPLH⏐ Receiver Propagation Delay Skew tDPHL, tDPLH Driver Propagation Delay 500 ⏐tDPHL-tDPLH⏐ Driver Propagation Delay Skew tDR, tDF Driver Rise and Fall Time 300 650 150 ns 20 ns 1000 ns 100 ns 1200 ns tRZH, tRZL Receiver Output Enable Time 200 ns tRHZ, tRLZ Receiver Output Disable Time 200 ns tDZH, tDZL Driver Output Enable Time 1000 ns tDHZ, tDLZ Driver Output Disable Time 200 ns RL = 54Ω, CL = 50pF CL = 15pF, Figure 11 RL = 54Ω, CL = 50pF, Figure 12 Figure 13 Figure 14 RS-485/RS-422, DATA RATE = 20Mbps (SLEW = 0V), ONE TRANSMITTER SWITCHING Maximum Data Rate tRPHL, tRPLH Mbps RL = 54Ω, CL = 50pF 20 Receiver Propagation Delay 50 ⏐tRPHL-tRPLH⏐ Receiver Propagation Delay Skew tDPHL, tDPLH Driver Propagation Delay 30 ⏐tDPHL-tDPLH⏐ Driver Propagation Delay Skew tDR, tDF Driver Rise and Fall Time 10 150 ns 10 ns 100 ns 10 ns 20 ns tRZH, tRZL Receiver Output Enable Time 200 ns tRHZ, tRLZ Receiver Output Disable Time 200 ns tDZH, tDZL Driver Output Enable Time 200 ns tDHZ, tDLZ Driver Output Disable Time 200 ns 9 CL = 15pF, Figure 11 RL = 54Ω, CL = 50pF, Figure 12 Figure 13 Figure 14 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION BLOCK DIAGRAM BY MODE (MODE1, MODE0) FIGURE 1. MODE 00 - LOOPBACK 10 REV. 1.0.0 SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 2. MODE 01 - RS-232 11 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 3. MODE 10 - RS-485 HALF DUPLEX 12 REV. 1.0.0 SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 4. MODE 11 - RS-485/422 FULL DUPLEX 13 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION TEST FIXTURES FIGURE 5. RS-485/422 RECEIVER TERMINATION RESISTANCE FIGURE 6. RS-485/422 DIFFERENTIAL DRIVER OUTPUT VOLTAGE FIGURE 7. RS-485/422 DIFFERENTIAL DRIVER OUTPUT VOLTAGE OVER COMMON MODE 14 REV. 1.0.0 SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 8. RS-485/422 DRIVER OUTPUT SHORT CIRCUIT CURRENT FIGURE 9. RS-232 RECEIVER PROPAGATION DELAY 15 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 10. RS-232 DRIVER PROPAGATION DELAY FIGURE 11. RS-485/422 RECEIVER PROPAGATION DELAY 16 REV. 1.0.0 SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 12. RS-485/422 DRIVER PROPAGATION DELAY AND RISE/FALL TIMES FIGURE 13. RS-485/422 RECEIVER OUTPUT ENABLE/DISABLE TIMES 17 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION FIGURE 14. RS-485/422 DRIVER OUTPUT ENABLE/DISABLE TIMES 18 REV. 1.0.0 SP339E REV. 1.0.0 RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION PRODUCT SUMMARY The SP339 is an advanced multiprotocol transceiver supporting RS-232, RS-485, and RS-422 serial standards in a 40 pin QFN package. Integrated cable termination and four configuration modes allow all three protocols to be used interchangeably over a single cable or connector with no additional switching components. The RS485/422 modes feature one driver and one receiver (1TX/1RX) in both half and full duplex configurations. The RS-232 mode (3TX/5RX) provides full support of all eight signals commonly used with the DB9 RS-232 connector. A dedicated mode is also available for diagnostic loopback testing. INTERNALLY SWITCHED CABLE TERMINATION Enabling and disabling the RS-485/422 termination resistor is one of the largest challenges system designers face when sharing a single connector or pair of lines across multiple serial protocols. A termination resistor may be necessary for accurate RS-485/422 communication, but must be removed when the lines are used for RS-232. SP339E provides an elegant solution to this problem by integrating the termination resistor and switching control, and allowing it to be switched in and out of the circuit with a single pin. No external switching components are required. ENHANCED FAILSAFE Ordinary RS-485 differential receivers will be in an indeterminate state whenever the data bus is not being actively driven. The enhanced failsafe feature of the SP339E guarantees a logic-high receiver output when the receiver inputs are open, shorted, or terminated but idle/undriven. The enhanced failsafe interprets 0V differential as a logic high with a minimum 50mV noise margin, while maintaining compliance with the EIA/TIA485 standard of ±200mV. No external biasing resistors are required, further easing the usage of multiple protocols over a single connector. ±15kV ESD PROTECTION ESD protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. The bus pins (driver outputs and receiver inputs) have extra protection structures, which have been tested up to ±15kV without damage. These structures withstand high ESD in all states: normal operation, shutdown and powered down. ESD protection is be tested in various ways. Exar uses the following methods to qualify the protection structures designed into SP339E: ±15kV using the Human Body Model (HBM) ±-8kV using IEC 61000-4-2 Contact Discharge The IEC 61000-4-2 standard is more rigorous than HBM, resulting in lower voltage levels compared with HBM for the same level of ESD protection. Because IEC 61000-4-2 specifies a lower series resistance, the peak current is higher than HBM. The SP339E has passed both HBM and IEC 61000-4-2 testing without damage. ±20V FAULT TOLERANCE All bus pins on the SP339E are protected against direct shorts or long term faults, up to ±20V. This allows the part to interoperate with legacy systems using ±15V RS-232 logic levels without damage or failure. DIAGNOSTIC LOOPBACK MODE The SP339E includes a diagnostic digital loop back mode for system testing as shown in Figure 1. The loopback mode connects the TTL driver inputs to the TTL receiver outputs, bypassing the analog driver and receiver circuitry. The analog/bus pins are internally disconnected in this mode. 19 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION PACKAGE DRAWINGS FIGURE 15. QFN40 20 REV. 1.0.0 SP339E RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION REV. 1.0.0 REVISION HISTORY DATE REVISION October 2011 1.0.0 DESCRIPTION Production Release NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in 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 writing, 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 2011 EXAR Corporation Datasheet Oct 2011. For technical support please email Exar’s Serial Technical Support group at: [email protected]. Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. 21