SP481E / SP485E Enhanced Low Power Half-Duplex RS-485 Transceivers * +5V Only * Low Power BiCMOS * Driver / Receiver Enable for Multi-Drop configurations * Low Power Shutdown mode (SP481E) * Enhanced ESD Specifications: +/-15kV Human Body Model +/-15kV IEC1000-4-2 Air Discharge +/-8kV IEC1000-4-2 Contact Discharge * Available in RoHS Compliant, Lead Free Packaging. DESCRIPTION The SP481E and SP485E are a family of half-duplex transceivers that meet the specifications of RS-485 and RS-422 serial protocols with enhanced ESD performance. The ESD tolerance has been improved on these devices to over +15kV for both Human Body Model and IEC1000-4-2 Air Discharge Method. These devices are pin-to-pin compatible with Exar's SP481 and SP485 devices as well as popular industry standards. As with the original versions, the SP481E and SP485E feature Exar's BiCMOS design allowing low power operation without sacrificing performance. The SP481E and SP485E meet the requirements of the RS-485 and RS-422 protocols up to 10Mbps under load. The SP481E is equipped with a low power shutdown mode. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 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. Output Voltages Logic.........................-0.3V to (Vcc + 0.5V) Drivers.............................................+/-15V Receivers..................-0.3V to (Vcc + 0.5V) Storage Temperature.......................-65C to +150C Power Dissipation 8-pin NSOIC...................................................550mW (derate 6.60mW/C above +70C) 8-pin PDIP....................................................1000mW (derate 11.8mW/C above +70C) VCC.......................................................................+7V Input Voltages Logic.........................-0.3V to (Vcc + 0.5V) Drivers......................-0.3V to (Vcc + 0.5V) Receivers.........................................+/-15V ELECTRICAL CHARACTERISTICS TMIN to TMAX and VCC = +5.0V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP481E/SP485E DRIVER DC Characteristics Differential Output Voltage GND Vcc Volts Unloaded; R = ; see Figure 1 Differential Output Voltage 2 Vcc Volts With Load; R = 50 (RS-422); see Figure 1 Differential Output Voltage 1.5 Vcc Volts With Load; R = 27 (RS-485); see Figure 1 Change in Magnitude of Driver Differential Output Voltage for Complimentary states 0.2 Volts R = 27 or R = 50; see Figure 1 Driver Common Mode Output Voltage 3 Volts R = 27 or R = 50; see Figure 1 Volts Applies to DE, DI, RE Input High Voltage 2.0 Input Low Voltage 0.8 Volts Applies to DE, DI, RE +/-10 A Applies to DE, DI, RE VOUT = HIGH +/-250 mA -7V VO +12V VOUT = LOW +/-250 mA -7V VO +12V Input Current Driver Short Circuit Current SP481E/SP485E DRIVER AC Characteristics Max. Transmission Rate 10 Mbps RE = 5V, DE = 5V; RDIFF = 54, CL1 = CL2 = 100pF See Figures 3 & 5, RDIFF = 54, CL1 = CL2 = 100pF Driver Input to Output, tPLH 30 60 ns Driver Input to Output, tPLH (SP485EMN ONLY) 30 80 ns Driver Input to Output, tPHL 30 60 ns Driver Input to Output, tPHL (SP485EMN ONLY) 30 80 ns Driver Skew 5 10 ns see Figures 3 and 5, tSKEW = |tDPHL - tDPLH| Driver Rise or Fall Time 15 40 ns From 10%-90%; RDIFF = 54 CL1 = CL2 = 100pF; see Figures 3 and 6 See Figures 3 & 5, RDIFF = 54, CL1 = CL2 = 100pF Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 ELECTRICAL CHARACTERISTICS TMIN to TMAX and VCC = +5.0V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS Driver Enable to Output High 40 70 ns CL = 100pF, see Figures 4 and 6, S2 closed Driver Enable to Output Low 40 70 ns CL = 100pF, see Figures 4 and 6, S1 closed Driver Disable Time from High 40 70 ns CL = 100pF, see Figures 4 and 6, S2 closed Driver Disable Time from Low 40 70 ns CL = 100pF, see Figures 4 and 6, S1 closed SP481E/SP485E DRIVER (continued) AC Characteristics SP481E/SP485E RECEIVER DC Characteristics Differential Input Threshold -0.2 +0.2 Volts -7V VCM +12V Differential Input Threshold (SP485EMN ONLY) -0.4 +0.4 Volts -7V VCM +12V Input Hysteresis 20 Output Voltage High mV Volts IO = -4mA, VID = +200mV Output Voltage Low 0.4 Volts IO = +4mA, VID = +200mV Three-State ( High Impedance) Output Current +/-1 A 0.4V VO 2.4V; RE = 5V k -7V VCM +12V Input Resistance 3.5 VCM = 0V 12 15 Input Current (A, B); VIN = 12V +1.0 mA DE = 0V, VCC = 0V or 5.25V, VIN = 12V Input Current (A, B); VIN = -7V -0.8 mA DE = 0V, VCC = 0V or 5.25V, VIN = -7V 95 mA 0V VO VCC Short Circuit Current 7 SP481E/SP485E RECEIVER AC Characteristics Max. Transmission Rate 10 Receiver Input to Output 20 45 100 Mbps ns RE = 0V, DE = 0V tPLH ; See Figures 3 & 7, RDIFF = 54, CL1 = CL2 = 100pF Receiver Input to Output 20 45 100 ns tPHL ; See Figures 3 & 7, RDIFF = 54, CL1 = CL2 = 100pF ns RDIFF = 54, CL1 = CL2 = 100pF, see Figures 3 and 7 Differential Receiver Skew |tPHL - tPLH| 13 Receiver Enable to Output Low 45 70 ns CRL = 15pF, Figures 2 & 8; S1 Closed Receiver Enable to Output High 45 70 ns CRL = 15pF, Figures 2 & 8; S2 Closed Receiver Disable from LOW 45 70 ns CRL = 15pF, Figures 2 & 8; S1 Closed Receiver Disable from High 45 70 ns CRL = 15pF, Figures 2 & 8; S2 Closed Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 ELECTRICAL CHARACTERISTICS TMIN to TMAX and VCC = +5.0V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS 50 200 600 ns RE = 5V, DE = 0V Driver Enable from Shutdown to Output High 40 100 ns CL = 100pF; See Figures 4 and 6; S2 Closed Driver Enable from Shutdown to Output Low 40 100 ns CL = 100pF; See Figures 4 and 6; S1 Closed Receiver Enable from Shutdown to Output High 300 1000 ns CL = 15pF; See Figures 2 and 8; S2 Closed Receiver Enable from Shutdown to Output Low 300 1000 ns CL = 15pF; See Figures 2 and 8; S1 Closed +5.25 Volts SP481E Shutdown Timing Time to Shutdown POWER REQUIREMENTS Supply Voltage VCC +4.75 Supply Current SP481E/SP485E No Load 900 A RE, DI = 0V or VCC; DE = VCC 600 A RE = 0V, DI = 0V or 5V; DE = 0V 10 A DE = 0V, RE = VCC 70 C SP481E Shutdown Mode ENVIRONMENTAL AND MECHANICAL Operating Temperature Commercial (_C_) 0 Industrial (_E_) -40 +85 C (_M_) -40 +125 C Storage Temperature -65 +150 C Package Plastic DIP (_P) NSOIC (_N) Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 PIN FUNCTION Pin 1 - RO - Receiver Output Pin 2 - RE - Receiver Output Enable Active LOW Pin 3 - DE - Driver Output Enable Active HIGH Pin 4 DI - Driver Input Pin 5 - GND - Ground Connection Pin 6 - A - Driver Output / Receiver input Non-Inverting Pin 7 - B - Driver Output / Receiver Input Inverting Pin 8 - Vcc - Positive Supply 4.75V Vcc 5.25V Test Circuits A R VOD R 1k S2 B Figure 1. RS-485 Driver DC Test Load Circuit DI A B VCC S1 CRL VOC 1k Test Point Receiver Output CL1 A RL Output Under Test RO B CL2 Figure 2. Receiver Timing Test Load Circuit 15pF VCC S1 500 CL S2 Figure 3. RS-485 Driver/Receiver Timing Test Figure 4. Driver Timing Test Load #2 Circuit f 1MHz; t R 10ns; t F 10ns DRIVER INPUT +3V 1.5V 0V DRIVER OUTPUT B A 1.5V t PLH VO t PHL 1/2VO 1/2VO t DPLH DIFFERENTIAL VO+ 0V OUTPUT VA - VB VO- t DPHL tR tF t SKEW = |t DPLH - t DPHL | Figure 5. Driver Propagation Delays Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 Function Truth Tables INPUTS OUTPUTS INPUTS OUTPUTS RE DE DI LINE CONDITION RE DE A-B R X 1 1 No Fault 1 0 0 0 +0.2V 1 X 1 0 No Fault 0 1 0 0 -0.2V 0 X 0 X X Z Z 0 0 Inputs Open 1 X 1 X Fault Z Z 1 0 X Z A B Table 2. Receive Function Truth Table Table 1. Transmit Function Truth Table SWITCHING WAVEFORMS DE 1.5V 0V 1.5V t ZL 5V A, B A, B f = 1MHz; t R < 10ns; t F < 10ns +3V 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 R f = 1MHz; t R 10ns ; t F 10ns VOD2 + 0V VOD2 - VOH VOL 0V INPUT 1.5V 1.5V OUTPUT t PHL t PLH Figure 7. Receiver Propagation Delays RE R +3V 0V 5V VIL 1.5V f = 1MHz; t 10ns; t 10ns R F t ZL 1.5V VIH R 0V 1.5V 1.5V t LZ Output normally LOW 0.5V Output normally HIGH 0.5V t ZH t HZ Figure 8. Receiver Enable and Disable Times Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 DESCRIPTION Receivers The SP481E and SP485E are half-duplex differential transceivers that meet the requirements of RS-485 and RS-422. Fabricated with an Exar proprietary BiCMOS process, this product requires a fraction of the power of older bipolar designs. The SP481E and SP485E receivers have differential inputs with an input sensitivity as low as 200mV. Input impedance of the receivers is typically 15k (12k minimum). A wide common mode range of -7V to +12V allows for large ground potential differences between systems. The receivers of the SP481E and SP485E have a tri-state enable control pin. A logic LOW on RE (pin 2) will enable the receiver, a logic HIGH on RE (pin 2) will disable the receiver. 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 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 equipped with a wide (-7V to +12V) common mode range to accommodate ground potential differences. Because RS-485 is a differential interface, data is virtually immune to noise in the transmission line. The receiver for the SP481E and SP485E will operate up to at least 10Mbps. The receiver for each of the two devices is equipped with the fail-safe feature. Failsafe guarantees that the receiver output will be in a HIGH state when the input is left unconnected. Drivers The driver outputs of the SP481E and SP485E are differential outputs meeting the RS-485 and RS-422 standards. The typical voltage output swing with no load will be 0 Volts to +5 Volts. With worst case loading of 54 across the differential outputs, the drivers can maintain greater than 1.5V voltage levels. The drivers of the SP481E and SP485E have an enable control line which is active HIGH. A logic HIGH on DE (pin 3) will enable the differential driver outputs. A logic LOW on the DE(pin 3) will tri-state the driver outputs. Shutdown Mode SP481E The transmitters of the SP481E and SP485E will operate up to at least 10Mbps. The SP481E and SP485E incorporates ruggedized ESD cells on all driver output and receiver input pins. The ESD structure is improved over our previous family for more rugged applications and environments sensitive to electro-static discharges and associated transients. The improved ESD tolerance is at least 15kV without damage or latch-up. The SP481E is equipped with a Shutdown mode. TO enable the shutdown state, both driver and receiver must be disabled simultaneously. A logic LOW on DE (pin 3) and a Logic HIGH on RE (pin 2) will put the SP481E into Shutdown mode. In Shutdown, supply current will drop to typically 1A. ESD Tolerance There are different methods of ESD testing applied: a) MIL-STD-883, Method 3015.7 b) IEC61000-4-2 Air-Discharge c) IEC61000-4-2 Direct Contact Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 The Human Body Model has been the generally accepted ESD testing method for semiconductors. This method is also specified in MIL-STD-883, Method 3015.7 for ESD testing. The premise of this ESD test is to simulate the human body's potential to store electro-static energy and discharge it to an integrated circuit. The simulation is performed by using a test model as shown in Figure 9. This method will test the IC's capability to withstand an ESD transient during normal handling such as in manufacturing areas where the ICs tend to be handled frequently. The IEC-61000-4-2, formerly IEC801-2, is generally used for testing ESD on equipment and systems. For system manufacturers, they must guarantee a certain amount of ESD protection since the system itself is exposed to the outside environment and human presence. The premise with IEC61000-4-2 is that the system is required to withstand an amount of static electricity when ESD is applied to points and surfaces of the equipment that are accessible to personnel during normal usage. The transceiver IC receives most of the ESD current when the ESD source is applied to the connector pins. The test circuit for IEC61000-4-2 is shown on Figure 10. There are two methods within IEC61000-4-2, the Air Discharge method and the Contact Discharge method. RS RC SW1 SW2 Device Under Test CS DC Power Source Figure 9. ESD Test Circuit for Human Body Model Contact-Discharge Model RS RC RV SW1 SW2 Device Under Test CS DC Power Source R S and RV add up to 330 for IEC61000-4-2. Figure 10. ESD Test Circuit for IEC61000-4-2 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 I With the Air Discharge Method, an ESD voltage is applied to the equipment under test (EUT) through air. This simulates an electrically charged person ready to connect a cable onto the rear of the system only to find an unpleasant zap just before the person touches the back panel. The high energy potential on the person discharges through an arcing path to the rear panel of the system before he or she even touches the system. This energy, whether discharged directly or through air, is predominantly a function of the discharge current rather than the discharge voltage. Variables with an air discharge such as approach speed of the object carrying the ESD potential to the system and humidity will tend to change the discharge current. For example, the rise time of the discharge current varies with the approach speed. 30A 15A 0A t = 0ns The voltage stored in the capacitor is then applied through RS, the current limiting resistor, onto the device under test (DUT). In ESD tests, the SW2 switch is pulsed so that the device under test receives a duration of voltage. For the Human Body Model, the current limiting resistor (RS) and the source capacitor (CS) are 1.5k an 100pF, respectively. For IEC-61000-4-2, the current limiting resistor (RS) and the source capacitor (CS) are 330 an 150pF, respectively. The higher CS value and lower RS value in the IEC61000-4-2 model are more stringent than the Human Body Model. The larger storage capacitor injects a higher voltage to the test point when SW2 is switched on. The lower current limiting resistor increases the current charge onto the test point. The circuit model in Figures 9 and 10 represent the typical ESD testing circuit used for all three methods. The CS is initially charged with the DC power supply when the first switch (SW1) is on. Now that the capacitor is charged, the second switch (SW2) is on while SW1 switches off. Driver Outputs Receiver Inputs HUMAN BODY MODEL +/-15kV +/-15kV t = 30ns Figure 11. ESD Test Waveform for IEC61000-4-2 The Contact Discharge Method applies the ESD current directly to the EUT. This method was devised to reduce the unpredictability of the ESD arc. The discharge current rise time is constant since the energy is directly transferred without the air-gap arc. In situations such as hand held systems, the ESD charge can be directly discharged to the equipment from a person already holding the equipment. The current is transferred on to the keypad or the serial port of the equipment directly and then travels through the PCB and finally to the IC. SP481E, SP485E FAMILY t IEC61000-4-2 Air Discharge Direct Contact Level +/-15kV +/-15kV +/-8kV +/-8kV 4 4 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP481E,485E_103_052711 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com 10 SP481E,485E_103_052711 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com 11 SP481E,485E_103_052711 ORDERING INFORMATION Model Temperature Range Package Types SP481ECN-L........................................................................ 0C to +70C.................................................................................................8-pin NSOIC SP481ECN-L/TR.................................................................. 0C to +70C.................................................................................................8-pin NSOIC SP481EEN-L/.................................................................... -40C to +85C...............................................................................................8-pin NSOIC SP481EEN-L/TR................................................................. -40C to +85C.............................................................................................8-pin NSOIC SP485ECN-L........................................................................ 0C to +70C.................................................................................................8-pin NSOIC SP485ECN-L/TR.................................................................. 0C to +70C.................................................................................................8-pin NSOIC SP485ECP-L....................................................................... 0C to +70C.................................................................................................8-pin PDIP SP485EEN-L..................................................................... -40C to +85C................................................................................................8-pin NSOIC SP485EEN-L/TR................................................................ -40C to +85C...............................................................................................8-pin NSOIC SP485EEP-L...................................................................... -40C to +85C...............................................................................................8-pin PDIP SP485EMN-L..................................................................... -40C to +125C.............................................................................................8-pin NSOIC SP485EMN-L/TR............................................................... -40C to +125C.............................................................................................8-pin NSOIC Note: /TR = Tape and Reel revision history DATE REVISION May 11/07 -- DESCRIPTION 12/18/08 1.0.0 Convert to Exar Format. Update ordering information as a result of discontinued Lead type package options per PDN 081126-01. Remove "Top Mark" information from ordering page. Legacy Sipex Datasheet 11/19/09 1.0.1 Correct table 1 error for driver output A and B outputs 08/08/10 1.0.2 Change SP485EMN-L and SP485EMN-L/TR temperature range error from +85C to +125C in ordering information section. 05/27/11 1.0.3 Remove driver minimum limits of propagation delay and Rise/Fall time. Remove SP481ECP-L and SP481EEP-L per PDN 110510-01 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 2011 EXAR Corporation Datasheet May 2011 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 12 SP481E,485E_103_052711