SP1481E/SP1485E Enhanced Low Power Half-Duplex RS-485 Transceivers +5V Only Low Power BiCMOS Driver/Receiver Enable for Multi-Drop configurations Low Power Shutdown Mode (SP1481E) Enhanced ESD Specifications: +15KV Human Body Model +15KV IEC1000-4-2 Air Discharge +8KV IEC1000-4-2 Contact Discharge Now Available in Lead Free Packaging description The SP1481E and the SP1485E 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 SP1481E and the SP1485E feature Exar's BiCMOS design allowing low power operation without sacrificing performance. The SP1481E and SP1485E meet the requirements of the RS-485 and RS-422 protocols up to 20Mbps under load. The SP1481E is equipped with a low power Shutdown mode. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 ABSOLUTE MAXIMUM RATINGS Output Voltages Logic.............................................-0.3V to (VCC+0.5V) Drivers................................................................ 15V Receivers......................................-0.3V to (VCC+0.5V) Storage Temperature.....................................................-65C to +150C 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 Power Dissipation per Package 8-pin NSOIC (derate 6.60mW/oC above +70oC).........................550mW 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 = 5V 5% unless otherwise noted. PARAMETERS SP1481E/SP1485E driver DC Characteristics Differential Output Voltage Differential Output Voltage Differential Output Voltage Change in Magnitude of Driver Differential Output Voltage for Complimentary States Driver Common-Mode Output Voltage Input High Voltage Input Low Voltage Input Current Driver Short-Circuit Current VOUT = HIGH VOUT = LOW MIN.TYP. MAX. UNITSCONDITIONS 3.5 2 VCC VCC Volts Volts 1.5 VCC Volts Unloaded; R = ; see Figure 1 with load; R = 50; (RS-422); see Figure 1 with load; R = 27; (RS-485);see Figure 1 0.2 Volts R = 27 or R = 50; see Figure 1 3 0.8 10 Volts Volts Volts A R = 27 or R = 50; see Figure 1 Applies to DE, DI, RE Applies to DE, DI, RE Applies to DE, DI, RE 250 mA 7V VO +12V 250 mA 7V VO +12V 2.0 SP1481E/SP1485E driver AC Characteristics Maximum Data Rate 20 Mbps Driver Input to Output 20 30 ns Driver Input to Output (SP1485EMN ONLY) 20 40 ns Driver Input to Output 20 30 ns Driver Input to Output 20 40 ns (SP1485EMN ONLY) Driver Skew 3 5 ns Driver Rise or Fall Time 8 20 ns Driver Enable to Output High 40 70 ns Driver Enable to Output Low 40 70 ns Driver Disable Time from Low 40 70 ns Driver Disable Time from High 40 70 ns RE = 5V, DE = 5V; RDIFF = 54, CL1 = CL2 = 100pF tPLH; RDIFF = 54, CL1 = CL2 = 100pF; see Figures 3 and 5 tPLH; RDIFF = 54, CLI = CL2 = 100pF; See Figures 3 and 5 tPHL; RDIFF = 54, CL1 = CL2 = 100pF; see Figures 3 and 5 tPHL; RDIFF = 54, CL1 = CL2 = 100pF; see Figures 3 and 5 see Figures 3 and 5, tSKEW = | tPLH - tPHL | From 10% to 90%; RDIFF = 54, CL1 = CL2 = 100pF; see Figures 3 & 6 CL = 100pF; see Figures 4 & 6; S2 closed CL = 100pF; see Figures 4 & 6; S1 closed CL = 100pF; see Figures 4 & 6; S1 closed CL = 100pF; see Figures 4 & 6; S2 closed Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 SPECIFICATIONS (continued) TMIN to TMAX and VCC = 5V 5% unless otherwise noted PARAMETERS MIN.TYP. MAX. UNITSCONDITIONS Differential Input Threshold -0.2 +0.2 Volts 7V VCM +12V Differential Input Threshold -0.4 +0.4 Volts 7V VCM +12V mV VCM = 0V Volts IO = 4mA, VID = +200mV 0.4 Volts IO = +4mA, VID = 200mV 1 A 0.4V VO 2.4V; RE = 5V SP1481E/SP1485E RECEIVER DC Characteristics (SP1485EMN ONLY) Input Hysteresis Output Voltage High 20 3.5 Output Voltage Low Three-State (High Impedance) Output Current Input Resistance 12 15 k 7V VCM +12V 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 Mbps RE = 0V, DE = 0V Short-Circuit Current 7 SP1481E/SP1485E RECEIVER AC Characteristics Maximum Data Rate 20 Receiver Input to Output 25 70 ns Receiver Input to Output 25 70 ns Diff. Receiver Skew ItPLH-tPHLI 5 10 ns tPLH; RDIFF = 54, CL1 = CL2 = 100pF; Figures 3 & 7 tPHL; RDIFF = 54, CL1 = CL2 = 100pF; Figures 3 & 7 RDIFF = 54; CL1 = CL2 = 100pF; Figures 3 & 7 Receiver Enable to Output Low 45 70 ns CRL = 15pF; Figures 2 & 8; S1 closed 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 200 600 ns RE = 5V, DE = 0V 40 100 ns CL = 100pF; See Figures 4 & 6; S2 closed 40 100 ns CL = 100pF; See Figures 4 & 6; S1 closed 300 1000 ns CL = 15pF; See Figures 2 & 8; S2 closed 300 1000 ns CL = 15pF; See Figures 2 & 8; S1 closed +5.25 Volts Receiver Enable to SP1481E Shutdown Timing Time to Shutdown 50 Driver Enable from Shutdown to Output High Driver Enable from Shutdown to Output Low Receiver Enable from Shutdown to Output High Receiver Enable from Shutdown to Output Low POWER REQUIREMENTS Supply Voltage +4.75 Supply Current SP1481E/1485E No Load 900 A RE, DI = 0V or VCC; DE = VCC 600 A RE = 0V, DI = 0V or 5V; DE = 0V SP1481E Shutdown Mode 10 A DE = 0V, RE=VCC environmental and mechanical Operating Temperature Commercial (_C_) 0 +70 C Industrial (_E_) -40 +85 C (_M_) -40 +125 C Storage Temperature -65 +150 C Package NSOIC (_N) Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 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. SP1481E and SP1485E Pinout (Top View) A R VOD 1k VOC S2 B Figure 1. RS-485 Driver DC Test Load Circuit DI A CL1 A RDIFF B B CL2 VCC S1 CRL R 1k Test Point Receiver Output Figure 2. Receiver Timing Test Load Circuit Output Under Test CL RO 15pF S1 500 VCC S2 Figure 3. RS-485 Driver/Receiver Timing Test Circuit DI DRIVER OUTPUT f 1MHz; t R 1ns; t F 1ns +3V 1.5V 0V B A Figure 4. RS-485 Driver Timing Test Load #2 Circuit 1.5V t PLH t PHL VO 1/2VO 1/2VO DIFFERENTIAL VO+ OUTPUT 0V VA - VB VO- tR tF Figure 5. Driver Propagation Delays Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 INPUTS OUTPUTS RE DE DI LINE CONDITION X 1 1 No Fault 0 1 X 1 0 No Fault 1 0 X 0 X X Z Z X 1 X Fault Z Z B A INPUTS OUTPUTS RE DE A-B R 0 0 +0.2V 1 0 0 -0.2V 0 0 0 Inputs Open 1 1 0 X Z Table 2. Receive Function Truth Table Table 1. Transmit Function Truth Table DE A, B A, B f = 1MHz; t R < 1ns ; t F < 1ns +3V 1.5V 0V 1.5V t ZL 5V t LZ 2.3V VOL VOH 2.3V 0V 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 1ns; t 1ns 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 SP1481E-1485E_102_102710 DESCRIPTION A logic LOW on RE (pin 2) will enable the receiver, a logic HIGH on RE (pin 2) will disable the receiver. The SP1481E and SP1485E are half-duplex differential transceivers that meet the requirements of RS-485 and RS-422. Fabricated with a Exar proprietary BiCMOS process, these products require a fraction of the power of older bipolar designs. The receiver for the SP1481E and SP1485E will operate up to at least 20Mbps. The receiver for each of the two devices is equipped with the fail-safe feature. Fail-safe guarantees that the receiver output will be in a HIGH state when the input is left unconnected. 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. Shutdown Mode SP1481E The SP1481E is equipped with a Shutdown mode. To enable the Shutdown state, both the 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 SP1481E into Shutdown mode. In Shutdown, supply current will drop to typically 1A. Drivers ESD Tolerance The driver outputs of the SP1481E and SP1485E 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 SP1481E, and SP1485E 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 DE (pin 3) will tri-state the driver outputs. The SP1481E Family 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 nor latch-up. There are different methods of ESD testing applied: a) MIL-STD-883, Method 3015.7 b) IEC1000-4-2 Air-Discharge c) IEC1000-4-2 Direct Contact The transmitters of the SP1481E and SP1485E will operate up to at least 20Mbps. 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 7. 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. Receivers The SP1481E and SP1485E 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 SP1481E and SP1485E have a tri-state enable control pin. Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 There are two methods within IEC1000-4-2, the Air Discharge method and the Contact Discharge method. The IEC-1000-4-2, 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 IEC1000-4-2 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 IEC1000-4-2 is shown on Figure 8. R RSS R RC C SW2 SW2 SW1 SW1 Device Under Test C CSS DC Power Source Figure 7. ESD Test Circuit for Human Body Model Contact-Discharge Module R RSS R RC C RV SW2 SW2 SW1 SW1 DC Power Source Device Under Test C CSS RS and RV add up to 330W for for IEC1000-4-2. IEC1000-4-2. Figure 8. ESD Test Circuit for IEC1000-4-2 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 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 Figure 9. ESD Test Waveform for IEC1000-4-2 switch (SW1) is on. Now that the capacitor is charged, the second switch (SW2) is on while SW1 switches off. 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. 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. For the Human Body Model, the current limiting resistor (RS) and the source capacitor (CS) are 1.5k an 100pF, respectively. For IEC-1000-4-2, the current limiting resistor (RS) and the source capacitor (CS) are 330 an 150pF, respectively. The circuit model in Figures 7 and 8 represent the typical ESD testing circuit used for all three methods. The CS is initially charged with the DC power supply when the first Sp1481E, SP1485E Family Driver Outputs Receiver Inputs The higher CS value and lower RS value in the IEC1000-4-2 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. Human Body MODEL Air Discharge 15kV 15kV t=30ns t IEC1000-4-2 Direct Contact 15kV 8kV 15kV 8kV Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com Level 4 4 SP1481E-1485E_102_102710 Exar Corporation 48720 Kato Road, Fremont CA, 94538 * 510-668-7017 * www.exar.com SP1481E-1485E_102_102710 ordering information ModelTemperature RangePackage SP1481ECN-L.................................................... 0C to +70C................................................ 8-pin Narrow SOIC SP1481ECN-L/TR...............................................0C to +70C................................................ 8-pin Narrow SOIC SP1481EEN-L.................................................. .-40C to +85C.............................................. 8-pin Narrow SOIC SP1481EEN-L/TR............................................ .-40C to +85C.............................................. 8-pin Narrow SOIC SP1485ECN-L.................................................... 0C to +70C................................................ 8-pin Narrow SOIC SP1485ECN-L/TR.............................................. 0C to +70C................................................ 8-pin Narrow SOIC SP1485EEN-L...................................................-40C to +85C.............................................. 8-pin Narrow SOIC SP1485EEN-L/TR.............................................-40C to +85C.............................................. 8-pin Narrow SOIC SP1485EMN-L.................................................-40C to +125C............................................. 8-pin Narrow SOIC SP1485EMN-L/TR...........................................-40C to +125C............................................. 8-pin Narrow SOIC DATE REVISION DESCRIPTION 03/08/07 J 06/16/09 1.0.0 Convert to Exar format, update ordering information and change revision to 1.0.0 08/03/10 1.0.1 Remove SP1485EMN option. 10/27/10 1.0.2 Reactiviate SP1485EMN option per PCN # 07-0502-01 Legacy Sipex Datasheet 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 2010 EXAR Corporation Datasheet October 2010 For technical support please email Exar's Serial Technical Support group at: serialtechsupport@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 10 SP1481E-1485E_102_102710