SP485E(SP481E_SP485E).pdf

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SP481E/SP485E Enhanced Low Power Half-Duplex RS-485 Transceivers FEATURES ■ +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: NSOIC and PDIP RO 1 RE 2 DE 3 DI 4 R 8 VCC 7 B 6 A D SP485 5 GND Top View SP481E and SP485E Pinout (Top View) DESCRIPTION The SP481E and the 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 Sipex's SP481 and SP485 devices as well as popular industry standards. As with the original versions, the SP481E and the SP485E feature Sipex'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. RO 1 RE 2 DE 3 DI 4 R D 8 Vcc 7 B 6 A 5 GND SP481E and SP485E May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 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 Input Voltages Logic........................................................-0.3V to (VCC+0.5V) Drivers..................................................-0.3V to (VCC+0.5V) Receivers................................................................. ±15V TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted. Output Voltages Logic........................................................-0.3V to (VCC+0.5V) Drivers...................................................................... ±15V Receivers............................................-0.3V to (VCC+0.5V) Storage Temperature.......................................................-65˚C to +150˚C Power Dissipation per Package 8-pin NSOIC (derate 6.60mW/oC above +70oC)...........................550mW 8-pin PDIP (derate 11.8mW/oC above +70oC)............................1000mW ELECTRICAL CHARACTERISTICS MIN. TYP. MAX. UNITS CONDITIONS VCC VCC VCC Volts Volts Volts Unloaded; R = ∞ ; see Figure 1 with load; R = 50Ω; (RS-422); see Figure 1 with load; R = 27Ω; (RS-485);see Figure 1 0.2 Volts R = 27Ω or R = 50Ω; see Figure 1 3 0.8 ±10 Volts Volts Volts µA R = 27Ω or R = 50Ω; see Figure 1 Applies to DE, DI, RE Applies to DE, DI, RE Applies to DE, DI, RE ±250 mA ±250 mA -7V ≤ VO ≤ +12V -7V ≤ VO ≤ +12V Mbps ns ns ns ns ns ns ns ns ns ns 60 80 60 80 10 40 70 70 70 70 RE = 5V, DE = 5V; RDIFF = 54Ω, CL1 = CL2 = 100pF tPLH; RDIFF = 54Ω, CL1 = CL2 = 100pF; see Figures 3 and 5 tPLH; RDIFF = 54Ω, CLI = CL2 = 100pF; See Figures 3 and 5 tPHL; RDIFF = 54Ω, CL1 = CL2 = 100pF; see Figures 3 and 5 tPHL; RDIFF = 54Ω, CL1 = CL2 = 100pF; see Figures 3 and 5 see Figures 3 and 5, tSKEW = | tDPLH - tDPHL | From 10% to 90%; RDIFF = 54Ω, CL1 = CL2 = 100pF; see Figures 3 & 6 CL = 100pF; see Figures 4 & 6; S2 CL = 100pF; see Figures 4 & 6; S1 CL = 100pF; see Figures 4 & 6; S1 CL = 100pF; see Figures 4 & 6; S2 30 30 30 30 5 15 40 40 40 40 PARAMETERS SP481E/SP485E 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 SP481E/SP485E DRIVER AC Characteristics Maximum Data Rate Driver Input to Output Driver Input to Output (SP485EMN ONLY) Driver Input to Output Driver Input to Output (SP485EMN ONLY) Driver Skew GND 2 1.5 2.0 10 20 20 20 20 Driver Rise or Fall Time 3 Driver Enable to Output High closed Driver Enable to Output Low closed Driver Disable Time from Low closed Driver Disable Time from High closed May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 Sipex Corporation 2

TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted. MIN. ELECTRICAL CHARACTERISTICS TYP. MAX. UNITS CONDITIONS -0.2 -0.4 3.5 +0.2 Volts +0.4 Volts -7V ≤ VCM ≤ +12V -7V ≤ VCM ≤ +12V 20 mV Volts Volts VCM = 0V IO = -4mA, VID = +200mV IO = +4mA, VID = -200mV 0.4 12 15 ±1 µA kΩ +1.0 mA -0.8 mA 95 mA 0.4V ≤ VO ≤ 2.4V; RE = 5V -7V ≤ VCM ≤ +12V DE = 0V, VCC = 0V or 5.25V, VIN = 12V DE = 0V, VCC = 0V or 5.25V, VIN = -7V 0V ≤ VO ≤ VCC 45 45 13 45 45 45 45 Mbps ns 100 100 ns ns ns ns ns ns 70 70 70 70 = 100pF; Figures 3 & 7 RE = 0V, DE = 0V tPLH; RDIFF = 54Ω, CL1 = CL2 tPHL; RDIFF = 54Ω, = 100pF; Figures 3 & 7 CL1 = CL2 RDIFF = 54Ω; CL1 = CL2 = 100pF; Figures 3 & 7 CRL = 15pF; Figures 2 & 8; S1 closed CRL = 15pF; Figures 2 & 8; S2 closed CRL = 15pF; Figures 2 & 8; S1 closed CRL = 15pF; Figures 2 & 8; S2 closed 50 200 600 ns RE = 5V, DE = 0V 40 40 300 300 100 ns 100 ns 1000 ns 1000 ns CL = 100pF; See Figures 4 & 6; S2 closed CL = 100pF; See Figures 4 & 6; S1 closed CL = 15pF; See Figures 2 & 8; S2 closed CL = 15pF; See Figures 2 & 8; S1 closed +4.75 +5.25 Volts 7 10 20 20 PARAMETERS SP481E/SP485E RECEIVER DC Characteristics Differential Input Threshold Differential Input Threshold (SP485EMN ONLY) Input Hysteresis Output Voltage High Output Voltage Low Three-State (High Impedance) Output Current Input Resistance Input Current (A, B); VIN = 12V Input Current (A, B); VIN = -7V Short-Circuit Current SP481E/SP485E RECEIVER AC Characteristics Maximum Data Rate Receiver Input to Output Receiver Input to Output Diff. Receiver Skew ItPLH-tPHLI Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable from Low Receiver Disable from High SP481E Shutdown Timing Time to Shutdown 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 Supply Current SP481E/485E No Load SP481E Shutdown Mode ENVIRONMENTAL AND MECHANICAL Operating Temperature Commercial (_C_) Industrial (_E_) (_M_) Storage Temperature Package Plastic DIP (_P) NSOIC (_N) 0 -40 -40 -65 RE, DI = 0V or VCC; DE = VCC RE = 0V, DI = 0V or 5V; DE = 0V DE = 0V, RE=VCC 900 600 µA µA µA 10 +70 +85 +125 +150 °C °C °C °C May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 Sipex Corporation 3

RO 1 RE 2 DE 3 DI 4 R 8 VCC 7 B 6 A D SP485 5 GND Top View SP481E and SP485E Pinout (Top View) 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

INPUTS OUTPUTS INPUTS OUTPUTS RE DE DI CONDITION B 0 X X 1 Z X X Z No Fault No Fault 1 0 X X 1 1 0 1 LINE X Fault A 1 0 Z Z RE 0 0 0 1 DE 0 0 0 0 A - B +0.2V -0.2V Inputs Open X R 1 0 1 Z Table 2. Receive Function Truth Table Table 1. Transmit Function Truth Table DE A, B A, B +3V 0V 5V VOL VOH 0V f = 1MHz; tR < 10ns; tF < 10ns 1.5V tZL 2.3V 2.3V tZH Output normally LOW Output normally HIGH 1.5V tLZ 0.5V 0.5V tHZ Figure 6. Driver Enable and Disable Times A – B V0D2+ V0D2– R VOH VOL 0V INPUT 0V tPHL 1.5V OUTPUT tPLH f = 1MHz; tR < 10ns; tF < 10ns 1.5V tSKEW = | tPHL - tPLH | Figure 7. Receiver Propagation Delays RE +3V 0V R R 5V VIL VIH 0V 1.5V f = 1MHz; tR < 10ns; tF < 10ns tZL 1.5V Output normally LOW Output normally HIGH 1.5V tZH 1.5V tLZ 0.5V 0.5V tHZ Figure 8. Receiver Enable and Disable Times May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 Sipex Corporation 5

DESCRIPTION Receivers The SP481E and SP485E are half-duplex differ- ential transceivers that meet the requirements of RS-485 and RS-422. Fabricated with a Sipex proprietary BiCMOS process, all three products require a fraction of the power of older bipolar designs. 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. 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 54Ω across the differ- ential 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 DE (pin 3) will tri-state the driver outputs. The transmitters of the SP481E and SP485E will operate up to at least 10Mbps. The SP481E and SP485E receivers have differ- ential inputs with an input sensitivity as low as ±200mV. Input impedance of the receivers is typically 15kΩ (12kΩ minimum). A wide com- mon 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 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. Fail-safe guarantees that the receiver output will be in a HIGH state when the input is left unconnected. Shutdown Mode SP481E The SP481E 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 SP481E into Shutdown mode. In Shutdown, supply current will drop to typically 1µA. ESD TOLERANCE The SP481E 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 dis- charges 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 May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 Sipex Corporation 6

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. 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. There are two methods within IEC1000-4-2, the Air Discharge method and the Contact Discharge method. RC RRCC RS RRSS SW1 SW1SW1 SW2 SW2SW2 DC Power Source CS CCSS Device Under Test Figure 7. ESD Test Circuit for Human Body Model RC RRCC Contact-Discharge Module Contact-Discharge Module Contact-Discharge Module RS RRSS RV RRVV SW1 SW1SW1 SW2 SW2SW2 DC Power Source CS CCSS Device Under Test RS and RV add up to 330Ω for IEC1000-4-2. RRS S and add up to 330ΩΩ ffor IEC1000-4-2. or IEC1000-4-2. and RRV V add up to 330 Figure 8. ESD Test Circuit for IEC1000-4-2 May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 Sipex Corporation 7

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. 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. 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 switch (SW1) is on. Now that the capacitor is charged, the second switch (SW2) is on while SW1 switches off. The ➙ i 30A 15A 0A t=0ns t ➙ t=30ns Figure 9. ESD Test Waveform for IEC1000-4-2 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 1.5kΩ an 100pF, respectively. For IEC-1000-4- 2, the current limiting resistor (RS) and the source capacitor (CS) are 330Ω an 150pF, respectively. 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. SP481E, SP485E FAMILY HUMAN BODY MODEL Air Discharge Direct Contact Level IEC1000-4-2 Driver Outputs Receiver Inputs ±15kV ±15kV ±15kV ±8kV ±15kV ±8kV 4 4 May11-2007 SP481E Low Power Half-Duplex RS485 Transceivers © 2007 Sipex Corporation 8

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