SP3080EMN-L

S ol v e d by SP3080E TM Advanced-Failsafe RS-485/RS-422 Transceiver 1/8th Unit Load, Slew-Limited, ±15kV ESD-Protected FEATURES • 5.0V single supply operation • Receiver failsafe on open, short or terminated lines • 1/8th Unit Load, 256 transceivers on bus • Robust ESD protection for RS-485 pins o ±15kV Air-Gap Discharge o ±15kV Human Body Model o ±8kV Contact Discharge • Controlled driver slew rates o 115kbps, Low EMI •Hot Swap glitch protection on control inputs •Driver short circuit current limit and thermal shutdown for overload protection •Ultra-low 300µA quiescent current •650nA shutdown mode •Industry standard package footprints NC 1 RO 2 RE 3 DE 4 DI 5 GND 6 GND 7 14 Vcc 14 PIN NSOIC 13 NC 12 A 11 B 10 Z SP3080E Full Duplex 9Y 8 NC • Motor Control • Building Automation • Security Systems • Remote Meter Reading • Long or un-terminated transmission lines APPLICATIONS The SP3080E is designed for reliable, bidirectional communication on multipoint bus transmission lines. The device contains one differential driver and one differential receiver. The SP3080E is a full-duplex device. All devices comply with TIA/EIA-485 and TIA/EIA-422 standards. Lead-free and RoHS compliant packages are available for all models. This device is ruggedized for use in harsh operating conditions over the entire common-mode voltage range from -7V to +12V. The receiver is a specially designed to fail-safe to a logic high output state if the inputs are left un-driven or shorted. All RS-485 bus-pins are protected against severe ESD events up to ±15kV (Air-Gap and Human Body Model) and up to ±8kV Contact Discharge (IEC 1000-42). The driver is protected from excess current flow caused by bus contention or output short-circuits by both an internal current limit and a thermal-overload shutdown. The device is rated for industrial (-40 to +85ºC) or extended (-40 to +125ºC) operating temperatures. The receiver has exceptionally high input impedance, which places only 1/8th the standard load on a shared bus. Up to 256 transceivers may coexist while preserving full signal margin. The device operates from a single 5.0V power supply and draws negligible quiescent power. The SP3080E may independently enable and disable its driver and receiver and enter a low power shutdown mode if both driver and receiver are disabled. The output maintains high impedance in shutdown or when powered-off. Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver © Copyright 2006 Sipex Corporation DESCRIPTION 1 The device is available in industry standard architectures and footprints. DEVICE ARCHITECTURE AND BLOCK DIAGRAMS NC RO 1 2 R 3 RE DE 4 DI GND GND 5 6 7 D 14 VCC 13 NC 12 A 11 B 10 Z 14-Pin Full Duplex SP3080E, 115kbps slew limited 9Y 8 NC Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 2 © Copyright 2006 Sipex Corporation PIN ASSIGNMENTS Pin Number Pin Name Pin Function 2 RO Receiver Output. When RE is low and if (A – B) ≥ -40mV, RO is high. If (A – B) ≤ 200mV, RO is low. Receiver Output Enable. When RE is low, RO is enabled. When RE is high, RO is high impedance. Drive RE high and DE low to enter shutdown mode. RE is a hot-swap input. 3 RE 4 DE Driver Output Enable. When DE is high, outputs are enabled. When DE is low, outputs are high impedance. Drive DE low and RE high to enter shutdown mode. DE is a hotswap input. 5 DI Driver Input. With DE high, a low level on DI forces non-inverting output low and inverting output high. A high level on DI forces non-inverting output high and inverting output low. 6, 7 9 10 11 12 14 1, 8, 13 GND Y Z B A VCC NC Ground Non-inverting Driver Output Inverting Driver Output Inverting Receiver Input Non-inverting Receiver Input Positive Supply VCC. Bypass to GND with a 0.1uF capacitor. No Connect, not internally connected Note: On the 14-pin package connect both pins 6 and 7 to Ground. Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 3 © Copyright 2006 Sipex Corporation 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. Supply Voltage (VCC)...............................................+ 7.0V Input voltage at control input pins (RE, DE) ...... -0.3V to VCC+0.3V Driver input voltage (DI) .......................-0.3V to VCC+0.3V Driver output voltage (A, B, Y, and Z) ...................+/-13V Receiver input voltage (A, B) ................................+/-13V Package Power Dissipation: Maximum Junction Temperature 150°C 14-Pin SO øJA = 86°C/W Storage Temperature............................-65°C to +150°C Lead Temperature (soldering, 10s).................... +300°C RECOMMENDED OPERATING CONDITIONS Recommended Operating Conditions Supply Voltage, VCC Input Voltage on A and B pins High-level input voltage (DI, DE or RE), VIH Low-level input voltage (DI, DE or RE), VIL Driver Output Current Receiver Signaling Rate, 1/tUI Industrial Grade (E) Extended Temp Grade (M) -40 -40 -40 -8 8 115 85 °C 125 150 °C kbps Min. 4.5 -7 2 0 -60 Nom. 5 Max. 5.5 12 VCC 0.8 60 mA Unit V V V V Operating Free Air Temperature, TA Junction Temperature, TJ Note: The least positive (most negative) limit is designated as the maxium value. Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 4 © Copyright 2006 Sipex Corporation ELECTRICAL CHARACTERISTICS Unless otherwise stated, VCC=5V±10%, TAMB= TMIN to TMAX. Typical values at TAMB=25ºC PARAMETER Digital Input Signals: DI, DE, RE Logic input thresholds Logic Input Current Input Hysteresis Driver Differential Driver Output (VOD) Differential Driver Output, Test 1 Differential Driver Output, Test 2 Change in Magnitude of Differential Output Voltage (∆VOD) Note 1 Driver Common Mode Output Voltage (VCC) No Load RL=100Ω (RS-422), Figure 1 RL=54Ω (RS-485), Figure 1 Figure 3a, VCM = -7 to +12V RL=54 or 100Ω, Figure 1 RL=54 or 100Ω, Figure 1 -1 2 1.5 1.5 2.4 VCC VCC VCC VCC ±0.2 3 ±0.2 ±250 125 -100 µA V V V mA V V High, VIH Low, VIL TA = 25°C, after first transition, Note 4 TA = 25°C 100 2.0 0.8 ±1 V µA mV TEST CONDITIONS MIN TYP MAX UNIT Change in Common Mode Output Voltage (∆VOC) RL=54 or 100Ω, Figure 1 Driver Short Circuit Current Limit Output Leakage Current (Full-duplex versions, Y & Z pins) Receiver Receiver Input Resistance Input Current (A, B pins) Receiver Differential Threshold (VA-VB) Receiver Input Hysteresis Receiver VOH Output Voltage VOL High-Z Receiver Output Current Receiver Output Short Circuit Current Supply and Protection Supply Current IQ, Active Mode Shutdown Mode, Note 3 No load, DI=0 or VCC DE=0, RE=VCC, DI=VCC 300 0.650 IOUT = -8mA, VID = -40mV, Figure 2 IOUT = 8mA, VID = -200mV, Figure 2 VCC =5.5V, 0 ≤ VOUT ≤ VCC 0.0V ≤ VRO ≤ VCC VCC-1.5 7V ≤ VCM ≤ 12V DE=0, VCC=0 or 5.5V VIN= 12V VIN= -7V -100 -200 -110 25 96 -7V ≤ VOUT ≤ +12V DE=0, RE=0, VCC=0 or 5.5V VOUT=12V VOUT= -7V KΩ 125 µA -40 mV mV V 0.4 ±1 ± 95 µA mA -7V ≤ VCM ≤ 12V, Figure 2 900 1 µA µA Notes: 1. Change in Magnitude of Differential Output Voltage and Change in Magnitude of Common Mode Output Voltage are the changes in output voltage when DI input changes state. 3. The transceivers are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 50ns the device does not enter shutdown. If the enable inputs are held in this state for at least 600ns the device will be in shutdown. In this low power mode most circuitry is disabled and supply current is typically 650nA. 4.Hot-swap circuit adds pull-down resistance to first DE or RE transition. Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 5 © Copyright 2006 Sipex Corporation ELECTRICAL CHARACTERISTICS Unless otherwise stated, VCC=5V±10%, TAMB= TMIN to TMAX. Typical values at TAMB=25ºC PARAMETER Thermal Shutdown Temperature Thermal Shutdown Hysteresis IEC 1000-4-2 Air Discharge ESD Protection for A, B, Y, Z pins IEC 1000-4-2 Contact Human Body Model ESD Protection for RO, DI, DE, RE pins Human Body Model TEST CONDITIONS Junction temperature MIN TYP 165 15 ±15 ±8 ±15 ±2 kV MAX UNIT o C Notes: 1. Change in Magnitude of Differential Output Voltage and Change in Magnitude of Common Mode Output Voltage are the changes in output voltage when DI input changes state. 3. The transceivers are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 50ns the device does not enter shutdown. If the enable inputs are held in this state for at least 600ns the device will be in shutdown. In this low power mode most circuitry is disabled and supply current is typically 650nA. 4.Hot-swap circuit adds pull-down resistance to first DE or RE transition. TIMING CHARACTERISTICS Unless otherwise stated, VCC=5V±10%, TAMB= TMIN to TMAX. Typical values at TAMB=25ºC SP3080E DRIVER CHARACTERISTICS: Data Signaling Rate (1 / tUI) Driver Propagation Delay (tPHL, tPLH) Driver Output Rise/Fall Time (tR, tF) Driver Differential Skew (tPLH – tPHL) Driver Enable to Output High (tDZH) Driver Enable to Output Low (tDZL) Driver Disable from Output High (tDHZ) Driver Disable from Output Low (tDLZ) Shutdown to Driver Output Valid (tDZV) Figure 5 SP3080E Figure 4, 5 RL = 54Ω, CL = 50pF, Figure 3 Conditions Duty Cycle 40 to 60% Min. Typ. Max. Unit 115 500 1000 2600 667 800 2500 40 ±200 3500 3500 100 100 6000 Kbps ns ns ns ns ns ns ns ns Receiver CHARACTERISTICS: Receiver Prop. Delay Differential Receiver Skew Receiver Output Rise/Fall Time Receiver Enable to Output High (tZH) Receiver Enable to Output Low (tZL) Receiver Disable from High (tHZ) Receiver Disable from Low (tLZ) Shutdown to Receiver Output Valid (tROV) Time to Shutdown, Note 3,5 Conditions CL = 15pF, VID = ±2V, Figure 6 CL = 15pf Figure 7, 8 Figure 7, 8 Figure 7, 8 Figure 7, 8 Min. Typ. Max. Unit 90 6 200 ±30 15 20 16 20 18 50 50 50 50 3500 ns ns ns ns ns ns ns ns ns 50 200 600 Notes: 1. Change in Magnitude of Differential Output Voltage and Change in Magnitude of Common Mode Output Voltage are the changes in output voltage when DI input changes state. 3. The transceivers are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 50ns the device does not enter shutdown. If the enable inputs are held in this state for at least 600ns the device will be in shutdown. In this low power mode most circuitry is disabled and supply current is typically 650nA. 4.Hot-swap circuit adds pull-down resistance to first DE or RE transition. 5. Characterized, Not 100% tested Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 6 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS 350 700 No-load Supply Current (µA) 325 300 275 250 225 No-Load Supply Current (uA) 200 -60 -40 -20 0 20 40 60 80 100 Temperature (ºC) Shutdown Current (nA) DE = Vcc 650 DE = GND 600 Shutdown Current (nA) 550 500 -60 -40 -20 0 20 40 60 80 100 Temperature (ºC) No-load Supply Current vs Temperature Shutdown Current vs Temperature 0.35 IOUT=8mA, V ID=-200mV 0.3 4 IOUT=8mA, V ID=-40mV 3.9 Output Low Voltage (V) 0.25 Output High Voltage (V) -20 0 20 40 60 80 100 3.8 0.2 Output Low Voltage (V) 0.15 3.7 Output High Voltage (V) 3.6 0.1 -60 -40 Temperature (ºC) 3.5 -60 -40 -20 0 20 40 60 80 100 Temperature (ºC) Receiver Output Low Voltage vs Temperature Receiver Output High Voltage vs Temperature 120 CL=15pF, V ID=±2V Propagation Delay (ns) 110 100 90 Propagation Delay (ns) 80 70 -60 -40 -20 0 20 Temperature (ºC) 40 60 80 100 SP3080 Receiver Average Propagation Delay vs Temperature Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 7 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS 960 950 940 RL=54Ω CL=50pF R =50pF L L 120 CL=15pF, V ID=±2V 110 Propagation Delay (ns) 930 920 910 900 Propagation Delay (ns) 890 880 870 -60 -40 -20 0 20 Temperature (ºC) 40 60 80 100 tPHL tPLH Propagation Delay (ns) 100 tPHL 90 Propagation Delay (ns) 80 tPLH 70 -60 -40 -20 0 20 Temperature (ºC) 40 60 80 100 SP3080 Driver Propagation Delay vs Temperature SP3080 Receiver Propagation Delay vs Temperature 3.4 3.2 3 2.8 2.6 Output Voltage (V) 2.4 2.2 2 -60 -40 -20 0 20 40 60 80 100 Temperature (ºC) 1000 RLL R =100Ω Output Voltage (V) Supply Current (mA) 100 No Load VCC=5V TA=25ºC 50% Square wave input Driver and Receiver 10 RL=54Ω RL Supply Current (mA) 1 Receiver Only 0.1 1 10 Signaling Rate (kbps) 100 1000 Driver Differential Output Voltage vs Temperature SP3080 Supply Current vs Signaling Rate 60 35 30 50 Output Current (mA) Output Current (mA) 1 2 3 4 5 40 25 20 15 Output Current (mA) 10 5 0 0 1 2 3 4 5 Output High Voltage (V) 30 20 Output Current (mA) 10 0 0 Output Low Voltage (V) Output Current vs Receiver Low Voltage Output Current vs Receiver Output High Voltage Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 8 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS 100 90 80 -120 -100 Output Current (mA) 70 60 50 40 Output Current (mA) 30 20 10 0 0 1 2 3 4 5 6 Output Low Voltage (V) Output Current (mA) -80 -60 -40 Output Current (mA) -20 0 -2 -1 0 1 2 3 4 5 6 Output High Voltage (V) Output Current vs Driver Output Low Voltage Output Current vs Driver Output High Voltage 5 100 V CC =5V 90 80 70 RL=54Ω CL=50pF R =50pF L L Receiver Output Voltage (V) TA =25ºC 4 Skew (ns) -180 -160 -140 -120 -100 -80 -60 -40 -20 0 3 60 50 2 Skew (ns) 40 30 20 10 Receiver Output Voltage (V) 1 0 -200 Differential Input Voltage (mV) 0 -60 -40 -20 0 20 Temperature (ºC) 40 60 80 100 Receiver Output Voltage vs Differential Input Voltage Driver Differential Skew vs Temperature Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 9 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS SP3080 Driver and Receiver Waveform, Low to High SP3080 Driver and Receiver Waveform, High to Low SP3080 Driver output Waveform, Low to High SP3080 Driver output Waveform, High to Low SP3080 Driver Propagation Delay SP3080 Receiver Propagation Delay Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 10 © Copyright 2006 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS SP3080 Driver and Receiver Hot Swap Performance vs. Vcc Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 11 © Copyright 2006 Sipex Corporation DESCRIPTION R/2 DI VCC D VOD R/2 VOC A VID B R RE OUT Figure 1. Driver DC Test Circuit Figure 2. Receiver DC Test Circuit Y DI D Z RL 54Ω VOD CL 50pF 3.3V VCC DI 0 Z Y VO VDIFF -VO VCC/2 tPLH VO 1/2 VO 10% tR VDIFF = V(Y) - V(Z) 90% 90% 1/2 VO 10% tF tPHL VSKEW = tPLH - tPHL Figure 3. Driver Propagation Delay Time Test Circuit and Timing Diagram Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers © Copyright 2006 Sipex Corporation 12 DESCRIPTION DE= 3V A/Y DI= 0 or VCC D B/Z VOD 60 375 VCM 375 Figure 3a. Driver VOD Test 2 Driver Differential Output Test Circuit Y 0 or VCC DI D Z S1 OUT CL=50pF RL= 500Ω GENERATOR 50Ω VCC VCC /2 DE tZL, tZL(SHDN) 0.25V tLZ 0 VOM = (VOL + VCC)/2 OUT 0 Figure 4. Driver Enable and Disable Times Test Circuit and Timing Diagram Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver © Copyright 2006 Sipex Corporation 13 DESCRIPTION VCC Y 0 OR VCC DI D Z GENERATOR S1 RL=500Ω OUT CL=50pF 50Ω VCC VCC/2 DE VCC OUT VOM = (VOL+ VCC)/2 VOL tZL, tZL(SHDN) tLZ 0.25V 0 Figure 5. Driver Enable and Disable Times Test Circuit and Timing Diagram A VID OUT B R CL 15pF RE A B tPHL 1.5V OUT tPLH +1V -1V VOH VOL Figure 6. Receiver Propagation Delay Test Circuit and Timing Diagram Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers © Copyright 2006 Sipex Corporation 14 DESCRIPTION 1.5V -1.5V S3 B A RE 1KΩ S1 S2 VCC CL=15pF GENERATOR 50Ω Figure 7. Receiver Enable and Disable Times Test Circuit S1 is open, S2 is closed, S3=1.5V 3V S1 is closed, S2 is open, S3= -1.5V 3V 1.5V tZL, tZL(SHDN) RE 1.5V tZH, tZH(SHDN) VOH RE 0V OUT VOH/2 0V VCC OUT VOL = VCC/2 VOL S1 is open, S2 is closed, S3=1.5V RE 0.25V 1.5V S1 is closed, S2 is open, S3= -1.5V 3V RE 1.5V tLZ 0V VCC 3V VOH OUT 0V OUT 0.25V VOL Figure 8. Receiver Enable and DisableTiming Diagram Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 15 © Copyright 2006 Sipex Corporation FUNCTION TABLES SP3080E (Full Duplex) Transmitting Inputs RE X X 0 1 DE 1 1 0 0 DI 1 0 X X Y 1 0 High-Z Shutdown Outputs Z 0 1 RE 0 0 0 1 1 DE X X X 1 0 Receiving Inputs VA- VB ≥ -40mV ≤-200mV Open/shorted X X Output RO 1 0 1 High-Z Shutdown Note: Receiver inputs -200mV < VA - VB < -40mV, should be considered indeterminate PRODUCT SELECTOR GUIDE Part Number SP3080E Data Rate (Mbps) 0.115 Receiver & Trans on Bus Foot-print Driver Enable Yes 256 SN75180 pin-compatible upgrade from: MAX3080 Duplex Full Shut-down Yes Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 16 © Copyright 2006 Sipex Corporation DETAILED DESCRIPTION SP3080E is an advanced RS-485/RS-422 transceiver. It contains one driver and one receiver. The device features fail-safe circuitry that guarantees a logic-high receiver output when the receiver inputs are open or shorted, or when they are connected to a terminated transmission line with all drivers disabled. SP3080E also feature a hot-swap capability allowing live insertion without error data transfer. The SP3080E features reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission up to 115kbps. The SP3080E is a full duplex transceiver. The device operates from a single 5.0V supply. Driver is output short-circuit current lim ited. Thermal-shutdown circuitry protects driver against excessive power dissipation. When activated, the thermal-shutdown circuitry places the driver outputs into a high-impedance state. RECEIVER INPUT FILTERING SP3080E receiver incorporates input filtering in addition to input hysteresis. This filtering enhances noise immunity with differential signals that have very slow rise and fall times. Receiver propagation delay increases due to this filtering. ADVANCED FAIL SAFE Ordinary RS485 differential receivers will be in an indeterminate state whenever A - B is less than ±200mV. This situation can occur whenever the data bus is not being actively driven. The Advanced Failsafe feature of the SP3080E guarantees a logic-high receiver output if the receiver’s differential inputs are shorted, opencircuit, or if they are shunted by a termination resistor. The receiver thresholds of the SP3080E is very precise and offset by at least a 40mV noise margin from ground. This results in a logic-high receiver output at zero volts input differential while maintaining compliance with the EIA/TIA485 standard of ±200mV. HOT-SWAP CAPABILITY When a micro-processor or other logic device undergoes its power-up sequence its logicoutputs are typically at high impedance. In this Rev N 9/15/2006 state they are unable to drive the DE and RE signals to a defined logic level. During this period, noise, parasitic coupling or leakage from other devices could cause standard CMOS enable inputs to drift to an incorrect logic level. DESCRIPTION If circuit boards are inserted into an energized backplane (commonly called “live insertion” or “hot-swap”) power may be suddenly applied to all circuits. Without the hot-swap capability, this situation could improperly enable the transceiver’s driver or receiver, driving invalid data onto shared busses and possibly causing driver contention or device damage. The SP3080E contains a special poweronreset circuit that holds DE low and RE high for approximately 10 microseconds. After this initial power-up sequence the hot-swap circuit becomes transparent, allowing for normal, unskewed enable and disable timings. ±15KV ESD PROTECTION ESD-protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. The driver output and receiver inputs of the SP3080E have extra protection against static electricity. Sipex uses state of the art structures to protect these pins against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, the SP3080E keeps working without latch-up or damage. ESD protection can be tested in various ways. The transmitter outputs and receiver inputs of the SP3080E is characterized for protection to the following limits: ±15kV using the Human Body Model ±8kV using the Contact Discharge method specified in IEC 1000-4-2 ±15kV Air-gap SP3080E Advanced RS485 Transceiver 17 © Copyright 2006 Sipex Corporation ESD TEST CONDITIONS ESD performance depends on a variety of conditions. Contact Sipex for a reliability report that documents test setup, methodology and results. IEC 1000-4-2 The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment. However, it does not specifically refer to integrated circuits. The SP3080E helps you design equipment to meet IEC 1000-4-2, without sacrificing board space and cost for external ESD-protection components. The major difference between tests done using the Human Body Model and IEC 1000-4-2 is a higher peak current in IEC 1000-4-2 series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD withstand voltage measured to IEC 1000-4-2 is generally lower than that measured using the human body model. The air-gap test involves approaching the device with a charged probe. The contact discharge method connects the probe to the device before the probe is energized. MACHINE MODEL The machine model for ESD tests all pins using a 200pF storage capacitor and zero discharge resistance. The objective is to emulate the stress caused when I/O pins are contacted by handling equipment during test and assembly. 256 TRANSCEIVERS ON THE BUS The standard RS-485 receiver input impedance is 12kΩ (1 unit load). A standard driver can drive up to 32 unit loads. The SP3080E family of transceivers has only a 1/8th unit load receiver input impedance (96kΩ), thereby allowing eight times as many, up to 256, transceivers to be connected in parallel on a communication line. Any combination of these devices and other RS-485 transceivers up to a total of 32 unit loads may be connected to the line. LOW POWER SHUTDOWN MODE Low-power shutdown mode is initiated by bringing both RE high and DE low simultaneously. While in shutdown devices typically draw only 200nA of supply current. DE and RE may be tied together and driven by a single control signal. Devices are guaranteed not to enter shutdown if RE is high and DE is low for less than Rev N 9/15/2006 50ns. If the inputs are in this state for at least 600ns, the parts are shutdown. Enable times tZH and tZL apply when the part is not in low-power shutdown state. Enable times tZH(SHDN) and tZL(SHDN) apply when the parts are shut down. The drivers and receivers take longer to become enabled from low power shutdown mode tZL(SHDN) and tZL(SHDN) than from driver/receiver-disable mode (tZH, tZL). DRIVER OUTPUT PROTECTION Two mechanisms prevent excessive output current and power dissipation caused by faults or by bus contention. First, a driver-current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range. Second, a thermalshutdown circuit forces the driver outputs into a high-impedance state if junction temperature becomes excessive. LINE LENGTH, EMI, AND REFLECTIONS SP3080E feature controlled slew-rate driv ers that minimize EMI and reduce reflections caused by improperly terminated cables. SP3080E driver rise and fall times are limited to no faster than 667ns, allowing error-free data transmission up to 115kbps. The RS-485/RS-422 standard covers line lengths up to 4,000ft. Maximum achievable line length is a function of signal attenuation and noise. Use of slew-controlled drivers such as the SP3080E may help to reduce crosstalk interference and permit communication over longer transmission lines. Termination prevents reflections by eliminating the impedance mismatches on a transmission line. Line termination is typically used if rise and fall times are shorter than the round-trip signal propagation time. Slew-limited drivers may reduce or eliminate the need for cable termination in many applications. DESCRIPTION SP3080E Advanced RS485 Transceivers 18 © Copyright 2006 Sipex Corporation TYPICAL APPLICATIONS: DESCRIPTION Bi-Directional Full-Duplex Network Bi-Directional Full-Duplex Network Point to Multi-Point Repeater Po in t to Multi - poi n t with Repeater Repeater Repeater (optional) (optional) Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 19 © Copyright 2006 Sipex Corporation Rev N 9/15/2006 SP3080E Advanced RS485 Transceivers 20 © Copyright 2006 Sipex Corporation ORDERING INFORMATION Part number LEAD FREE Tape & Reel SP3080EEN SP3080EMN -L -L /TR /TR Temperature range From -40 to +850C From -40 to +125 C 0 Package Type 14 pin NSOIC 14 pin NSOIC All packages are available as lead free (RoHS compliant). To order add “-L” suffix to part number. For Tape and Reel add “/TR”. Reel quantity is 2,500 for NSOIC. Example: SP3080EEN-L/TR = lead free and Tape and Reel. SP3080EEN/TR = standard with Tape and Reel. Sipex Corporation Headquarters and Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Solved by Sipex TM Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Rev N 9/15/2006 SP3080E Advanced RS485 Transceiver 21 © Copyright 2006 Sipex Corporation