Union Semiconductor, Inc. http://www.union-ic.com UM3483E, UM3486E 3.3V-Powered, ±15kV ESD-Protected, and Slew-Rate-Limited True RS-485 Transceivers General Description The UM3483E, UM3486E are +15 KV ESD protected, slew-rate limited, ultra lower differential line transceivers which provide full RS485 compatibility while operating from single 3.3V supply. Each part contains one driver and one receiver, which is designed for data transmission with extended common mode range (-7V to 12V). The UM3483E features slew-rate limited driver that minimizes EMI and reduces reflections caused by improperly terminated cables, allowing error-free data transmission at data rate up to 500kbps, while partially slew-rate limited UM3486E transmits up to 2.5Mbps. All devices feature enhanced electrostatic discharge (ESD) protection. All transmitter outputs and receiver inputs are protected to ±15kV using IEC 1000-4-2 Air-Gap Discharge and ±15kV using the Human Body Model. Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if both inputs are open, shorted or idle. Both parts have power up/down glitch free driver outputs permit live insertion or removal of transceiver from/to data bus. The CMOS design offers significant power savings without sacrificing ruggedness against overload or ESD damage. Typical quiescent current is only 500 μA while operating and 1 μA in shutdown. The UM3483E, UM3486E are fully specified over the commercial an extended industrial temperature range and are available in 8-pin and DIP packages. Applications Telecommunications Low-Power RS-485 Transceivers Integrated Services Digital Networks Transceivers for EMI-Sensitive Applications Packet Switching Features ESD Protection for RS-485 I/O Pins ±15kV—Human Body Model ±15kV—IEC 1000-4-2, Air-Gap Discharge Operate from a Single 3.3V supply Interoperable with +5V Logic Slew-Rate Limited for Errorless Data Transmission 1 μA Low-Current Shutdown Mode –7V to +12V Common-Mode Input Voltage Range Allows up to 256 Transceivers on the Bus Thermal Shutdown Current-Limiting for Driver Overload Protection Ordering Information PART TEMP. RANGE UM3483EESA -40°C to +85°C PIN-PACKAGE 8 SO UM3483EEPA -40°C to +85°C 8 Plastic DIP UM3486EESA -40°C to +85°C 8 SO UM3486EEPA -40°C to +85°C 8 Plastic DIP UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 1 of 12 Union Semiconductor, Inc. http://www.union-ic.com Selector Guide PART GUARANTEED SUPPLY DATA RATE VOLTAGE (Mbps) (V) NUMBER UM3483E 0.5 UM3486E 2.5 SLEW-RATE 3.0 to 3.6 LIMITED DRIVER/ SHUTDOWN ±15kV RECEIVER CURRENT ESD PIN COUNT ENABLE (µA) PROTECTION Yes Yes 1 Yes 8 Yes Yes 1 Yes 8 Absolute Maximum Ratings Supply Voltage (VCC) ..............................… … … ..................5V Control Input Voltage (/RE, D E) .............… … … .....-0.3V to 5V Driver Input Voltage (DI) ......................… … … .......-0.3V to 5V Driver Output Voltage (A, B).............… … … … … … -7V to 12V Receiver Input Voltage (A, B) ..........… … … ...… ......-7V to 12V Receiver Output Voltage (RO).… … … ...-0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70°C) 8-Pin Plastic D IP (derate 9.09mW /°C above +70°C)..727mW 8-Pin SO (derate 5.88mW /°C above +70°)… … … … .471mW Operating Temperature Ranges UM 348 _EE_ _............................… ..… … … ......-40°C to +85°C Storage Temperature Range ........… … … … ......-65°C to +160°C Lead Temperature (soldering, 10sec) ...… … .… ..............+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC Electrical Characteristics (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C) PARAMETER Differential Driver Output SYMBOL VOD CONDITIONS MIN RL = 54ȍ ҏ(RS-485), Figure 2 1.2 RL = 60ȍ ҏ(RS-485), VCC = 3.3V, Figure3 1.2 TYP MAX UNITS V Change in Magnitude of Driver Differential ¨VOD RL = 54ȍҏor 100ȍ, Figure 2 VOC RL = 54ȍҏor 100ȍ, Figure 2 ¨VOC RL = 54ȍor 100ȍ, Figure 2 Input High Voltage VIH DE, DI, /RE Input Low Voltage VIL DE, DI, /RE 0.8 V Logic Input Current IIN1 DE, DI, /RE f2 μA Input Current (A, B) IIN2 Output Voltage for Complementary Output 0.2 V States (Note 1) Driver Common-Mode Output Voltage 2 V Change in Magnitude of Common-Mode Output Voltage 0.2 V (Note 1) Receiver Differential Threshold Voltage 2.0 V DE = 0V, VIN = 12V 1.0 VCC = 0V or 3.6V VIN = -7V -0.8 -7VİVCMİ12V VTH -0.2 -0.05 mA V Receiver Input Hysteresis ¨VTH VCM = 0V Receiver Output High Voltage VOH IOUT = -1.5mA, VID = 200mV, Figure 4 Receiver Output Low Voltage VOL IOUT = 2.5mA, VID = 200mV, Figure 4 0.4 V IOZR VCC = 3.6V, 0VİVOUTİVCC f1 μA Receiver Input Resistance RIN -7VİVCMİ12V Supply Voltage Range VCC Three-State (High Impedance) Output Current at Receiver Supply Current Supply Current in Shutdown Mode ICC ISHDN Driver Short-Circuit Output Current IOSD Receiver Short-Circuit Output Current IOSR 20 mV VCC - 0.4 V 96 kȍ 3.0 3.6 No load, DE = VCC, /RE = 0V or VCC 0.6 1.2 DI = 0V or VCC DE = 0V, /RE = 0V 0.5 1.0 DE = 0V, /RE = VCC, DI = VCC or 0V ESD Protection for A, B UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 1.0 -250 VOUT = 12V 250 0VİVROİVCC f8 f60 ±15 ±15 mA μA VOUT = -7V Human Body Model IEC 1000-4-2 Air Discharge V mA mA kV Page 2 of 12 Union Semiconductor, Inc. http://www.union-ic.com Receiver Switching Characteristics—UM3483E (VCC = 3.3V, TA = +25°C) PARAMETER SYMBOL CONDITIONS Maximum Data Rate MIN TYP MAX 0.5 UNITS Mbps Driver Differential Output Delay tDD RL = 60ȍ, Figure 5 600 900 1400 ns Driver Differential Output Transition Time tTD RL = 60ȍ, Figure 5 400 740 1200 ns Driver Propagation Delay, Low-to-High Level tPLH RL = 27ȍ, Figure 6 700 930 1500 ns Driver Propagation Delay, High-to-Low Level tPHL RL = 27ȍ, Figure 6 700 930 1500 |tPLH - tPHL| Driver Propagation Delay Skew (Note 2) tPDS RL = 27ȍ, Figure 6 f50 Driver Output Enable Time to Low Level tPZL RL = 110ȍ, Figure 8 900 1300 Driver Output Enable Time to High Level tPZH RL = 110ȍ, Figure 7 600 800 ns Driver Output Disable Time from High Level tPHZ RL = 110ȍ, Figure 7 50 80 ns Driver Output Disable Time from Low Level tPLZ RL = 110ȍ, Figure 8 50 80 ns Driver Output Enable Time from Shutdown to Low Level tPSL RL = 110ȍ, Figure 8 1.9 2.7 μs Driver Output Enable Time from Shutdown to High Level tPSH RL = 110ȍ, Figure 7 2.2 3.0 μs ns ns DRIVER-OUTPUT ENABLE/DISABLE TIMES ns Receiver Switching Characteristics—UM3486E (VCC = 3.3V, TA = +25°C) PARAMETER SYMBOL CONDITIONS Maximum Data Rate MIN TYP MAX 2.5 UNITS Mbps Driver Differential Output Delay tDD RL = 60ȍ, Figure 5 20 42 70 ns Driver Differential Output Transition Time tTD RL = 60ȍ, Figure 5 15 28 60 ns Driver Propagation Delay, Low-to-High Level tPLH RL = 27ȍ, Figure 6 20 42 75 ns Driver Propagation Delay, High-to-Low Level tPHL RL = 27ȍ, Figure 6 20 42 75 ns |tPLH - tPHL| Driver Propagation Delay Skew (Note 2) tPDS RL = 27ȍ, Figure 6 f12 ns Driver Output Enable Time to Low Level tPZL RL = 110ȍ, Figure 18 52 100 ns Driver Output Enable Time to High Level tPZH RL = 110ȍ, Figure 7 52 100 ns Driver Output Disable Time from High Level tPHZ RL = 110ȍ, Figure 7 40 80 ns Driver Output Disable Time from Low Level tPLZ RL = 110ȍ, Figure 8 40 80 ns Driver Output Enable Time from Shutdown to Low Level tPSL RL = 110ȍ, Figure 8 700 1000 ns Driver Output Enable Time from Shutdown to High Level tPSH RL = 110ȍ, Figure 7 700 1000 ns -6 DRIVER-OUTPUT ENABLE/DISABLE TIMES UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 3 of 12 Union Semiconductor, Inc. http://www.union-ic.com Receiver Switching Characteristics (VCC = +3.3V, TA = +25°C.) PARAMETER Time to Shutdown Receiver Propagation Delay, Low-to-High Level Receiver Propagation Delay, High-to-Low Level |tPLH - tPHL| Receiver Propagation-Delay Skew Receiver-Output Enable Time to Low Level Receiver-Output Enable Time to High Level Receiver-Output Disable Time from High Level Receiver-Output Disable Time from Low Level Receiver-Output Enable Time from Shutdown to Low Level Receiver-Output Enable Time SYMBOL MIN TYP MAX UM3483E /UM3486E (Note 3) CONDITIONS 80 190 300 VID = 0 to 3.0V, CL = 15pF, Figure 9 25 62 90 UM3483E 25 75 120 VID = 0 to 3.0V, CL = 15pF, Figure 9 25 62 90 UM3483E 25 75 120 VID = 0 to 3.0V, CL = 15pF, Figure 9 6 ±10 UM3483E 12 ±20 25 50 ns 25 50 ns 25 45 ns 25 45 ns 720 1400 ns 720 1400 ns tSHDN tRPLH tRPHL tRPDS tPRZL tPRZH tPRHZ tPRLZ tPRSL tPRSH from Shutdown to High Level CL = 15pF, Figure 10, UM3483E /UM3486E CL = 15pF, Figure 10, UM3483E /UM3486E CL = 15pF, Figure 10, UM3483E /UM3486E CL = 15pF, Figure 10, UM3483E /UM3486E CL = 15pF, Figure 12, UM3483E /UM3486E CL = 15pF, Figure 10, UM3483E /UM3486E UNITS ns ns ns ns Note 1: ¨VOD and ¨VOC are the changes in VOD and VOC, respectively, when the DI input changes state. Note 2: Measured on |tPLH (Y) - tPHL (Y)| and |tPLH (Z) - tPHL (Z)|. Note 3: The transceivers are put into shutdown by bringing /RE high and DE low. If the inputs are in this state for less than 80ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section. Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 4 of 12 Union Semiconductor, Inc. http://www.union-ic.com Typical Operating Characteristics (continued) (VCC = 3.3V, TA = +25°C, unless otherwise noted.) UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 5 of 12 Union Semiconductor, Inc. http://www.union-ic.com Pin Description PIN NAME 1 RO 2 /RE FUNCTION Receiver Output. If A > B by -50mV, RO will be high; if A < B by 200mV, RO will be low. Receiver Output Enable. RO is enabled when RE is low; RO is high impedance when RE is high. If RE is high and DE is low, the device will enter a low-power shutdown mode. Driver Output Enable. The driver outputs are enabled by bringing DE high. They are high impedance 3 DE when DE is low. If /RE is high and DE is low, the device will enter a low-power shutdown mode. If the driver outputs are enabled, the parts function as line drivers. While they are high impedance, they function as line receivers if /RE is low. 4 DI 5 6 7 8 GND Driver Input. A low on DI forces output B high and output A low. Similarly, a high on DI forces output B low and output A high. Ground A Noninverting Receiver Input and Noninverting Driver Output B Inverting Receiver Input and Inverting Driver Output VCC Positive Supply: 3.0VİVCCİ3.6V Figure 1. UM3483E /UM3486E Pin Configuration and Typical Operating Circuit Figure 2. Driver VOD and VOC Figure 3. Driver VOD with Varying Common-Mode Voltage Figure 4. Receiver VOH and VOL UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 6 of 12 Union Semiconductor, Inc. http://www.union-ic.com Figure 5. Driver Differential Output Delay and Transition Times Figure 6. Driver Propagation Times Figure 7. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) Figure 8. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 7 of 12 Union Semiconductor, Inc. http://www.union-ic.com Figure 9. Receiver Propagation Delay Figure 10. Receiver Enable and Disable Times Note 4: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tr=6.0ns, ZO = 50Ù. Note 5: CL includes probe and stray capacitance. Function Tables Devices with Receiver/Driver Enable Table 1. Transmitting INPUTS Table 2. Receiving OUTPUTS MODE /RE DE DI B A X 1 1 0 0 1 0 0 1 1 0 Normal Normal X High-Z High-Z Normal X High-Z High-Z Shutdown X 0 1 UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 INPUTS OUTPUTS MODE /RE DE A, B RO 0 X ıҏ-0.05V Normal 0 X İҏ-0.2V 0 1 X Inputs Open 1 0 1 0 X High-Z Shutdown Normal Normal Page 8 of 12 Union Semiconductor, Inc. http://www.union-ic.com Applications Information The UM3483E /UM3486E are low-power transceivers for RS-485 communications. The UM3483E can transmit and receive at data rates up to 500kbps, and the UM3486E at up to 2.5Mbps. The UM3483E /UM3486E are half-duplex. Driver Enable (DE) and Receiver Enable (/RE) pins are included on the UM3483E/ UM3486E. When disabled, the driver and receiver outputs are high impedance. Reduced EMI and Reflections The UM3483E is slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 11 shows the output waveform of the slew-rate-limited UM3483E transmitting a 125kHz signal, as well as the Fourier analysis of that waveform. The high-frequency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced. Low-Power Shutdown Mode A low-power shutdown mode is initiated by bringing both /RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled (high impedance). In shutdown, the devices typically draw only 1μA of supply current. For these devices, the tPSH and tPSL enable times assume the part was in the low-power shutdown mode; the tPZH and tPZL enable times assume the receiver or driver was disabled, but the part was not shut down. Figure 11. Driver Output Waveform and FFT Plot of Figure 12. UM3483E Driver Propagation Delay UM3483E Transmitting a 125kHz Signal Figure 13. UM3483E Receiver Propagation Delay Figure 14. UM3483E System Differential Voltage at 125kHz Driving 4000 ft of Cable UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 9 of 12 Union Semiconductor, Inc. http://www.union-ic.com Driver Output Protection Excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics). In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively. Propagation Delay Figures 12 and 13 show the typical propagation delays. Skew time is simply the difference between the low-to-high and high-to-low propagation delay. Small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle). The receiver skew time, |tPRLH - tPRHL|, is under 10ns (20ns for the UM3483E). The driver skew times 12ns for the UM3486E, and typically under 50ns for the UM3483E. Line Length vs. Data Rate The RS-485 standard covers line lengths up to 4000 feet. Figure 13 shows the system differential voltage for parts driving 4000 feet of 26AWG twisted-pair wire at 125kHz into 120ȍ loads. ±15kV ESD Protection As with all Union devices, ESD-protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. The driver outputs and receiver inputs of the UM3483E family of devices have extra protection against static electricity. Union’s engineers have developed 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, Union’s E versions keep working without latchup or damage. ESD protection can be tested in various ways; the transmitter outputs and receiver inputs of this product family are characterized for protection to the following limits: 1) ±15kV using the Human Body Model 2) ±15kV using IEC 1000-4-2’s Air-Gap method. Human Body Model Figure 15a shows the Human Body Model and Figure 15b shows the current waveform it generates when discharged into a low impedance. This model consists of 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device through a 1.5kȍ ҏresistor. IEC 1000-4-2 The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically refer to integrated circuits. The UM3483E family devices help you design equipment that meets Level 4 (the highest level) of IEC 1000-4-2, without the need for additional ESD-protection components. The major difference between tests done using the Human Body Model and IEC 1000-4-2 is higher peak current in IEC 1000-4-2, because 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. Figure 16a shows the IEC 1000-4-2 model, and Figure 16b shows the current waveform for the ±8kV IEC 1000-4-2, Level 4 ESD contact-discharge test. The air-gap test involves approaching the device with a charged probe. UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 10 of 12 Union Semiconductor, Inc. http://www.union-ic.com Machine Model The Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resistance. Its objective is to emulate the stress caused when I/O pins are contacted by handling equipment during test and assembly. Of course, all pins require this protection, not just RS-485 inputs and outputs. Typical Applications The UM3483E, UM3486E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 1 shows typical network applications circuits. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible. The slew-rate-limited UM3483E and the partially slew-rate-limited UM3486E are more tolerant of imperfect termination. Figure 15a. Human Body ESD Test Model Figure 15b. Human Body Current Waveform Figure 16a. IEC 1000-4-2 ESD Test Model Figure 16b. IEC 1000-4-2 ESD Generator Current Waveform UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 11 of 12 Union Semiconductor, Inc. http://www.union-ic.com Package Information UM3483E,UM3486E Datasheet Rev.0.1, Dec.2005 Page 12 of 12