XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS SEPT 2013 REV. 1.0.0 Y GENERAL DESCRIPTION FEATURES T The XR3070-78X family of high performance RS-485/  10% Higher SNR (Signal-to-Noise Ratio) 422 devices are designed for improved performance in compared to other RS-485 devices (1.65V vs. 1.5V) I noisy industrial environments and increased tolerance  ±18V Fault Tolerance on Analog Bus pins L to system faults.  Robust ESD (ElectroStatic Discharge) Protection: I The analog bus pins can withstand direct shorts up to ■ ±15kV IEC 61000-4-2 Air Gap Discharge B ±18V, and are protected against ESD events up to ■ ± 8kV IEC 61000-4-2 Contact Discharge ±15kV. The differential high output driver delivers 10% A ■ ±15kV Human Body Model higher SNR than standard RS-485/422 devices, afford- ■ ± 4kV Human Body Model on non-bus pins I ing additional noise margin or extended cable lengths.  +3.0V to +3.6V Operation (3.3V ± 10%) L The receivers include full fail-safe circuitry, guarantee-  300μA Idle Current, 1nA Shutdown Current E ing a logic-high receiver output when the receiver  Enhanced Receiver Fail-Safe Protection for Open, inputs are open, shorted, or undriven. The receiver R Shorted, or Terminated but Idle Data Lines input impedance is at minimum 96k (1/8 unit load), allowing up to 256 devices on the bus while preserving  Hot-Swap Glitch Protection on DE and RE Pins & the full signal margin.  Driver Short Circuit Current Limit and Thermal Shutdown for Overload Protection The drivers are protected by short circuit detection as E well as thermal shutdown, and maintain high imped-  1/8th Unit Load Allows up to 256 Devices on Bus ance in shutdown or when powered off. The XR3070-  Industry Standard 8 and 14 NSOIC Packages C 75X drivers are slew limited for reduced EMI and error- N free communication over long or unterminated data cables. E The devices with DE and RE pins include hot swap cir- L cuitry to prevent false transitions on the bus during L powerup or live insertion, and can enter a 1nA low cur- rent shutdown mode for extreme power savings. E The transceivers draw less than 600μA from a +3.3V C supply, and typically only 300μA when idling with the X receivers active. E : TYPICAL APPLICATIONS S RO 1 R 8 V  Motor Control CC E RE 2 7 B  Security Systems I DE 3 6 A  Building and Process Automation R DI 4 D 5 GND  Remote Utility Meter Reading  Energy Monitoring and Control E  Long or Unterminated Transmission Lines S X Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 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 to the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability and cause permanent damage to the device. V -0.3V to +7.0V CC Input Voltage at Control and Driver Input (RE, DE, and DI) -0.3V to +7.0V Receiver Output Voltage (RO) -0.3V to (VCC + 0.3V) Driver Output Voltage (A, B, Y and Z) ±18V Receiver Input Voltage (A and B, half or full duplex) ±18V Transient Voltage Pulse, through 100 ±70V Driver Output Current ±250mA Storage Temperature Range -65°C to +150°C Lead Temperature (soldering, 10s) +300°C Package Power Dissipation 8-Pin SO JA = 128.4°C/W Maximum Junction Temperature = +150°C 14-Pin SO  = 86°C/W JA CAUTION: ESD (Electrostatic Discharge) sensitive device. Permanent damage may occur on unconnected devices subject to high energy electrostatic fields. Unused devices must be stored in conductive foam or shunts. Personnel should be properly grounded prior to handling this device. The protective foam should be discharged to the destination socket before devices are removed. ORDERING INFORMATION PART NUMBER DUPLEX DATA RATE PACKAGE TEMPERATURE RANGE XR3070XID-F Full 250kbps 14-pin Narrow SOIC -40°C to +85°C XR3071XID-F Full 250kbps 8-pin Narrow SOIC -40°C to +85°C XR3072XID-F Half 250kbps 8-pin Narrow SOIC -40°C to +85°C XR3073XID-F Full 1Mbps 14-pin Narrow SOIC -40°C to +85°C XR3074XID-F Full 1Mbps 8-pin Narrow SOIC -40°C to +85°C XR3075XID-F Half 1Mbps 8-pin Narrow SOIC -40°C to +85°C XR3076XID-F Full 20Mbps 14-pin Narrow SOIC -40°C to +85°C XR3077XID-F Full 20Mbps 8-pin Narrow SOIC -40°C to +85°C XR3078XID-F Half 20Mbps 8-pin Narrow SOIC -40°C to +85°C NOTE: Tape and Reel part numbers are XR30xxXIDTR-F, -F = Green / RoHS Compliant 2

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS ELECTRICAL CHARACTERISTICS Unless otherwise noted: V = +3.3V ±10%, T = T to T . Typical values are at V = 3.3V, T = +25°C. CC A MIN MAX CC A SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER DC CHARACTERISTICS VCC Supply Voltage Range 3.0 3.6 V 3 VCC V No Load 2 VCC V RL = 100 (RS-422), Figure 3 VOD Differential Driver Output 1.65 VCC V RL = 54 (RS-485), Figure 3 1.5 VCC V -7V  VCM  +12V, Figure 4 Change in Magnitude of VOD ±0.2 V Differential Output Voltage R = 100 (RS-422), or Driver Common-Mode Output L VCM Voltage (steady state) VCC / 2 3 V RL = 54 (RS-485), Figure 3, Note 1 Change in Magnitude of VCM ±0.2 V Common-Mode Output Voltage VIH 2.0 V Logic Input High Logic Input Thresholds (DI, DE, RE) VIL 0.8 V Logic Input Low VHYS Input Hysteresis (DI, DE, RE) 100 mV 0V  V  V , IIN Logic Input Current (DI, DE, RE) ±1 μA IN CC After first transition, Note 2 Logic Input Current (DE and RE) 100 ±200 μA Until first transition, Note 2 V = +12V, DE = 0V, OUT 125 μA V = 0V or 5.5V CC IA, B Input Current (A and B) V = -7V, DE = 0V, OUT -100 μA V = 0V or 5.5V CC V = +12V, DE = 0V, OUT 125 μA Output Leakage (Y and Z) VCC = 0V or 5.5V I OL Full Duplex (Note 2) V = -7V, DE = 0V, OUT -100 μA V = 0V or 5.5V CC IOSD Driver Short-Circuit Output Current ±250 mA -7V  VOUT  +12V, Figure 5 DRIVER THERMAL CHARACTERISTICS TTS Thermal Shutdown Temperature 175 °C Junction temperature, Note 4 TTSH Thermal Shutdown Hysteresis 15 °C Note 4 3

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 Unless otherwise noted: V = +3.3V ±10%, T = T to T . Typical values are at V = 3.3V, T = +25°C. CC A MIN MAX CC A SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS RECEIVER DC CHARACTERISTICS Receiver Differential Threshold VTH Voltage (V - V ) -200 -125 -50 mV -7V  VCM  +12V A B VOH Receiver Input Hysteresis 25 mV VCM = 0V VOH Receiver Output High Voltage (RO) VCC-0.6 V IOUT = -1mA VOL Receiver Output Low Voltage (RO) 0.4 V IOUT = 1mA IOZR High-Z Receiver Output Current ±1 μA 0V  VOUT  VCC RIN Receiver Input Resistance 96 k -7V  VCM  +12V Receiver Output Short-Circuit IOSC ±80 mA 0V  VRO  VCC Current SUPPLY CURRENT No Load, RE = 0V, DE = V CC 425 600 μA DI = 0V No Load, RE = V , DE = V ICC Supply Current 330 600 μA CC CC DI = 0V No Load, RE = 0V, DE = 0V 300 500 μA Receiver A and B inputs open ISHDN Supply Current in Shutdown Mode 0.001 1 μA RE = VCC, DE = 0V ESD PROTECTION ±15 kV Human Body Model ESD Protection for A, B, Y, and Z ±15 kV IEC 61000-4-2 Airgap ±8 kV IEC 61000-4-2 Contact ESD Protection for all other pins ±4 kV Human Body Model 4

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS Unless otherwise noted: V = +3.3V ±10%, T = T to T . Typical values are at V = 3.3V, T = +25°C. CC A MIN MAX CC A SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER AC CHARACTERISTICS XR3070X, XR3071X and XR3072X (250kbps) tDPLH Driver Prop. Delay (Low to High) 250 1500 ns tDPHL Driver Prop. Delay (High to Low) 250 1500 ns C = 50pF, R = 54, L L |tDPLH-tDPHL| Differential Driver Output Skew 20 200 ns Figure 6 Driver Differential Output tDR, tDF Rise or Fall Time 350 1600 ns Maximum Data Rate 250 kbps 1/tUI, Duty Cycle 40 to 60% tDZH Driver Enable to Output High 200 2500 ns tDZL Driver Enable to Output Low 200 2500 ns C = 50pF, R = 500, L L tDHZ Driver Disable from Output High 6 100 ns Figure 7 tDLZ Driver Disable from Output Low 6 100 ns Driver Enable from Shutdown to tDZH(SHDN) Output High 5500 ns C = 50pF, R = 500, L L Driver Enable from Shutdown to Figure 7 tDZL(SHDN) Output Low 5500 ns tSHDN Time to Shutdown 50 200 600 ns Notes 3 and 4 RECEIVER AC CHARACTERISTICS XR3070X, XR3071X and XR3072X (250kbps) tRPLH Receiver Prop. Delay (Low to High) 200 ns C = 15pF, V = ±2V, L ID tRPHL Receiver Prop. Delay (High to Low) 200 ns VID Rise and Fall times < 15ns |t -t | Receiver Propagation Delay Skew 30 ns Figure 8 RPLH RPHL Maximum Data Rate 250 kbps 1/tUI, Duty Cycle 40 to 60% tRZH Receiver Enable to Output High 50 ns tRZL Receiver Enable to Output Low 50 ns C = 15pF, R = 1k, L L tRHZ Receiver Disable from Output High 50 ns Figure 9 tRLZ Receiver Disable from Output Low 50 ns Receiver Enable from Shutdown tRZH(SHDN) to Output High 3500 ns C = 15pF, R = 1k, L L Receiver Enable from Shutdown Figure 9 tRZL(SHDN) to Output Low 3500 ns tSHDN Time to Shutdown 50 200 600 ns Notes 3 and 4 5

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 Unless otherwise noted: V = +3.3V ±10%, T = T to T . Typical values are at V = 3.3V, T = +25°C. CC A MIN MAX CC A SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER AC CHARACTERISTICS XR3073X, XR3074X and XR3075X (1Mbps) tDPLH Driver Prop. Delay (Low to High) 150 300 ns tDPHL Driver Prop. Delay (High to Low) 150 300 ns C = 50pF, R = 54, L L |tDPLH-tDPHL| Differential Driver Output Skew 5 50 ns Figure 6 Driver Differential Output tDR, tDF Rise or Fall Time 100 200 300 ns Maximum Data Rate 1 Mbps 1/tUI, Duty Cycle 40 to 60% tDZH Driver Enable to Output High 1000 2500 ns tDZL Driver Enable to Output Low 1000 2500 ns C = 50pF, R = 500, L L tDHZ Driver Disable from Output High 60 100 ns Figure 7 tDLZ Driver Disable from Output Low 60 100 ns Driver Enable from Shutdown to tDZH(SHDN) Output High 3500 ns C = 50pF, R = 500, L L Driver Enable from Shutdown to Figure 7 tDZL(SHDN) Output Low 3500 ns tSHDN Time to Shutdown 50 200 600 ns Notes 3 and 4 RECEIVER AC CHARACTERISTICS XR3073X, XR3074X and XR3075X (1Mbps) tRPLH Receiver Prop. Delay (Low to High) 200 ns C = 15pF, V = ±2V, L ID tRPHL Receiver Prop. Delay (High to Low) 200 ns VID Rise and Fall times < 15ns |t -t | Receiver Propagation Delay Skew 30 ns Figure 8 RPLH RPHL Maximum Data Rate 1 Mbps 1/tUI, Duty Cycle 40 to 60% tRZH Receiver Enable to Output High 50 ns tRZL Receiver Enable to Output Low 50 ns C = 15pF, R = 1k, L L tRHZ Receiver Disable from Output High 50 ns Figure 9 tRLZ Receiver Disable from Output Low 50 ns Receiver Enable from Shutdown tRZH(SHDN) to Output High 3500 ns C = 15pF, R = 1k, L L Receiver Enable from Shutdown Figure 9 tRZL(SHDN) to Output Low 3500 ns tSHDN Time to Shutdown 50 200 600 ns Notes 3 and 4 6

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS Unless otherwise noted: V = +3.3V ±10%, T = T to T . Typical values are at V = 3.3V, T = +25°C. CC A MIN MAX CC A SYMBOL PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER AC CHARACTERISTICS XR3076X, XR3077X and XR3078X (20Mbps) tDPLH Driver Prop. Delay (Low to High) 25 ns tDPHL Driver Prop. Delay (High to Low) 25 ns C = 50pF, R = 54, L L |tDPLH-tDPHL| Differential Driver Output Skew 5 ns Figure 6 Driver Differential Output tDR, tDF Rise or Fall Time 15 ns Maximum Data Rate 20 Mbps 1/tUI, Duty Cycle 40 to 60% tDZH Driver Enable to Output High 45 ns tDZL Driver Enable to Output Low 45 ns C = 50pF, R = 500, L L tDHZ Driver Disable from Output High 40 ns Figure 7 tDLZ Driver Disable from Output Low 40 ns Driver Enable from Shutdown to tDZH(SHDN) Output High 250 ns C = 50pF, R = 500, L L Driver Enable from Shutdown to Figure 7 tDZL(SHDN) Output Low 250 ns tSHDN Time to Shutdown 50 200 600 ns Notes 3 and 4 RECEIVER AC CHARACTERISTICS XR3076X, XR3077X and XR3078X (20Mbps) tRPLH Receiver Prop. Delay (Low to High) 50 ns C = 15pF, V = ±2V, L ID tRPHL Receiver Prop. Delay (High to Low) 50 ns VID Rise and Fall times < 15ns |t -t | Receiver Propagation Delay Skew 5 ns Figure 8 RPLH RPHL Maximum Data Rate 20 Mbps 1/tUI, Duty Cycle 40 to 60% tRZH Receiver Enable to Output High 30 ns tRZL Receiver Enable to Output Low 30 ns C = 15pF, R = 1k, L L tRHZ Receiver Disable from Output High 30 ns Figure 9 tRLZ Receiver Disable from Output Low 30 ns Receiver Enable from Shutdown tRZH(SHDN) to Output High 1800 ns C = 15pF, R = 1k, L L Receiver Enable from Shutdown Figure 9 tRZL(SHDN) to Output Low 1800 ns tSHDN Time to Shutdown 50 200 600 ns Notes 3 and 4 7

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 NOTE: 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. 2. The hot swap feature disables the DE and RE inputs for the first 10μs after power is applied. Following this time period these inputs are weakly pulled to their disabled state (low for DE, high for RE) until the first transition, after which they become high impedance inputs. 3. The transceivers are put into shutdown by bringing RE High and DE Low simultaneously for at least 600ns. If the control inputs are in this state for less than 50ns, the device is guaranteed to not enter shutdown. If the enable inputs are held in this state for at least 600ns the device is assured to be in shutdown. Note that the receiver and driver enable times increase significantly when coming out of shutdown. 4. This spec is guaranteed by design and bench characterization. 8

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS BLOCK DIAGRAMS FIGURE 1. HALF DUPLEX (XR3072X, XR3075X, XR3078X) RO 1 R 8 V CC RE 2 7 B DE 3 6 A DI 4 D 5 GND FIGURE 2. FULL DUPLEX (XR3070X, XR3071X, XR3073X, XR3074X, XR3076X, XR3077X) N/C 1 14 V CC VCC 1 8 A RO 2 R 13 N/C R RO 2 7 B RE 3 12 A DI 3 6 Z DE 4 11 B D GND 4 5 Y DI 5 10 Z D GND 6 9 Y GND 7 8 N/C 9

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 TEST FIGURES FIGURE 3. DIFFERENTIAL DRIVER OUTPUT VOLTAGE Z R L 2 DI = 0V or V D V V CC OD CM R L 2 Y DE = V CC FIGURE 4. DIFFERENTIAL DRIVER OUTPUT VOLTAGE OVER COMMON MODE Z 375(cid:230) DI = 0V or V D V 60(cid:230) V CC OD CM 375(cid:230) Y DE = V CC FIGURE 5. DRIVER OUTPUT SHORT CIRCUIT CURRENT Z I OSD DI = 0V or V D CC -7Vto+12V V Y DE = 0V or V CC 10

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS FIGURE 6. DRIVER PROPAGATION DELAY TEST CIRCUIT & TIMING DIAGRAM Z DI D V R C OD L L Y DE = V CC 3V DI tSKEW=|tDPHL(cid:232)tDPLH| 1.5V 1.5V 0V t t DPLH DPHL Z V OD Y V OD+ 90% 90% V OD 0V (V -V ) Y Z V 10% 10% OD- t t DR DF 11

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 FIGURE 7. DRIVER ENABLE AND DISABLE TIMING TEST CIRCUITS & TIMING DIAGRAMS Z Testing Z: DI = 0V D V OUT Testing Y: DI = V CC R C DE L L Y 3V DE 1.5V 1.5V 0V t t DZH DHZ V OH V VOH+VOL VOH-0.25V OUT 2 V OL V CC Z R L Testing Z: DI = V CC D V OUT Testing Y: DI = 0V C DE L Y 3V DE 1.5V 1.5V 0V t t DZL DLZ V OH V +V V OH OL OUT 2 V +0.25V OL V OL 12

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS FIGURE 8. RECEIVER PROPAGATION DELAY TEST CIRCUIT & TIMING DIAGRAM B R RO C L A RE = 0V B +1V 0V A -1V t t RPLH RPHL V OH 1.5V 1.5V RO V OL 13

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 FIGURE 9. RECEIVER ENABLE AND DISABLE TEST CIRCUITS & TIMING DIAGRAMS B R RO R C RE L L A 3V RE 1.5V 1.5V 0V VA = VCC tRZH tRHZ V = 0V B V OH RO VOH VOH-0.25V 2 0V V CC B R L R RO C RE L A 3V RE 1.5V 1.5V 0V VA = 0V tRZL tRLZ V = V B CC V CC V +V RO CC OL 2 VOL+0.25V V OL 14

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS PIN DESCRIPTIONS PIN NUMBER HALF DUPLEX FULL DUPLEX PIN NAME TYPE DESCRIPTION XR3072X XR3071X XR3070X XR3075X XR3074X XR3073X XR3078X XR3077X XR3076X Receiver Output. When RE is low and 1 2 2 RO Out if (A-B)  -50mV, RO is high. If (A-B)  -200mV, RO is Low. Receiver Output Enable (Hot Swap). When RE is low, RO is enabled. When RE is High, 2 - 3 RE In RO is high impedance. RE should be high and DE should be low to enter shutdown mode. Driver Output Enable (Hot Swap). When DE is high, outputs are enabled. When DE is 3 - 4 DE In low, outputs are high impedance. DE should be low and RE should be high to enter shutdown mode. Driver Input. With DE high, a low level on DI forces non-Inverting 4 3 5 DI In output low and inverting output high. Similarly, a high level on DI forces non-Inverting output high and inverting output low. 5 4 6, 7 GND Pwr Ground. Non-Inverting Receiver Input and 6 - - A I/O Non-Inverting Driver Output. Inverting Receiver Input and 7 - - B I/O Inverting Driver Output. +3.3V Power Supply Input. 8 1 14 VCC Pwr Bypass to ground with 0.1 μF capacitor. - 8 12 A In Non-Inverting Receiver Input. - 7 11 B In Inverting Reciever Input. - 5 9 Y Out Non-Inverting Driver Output. - 6 10 Z Out Inverting Driver Output. - - 1, 8, 13 N/C - No Connect, not internally connected. 15

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 PRODUCT DESCRIPTION The XR3070-78X RS-485/422 devices are part of Exar’s X Series high performance serial interface product line. The analog bus pins can survive direct shorts up to ±18V, and are protected against ESD events up to ±15kV. The high output differential driver delivers 10% higher SNR than other RS-485/422 devices, affording additional noise margin or extended cable lengths. ENHANCED FAILSAFE Ordinary RS-485 differential receivers will be in an indeterminate state whenever the data bus is not being actively driven. The enhanced failsafe feature of the XR3070-78X family guarantees a logic-high receiver output when the receiver inputs are open, shorted, or when they are connected to a terminated transmission line with all drivers disabled. In a terminated bus with all transmitters disabled, the receivers’ differential input voltage is pulled to 0V by the termination. The XR3070-78X family interprets 0V differential as a logic high with a minimum 50mV noise margin while maintaining compliance with the EIA/TIA-485 standard of ±200mV. Although the XR3070-78X family does not need failsafe biasing resistors, it can operate without issue if biasing is used. RECEIVER INPUT FILTERING XR3070-75X receivers incorporate internal filtering in addition to input hysteresis. This filtering enhances noise immunity by ignoring signals that do not meet a minimum pulse width of 30ns. Receiver propagation delay increases slightly due to this filtering. The high speed XR3076X, XR3077X and XR3078X devices do not have this input filtering. HOT-SWAP CAPABILITY When V is first applied the XR3070-78X devices with DE and RE pins (70, 72, 73, 75, 76, & 78) hold the CC driver enable and receiver enable inactive for approximately 10 microseconds. During power ramp-up other system ICs may drive unpredictable values, or tristated lines may be influenced by stray capacitance. The hot- swap feature prevents these devices from driving any output signal until power has stabilized. After the initial 10μs, the driver and receiver enable pins are weakly pulled to their disabled states (low for DE, high for RE) until the first transition. After the first transition, the DE and RE pins operate as high impedance inputs. If circuit boards are inserted into an energized backplane (commonly called "live insertion" or "hot-swap") power may suddenly be 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. 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 thermal-shutdown circuit forces the driver outputs into a high-impedance state if junction temperature becomes excessive. LINE LENGTH The RS-485/RS-422 standard covers line lengths up to 4000ft. Maximum achievable line length is a function of signal attenuation and noise. Termination prevents signal reflections by eliminating the impedance mismatches on a transmission line. Line termination is generaly used if rise and fall times are shorter than the round-trip signal propagation time. Higher output drivers may allow longer cables to be used. 16

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS ±15kV ESD PROTECTION 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 XR3070-78X family have extra protection against static electricity. Exar 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 XR3070-78X keep operating without latch-up or damage. ESD protection can be tested in various ways. The transmitter outputs and receiver inputs of the XR3070-78X are characterized for protection to the following limits: ■ ±15kV using the Human Body Model ■ ± 8kV Contact Discharge Model ■ ±15kV Air-gap Discharge Model ESD TEST CONDITIONS ESD performance depends on a variety of conditions. Contact Exar for a reliability report that documents test setup, methodology and results. IEC 61000-4-2 The IEC 61000-4-2 standard covers ESD testing and performance of finished equipment. However, it does not specifically refer to integrated circuits. The XR3070-78X family helps you design equipment to meet IEC 61000-4-2, without sacrificing board-space and cost for external ESD-protection components. The major differences between tests done using the Human body model and IEC 61000-4-2 is a higher peak current in IEC 61000-4-2. Series resistance is lower in the IEC 61000-4-2 model. Hence, the ESD withstand voltage measured to IEC 61000-4-2 is generally lower than that of 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. 256 TRANSCEIVERS ON THE BUS The standard RS-485 receiver input impedance is 12k Ohms (1 unit load). A standard driver can drive up to 32 unit loads. The XR3070-78X family of transceivers have a 1/8th unit load receiver input impedance of 96k, allowing 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 draw less than 1μA 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 50ns. If the inputs are in this state for at least 600ns, the parts will enter shutdown. Enable times t and t apply when the part is not in low-power shutdown state. Enable times t and ZH ZL ZH(SHDN) t apply when the parts are shutdown. The drivers and receivers take longer to become enabled from ZL(SHDN) low-power shutdown t and t than from driver / receiver disable mode (t and t ). ZH(SHDN) ZL(SHDN) ZH ZL 17

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 FUNCTION TABLES TABLE 1: FULL DUPLEX 14 PIN - XR3070X, XR3073X AND XR3076X TRANSMITTING Inputs Outputs RE DE DI Y Z X 1 1 1 0 X 1 0 0 1 0 0 X High-Z 1 0 X Shutdown TABLE 2: FULL DUPLEX 8 PIN - XR3071X, XR3074X AND XR3077X TRANSMITTING Input Outputs DI Y Z 1 1 0 0 0 1 TABLE 3: HALF DUPLEX 8 PIN - XR3072X, XR3075X AND XR3078X TRANSMITTING Inputs Outputs RE DE DI A B X 1 1 1 0 X 1 0 0 1 0 0 X High-Z 1 0 X Shutdown 18

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS TABLE 4: FULL DUPLEX 14 PIN - XR3070X, XR3073X AND XR3076X RECEIVING Inputs Ouptut RE DE V - V RO A B 0 X  -50mV 1 0 X  -200mV 0 0 X Open/Shorted 1 1 1 X High-Z 1 0 X Shutdown TABLE 5: FULL DUPLEX 8 PIN - XR3071X, XR3074X AND XR3077X RECEIVING Inputs Output V - V RO A B  -50mV 1  -200mV 0 Open/Shorted 1 TABLE 6: HALF DUPLEX 8 PIN - XR3072X, XR3075X AND XR3078X RECEIVING Inputs Output RE DE V - V RO A B 0 X  -50mV 1 0 X  -200mV 0 0 X Open/Shorted 1 1 1 X High-Z 1 0 X Shutdown Note: Receiver inputs -200mV  V - V  -50mV are considered indeterminate. A B 19

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 PRODUCT SELECTOR GUIDE TABLE 7: SELECTION GUIDE RECEIVER PART TRANS ON DUPLEX DATA RATE SHUTDOWN AND DRIVER FOOTPRINT NUMBER BUS ENABLE XR3070XID-F Full Yes Yes 256 SN75180 XR3071XID-F Full 250kbps No No 256 SN75179 XR3072XID-F Half Yes Yes 256 SN75176 XR3073XID-F Full Yes Yes 256 SN75180 XR3074XID-F Full 1Mbps No No 256 SN75179 XR3075XID-F Half Yes Yes 256 SN75176 XR3076XID-F Full Yes Yes 256 SN75180 XR3077XID-F Full 20Mbps No No 256 SN75179 XR3078XID-F Half Yes Yes 256 SN75176 20

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS PACKAGE DRAWINGS FIGURE 10. 8 NSOIC 21

XR3070-78X LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REV. 1.0.0 FIGURE 11. 14 NSOIC 22

XR3070-78X REV. 1.0.0 LOW POWER 18V TOLERANT RS-485/RS-422 +3.3V TRANSCEIVERS REVISION HISTORY DATE REVISION DESCRIPTION Sept 2013 1.0.0 Production Release NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in 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 writing, 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 2013 EXAR Corporation Datasheet Sept 2013. 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. 23