EVALUATION KIT AVAILABLE MAX14857/MAX14859 5kV Isolated 500kbps/25Mbps Full-Duplex RMS RS-485/RS-422 Transceivers with 35kV ESD Protection and Integrated Transformer Driver General Description Benefits and Features The MAX14857/MAX14859 isolated RS-485/RS-422 High Integration Simplifies Designs transceivers provide 5000V (60s) of galvanic isola- Integrated LDO for Cable-Side Power RMS tion between the cable-side (RS-485/RS-422 driver/ Integrated Transformer Driver for Power Transfer to receiver-side) and the UART-side of the device. Isolation Cable-Side Has Up to 80% Efficiency at 150mA Load improves communication by breaking ground loops and High-Performance Transceiver Enables Flexible Designs reduces noise when there are large differences in ground Compliant with RS-485 EIA/TIA-485 Standard potential between ports. These devices allow for robust 500kbps (MAX14857)/25Mbps (MAX14859) communication up to 500kbps (MAX14857) or 25Mbps Maximum Data Rate (MAX14859). Up to 128 Devices on the Bus The devices include an integrated 450kHz transformer Integrated Protection for Robust Communication driver for power transfer to the cable-side of the transceiver 35kV ESD (HBM) on Driver Outputs/Receiver Inputs using an external transformer. An integrated LDO provides 5kV Withstand Isolation Voltage for 60 RMS a simple and space-efficient architecture for providing Seconds (V ) ISO power to the cable-side of the IC. 1200V Maximum Repetitive Peak Isolation PEAK The devices include one drive channel and one receive Voltage (V ) IORM channel. The receiver is -unit load, allowing up to 128 848V Maximum Working Isolation Voltage (V ) RMS IOWM transceivers on a common bus. >30 Years Lifetime at Rated Working Voltage Withstands 10kV Surge per IEC 61000-4-5 Integrated true fail-safe circuitry ensures a logic-high on Thermal Shutdown the receiver output when inputs are shorted or open. Undervoltage lockout disables the driver when cable-side or UART-side power supplies are below functional levels. The driver outputs and receiver inputs are protected from 35kV electrostatic discharge (ESD) to GNDB on the cable-side, as specified by the Human Body Model Functional Diagram (HBM). The MAX14857/MAX14859 are available in a wide body 16-pin SOIC package and operate over the -40C to +105C V TD1 TD2 V DDA LDO temperature range. MAX14857 Applications MAX14859 LDO Industrial Automation Equipment XFMR DRIVER V DDB Programmable Logic Controllers RE A HVAC RXD B Power Meters TXD Z Safety Regulatory Approvals DE Y UL According to UL1577 cUL According to CSA Bulletin 5A GNDA GNDB Ordering Information appears at end of data sheet. 19-7689 Rev 3 10/17 RS-485 TRANSCEIVERMAX14857/MAX14859 5kV Isolated 500kbps/25Mbps Full-Duplex RMS RS-485/RS-422 Transceivers with 35kV ESD Protection and Integrated Transformer Driver Absolute Maximum Ratings V to GNDA .......................................................-0.3V to +6V DDA V to GNDB .......................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) DDB A V to GNDB .....................................................-0.3V to +16V 16-pin Wide SOIC LDO TD1, TD2 to GNDA ..............................................-0.3V to +12V (derate 14.1mW/C above +70C) .........................1126.8mW TXD, DE, RE to GNDA ...........................................-0.3V to +6V Operating Temperature Range ......................... -40C to +105C RXD to GNDA .......................................-0.3V to (V + 0.3V) Junction Temperature ......................................................+150C DDA A, B, Y, Z to GNDB ...................................................-8V to +13V Storage Temperature Range ............................ -65C to +150C TD1, TD2 Continuous Current .............................................1.4A Lead Temperature (soldering, 10s) .................................+300C Short-Circuit Duration (RXD to GNDA, A, B, Y, Z, Soldering Temperature (reflow) .......................................+260C V to GNDB) ...................................................Continuous DDB 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. Package Thermal Characteristics (Note 1) Junction-to-Ambient Thermal Resistance ( ) ..............71C/W Junction-to-Case Thermal Resistance ( ) ...................23C/W JA JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. DC Electrical Characteristics (V - V = 3.0V to 5.5V, V - V = 3.0V to 5.5V, T = T to T , unless otherwise noted. Typical values are at DDA GNDA DDB GNDB A MIN MAX V - V = 3.3V, V - V = 3.3V, V = V , and T = +25C.) (Note 2, 3) DDA GNDA DDB GNDB GNDA GNDB A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER V 3.0 5.5 DDA Supply Voltage V V 3.0 5.5 DDB V = 5V, DE = high, RE = TXD = DDA I low, RXD unconnected, no bus load, 4.7 7.7 DDA TD1/TD2 unconnected Supply Current mA DE = high, RE = TXD = low, RXD un- I 7.4 12.5 DDB connected, no bus load, V = 3.3V DDB RE, RXD, DE, TXD, V rising 1.50 1.58 1.65 DDA V Undervoltage Lockout UVLOA TD1/TD2 driver, V rising 2.55 2.7 2.85 V DDA Threshold V V rising 2.55 2.7 2.85 UVLOB DDB RE, RXD, DE, TXD 50 V Undervoltage Lockout UVHYSTA TD1/TD2 driver 200 mV Threshold Hysteresis V 200 UVHYSTB TRANSFORMER DRIVER Output Resistance R TD1/TD2 = low, I = 300mA 0.6 1.5 O OUT 4.5V V 5.5V 540 785 1300 DDA TD1, TD2 Current Limit I mA LIM 3.0V V 3.6V 485 730 1170 DDA Switching Frequency f 350 450 550 kHz SW Duty Cycle D 50 % Crossover Dead Time t 50 ns DEAD Maxim Integrated 2 www.maximintegrated.com