EVALUATION KIT AVAILABLE MAX14949 5kV Isolated 500kbps Half-Duplex RMS RS-485/RS-422 Transceiver with 30kV ESD Protection and Integrated Transformer Driver General Description Benefits and Features The MAX14949 isolated RS-485/RS-422 transceiver provides High Integration Simplifies Designs 5000V (60s) of galvanic isolation between the cable- Integrated LDO for Cable-Side Power RMS side (RS-485/RS-422 driver/receiver-side) and the UART- Integrated Transformer Driver for Power Transfer to Cable-Side Has Up to 80% Efficiency at 150mA Load side of the device. Isolation improves communication by breaking ground loops and reduces noise when there are High-Performance Transceiver Enables Flexible Designs large differences in ground potential between ports. This Compliant with RS-485 EIA/TIA-485 Standard device allows for robust communication up to 500kbps. 500kbps (max) Data Rate The device includes an integrated 450kHz transformer Up to 256 Devices on the Bus driver for power transfer to the cable-side of the transceiver Integrated Protection for Robust Communication using an external transformer. An integrated LDO provides 30kV ESD (HBM) on Driver Outputs/Receiver Inputs a simple and space-efficient architecture for providing 5kV Withstand-Isolation Voltage for 60 RMS power to the cable-side of the IC. Seconds (V ) ISO 1200V Maximum Repetitive Peak-Isolation The device includes one half-duplex driver/receiver PEAK Voltage (V ) channel. The receiver is 1/8-unit load, allowing up to 256 IORM 848V Maximum Working-Isolation Voltage (V ) transceivers on a common bus. RMS IOWM >30 Years Lifetime at Rated Working Voltage Integrated true fail-safe circuitry ensures a logic-high on Withstands 10kV Surge per IEC 61000-4-5 the receiver output when inputs are shorted or open. Thermal Shutdown Undervoltage lockout disables the driver when cable-side or UART-side power supplies are below functional levels. The driver outputs/receiver inputs are protected from Functional Diagram 30kV electrostatic discharge (ESD) to GNDB on the cable-side, as specified by the Human Body Model (HBM). The MAX14949 is available in a wide body 16-pin VDDA TD1 TD2 VLDO SOIC package and operates over the -40C to +85C temperature range. MAX14949 LDO XFMR Applications DRIVER VDDB Industrial Automation Equipment RE Programmable Logic Controllers HVAC RXD A Power Meters TXD B Safety Regulatory Approvals Pending DE UL According to UL1577 DEM GNDA GNDB Ordering Information appears at end of data sheet . 19-7663 Rev 2 10/17 RS-485 TRANSCEIVERMAX14949 5kV Isolated 500kbps Half-Duplex RMS RS-485/RS-422 Transceiver with 30kV ESD Protection and Integrated Transformer Driver Absolute Maximum Ratings V to GNDA .......................................................-0.3V to +6V Short-Circuit Duration (RXD to GNDA, A, B, DEM, DDA V to GNDB ........................................................-0.3V to +6V V to GNDB) ....................................................Continuous DDB DDB V to GNDB ......................................................-0.3V to +16V Continuous Power Dissipation (T = +70C) LDO A TD1, TD2 to GNDA ..............................................-0.3V to +12V 16-pin Wide SOIC TXD, DE, RE to GNDA ...........................................-0.3V to +6V (derate 14.1mW/C above +70C) .........................1126.8mW RXD to GNDA.........................................-0.3V to (V + 0.3V) Operating Temperature Range ........................... -40C to +85C DDA DEM to GNDB ........................................................-0.3V to +6V Junction Temperature ......................................................+150C A, B to GNDB ...........................................................-8V to +13V Storage Temperature Range ............................ -65C to +150C TD1, TD2 Continuous Current ...........................................1.4A Lead Temperature (soldering, 10s) .................................+300C Soldering Temperature (reflow) .......................................+260C 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 = 4.5V 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 = 5V, V = V , and T = +25C.) (Notes 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 4.5 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 I 6.3 12.5 DDB unconnected, no bus load, V = 5V 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