EVALUATION KIT AVAILABLE MAX14945 2.75kV Isolated 500kbps Half-Duplex RS-485/ RMS RS-422 Transceiver with 30kV ESD Protection General Description Benefits and Features The MAX14945 isolated RS-485/RS-422 transceiver provides High-Performance Transceiver Enables Flexible Designs 2750V (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 Compliant with RS-485 EIA/TIA-485 Standard 500kbps Maximum Data Rate side of the device. Isolation improves communication by breaking ground loops and reduces noise when there Allows Up to 256 Devices on the Bus are large differences in ground potential between ports. Integrated Protection Ensures Robust Communication Signals are passed across the isolation barrier through 30kV ESD (HBM) on Driver Outputs/Receiver Inputs integrated high-voltage capacitors. This device allows for 2.75kV Withstand-Isolation Voltage for 60s (V ) RMS ISO robust communication at any speed up to 500kbps. 630V Maximum Repetitive Peak-Isolation PEAK The device includes one half-duplex drive/receive channel. Voltage (V ) IORM The receiver is 1/8-unit load, allowing up to 256 transceivers 445V Maximum Working-Isolation Voltage (V ) RMS IOWM 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 the Thermal Shutdown receiver output when inputs are shorted or open. Undervoltage lockout disables the driver when the cable side or UART side Safety Regulatory Approvals power supplies are below functional levels. UL According to UL1577 The driver outputs/receiver inputs are protected from cUL According to CSA Bulletin 5A 30kV electrostatic discharge (ESD) to GNDB on the Applications cable side, as specified by the Human Body Model (HBM). Industrial Automation Equipment The MAX14945 is available in a wide body 16-pin Programmable Logic Controllers SO package and operates over the -40C to +85C HVAC temperature range. Power Meters Functional Diagram Ordering Information/Selector Guide appears at end of data sheet. VDDA VLDO MAX14945 LDO VDDB SBA RE RXD A TXD B DE GNDA GNDB 19-7967 Rev 1 1/17 RS-485 TRANSCEIVERMAX14945 2.75kV Isolated 500kbps Half-Duplex RS-485/ RMS RS-422 Transceiver with 30kV ESD Protection Absolute Maximum Ratings V to GNDA .......................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) DDA A V to GNDB ........................................................-0.3V to +6V 16-pin Wide SOIC DDB V to GNDB ......................................................-0.3V to +16V (derate 14.1mW/C above +70C) .........................1126.8mW LDO TXD, DE, RE to GNDA ...........................................-0.3V to +6V Operating Temperature Range ........................... -40C to +85C SBA, RXD to GNDA ............................... -0.3V to (V + 0.3V) Junction Temperature ......................................................+150C DDA A, B to GNDB ...........................................................-8V to +13V Storage Temperature Range ............................ -65C to +150C Short Circuit Duration (RXD, SBA to GNDA, Lead Temperature (soldering, 10s) .................................+300C A, B, V to GNDB).............................................Continuous Soldering Temperature (reflow) .......................................+260C 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 = 1.71V 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 1.71 5.5 DDA Supply Voltage V V 4.5 5.5 DDB V = 5V, DE = high, RE = TXD = DDA I 4 6.6 DDA low, RXD unconnected, no load Supply Current mA DE = high, RE = TXD = low, RXD I 6.3 12.5 DDB unconnected, no load, V = 5V DDB V V rising 1.50 1.58 1.65 UVLOA DDA Undervoltage-Lockout Threshold V V V rising 2.55 2.7 2.85 UVLOB DDB V 50 Undervoltage-Lockout UVHYSTA mV Threshold Hysteresis V 200 UVHYSTB LDO LDO Supply Voltage V Relative to GNDB, LDO is on (Note 4) 4.68 14 V LDO DE = high, RE = TXD = low, no load, LDO Supply Current I 6.5 12.9 mA LDO V = 5.5V LDO LDO Output Voltage V 4.5 5 5.5 V DDB LDO Current Limit 300 mA V = 5.68V, I = 20mA to LDO LOAD Load Regulation 0.19 1.7 mV/mA 40mA Line Regulation V = 5.68V to 14V, I = 20mA 0.12 1.8 mV/V LDO LOAD Maxim Integrated 2 www.maximintegrated.com