EVALUATION KIT AVAILABLE MAX14940 2.75kV Isolated 20Mbps Half-Duplex RMS PROFIBUS/RS-485 Transceiver with 35kV ESD Protection and Integrated Transformer Driver General Description Benefits and Features The MAX14940 isolated RS-485/PROFIBUS-DP High Integration Simplifies Designs transceiver provides 2750V (60s) of galvanic isolation Integrated LDO for Cable-Side Power Can Also RMS between the cable-side (RS-485 driver/receiver-side) and Power External Loads Up to 10mA the UART-side of the device. Isolation improves communication Integrated Transformer Driver for Power Transfer to Cable-Side Has Up to 80% Efficiency at 150mA Load by breaking ground loops and reduced noise when there are large differences in ground potential between ports. High-Performance Transceiver Enables Flexible This device allows for robust communication up to 20Mbps. Designs The MAX14940 includes an integrated 450kHz transformer Compliant with RS-485 EIA/TIA-485 and EIA driver for power transfer to the cable-side of the transceiver 61158-2 Type 3 PROFIBUS-DP Standards using an external transformer. An integrated LDO provides 20Mbps (max) Data Rate a simple and space-efficient way of designing an isolated Up to 128 Devices on the Bus DC/DC supply. Integrated Protection for Robust Communication The MAX14940 includes one half-duplex driver/receiver 35kV ESD (HBM) on Driver Outputs/Receiver channel that is fully compliant with both RS-485 and Inputs PROFIBUS-DP standards. The receiver is 1/4-unit load, 2.75kV Withstand Isolation Voltage for 60 RMS allowing up to 128 transceivers on a common bus. Seconds (V ) ISO 630V Maximum Repetitive Peak Isolation PEAK Integrated true fail-safe circuitry ensures a logic-high on Voltage (V ) IORM the receiver output when inputs are shorted or open. 445V Maximum Working Isolation Voltage (V ) RMS IOWM Undervoltage lockout disables the driver when cable-side > 30 Years Lifetime at Rated Working Voltage or UART-side power supplies are below functional levels. Withstands 10kV Surge per IEC 61000-4-5 The driver outputs/receiver inputs are protected from Thermal Shutdown 35kV electrostatic discharge (ESD) to GNDB on the cable-side, as specified by the Human Body Model Ordering Information appears at end of data sheet. (HBM). The MAX14940 is available in a wide body 16-pin SOIC package and operates over the -40C to +105C Functional Diagram temperature range. Applications VDDA TD1 TD2 VLDO Industrial Automation Equipment Programmable Logic Controllers MAX14940 HVAC LDO XFMR Power Meters DRIVER VDDB RE Safety Regulatory Approvals Pending UL According to UL1577 RXD A cUL According to CSA Bulletin 5A TXD B DE DEM The PROFIBUS PROCESS FIELD BUS logo is a registered GNDA GNDB trademark of PROFIBUS and PROFINET International (PI). 19-7760 Rev 2 10/17 RS-485 TRANSCEIVERMAX14940 2.75kV Isolated 20Mbps Half-Duplex RMS PROFIBUS/RS-485 Transceiver with 35kV ESD Protection and Integrated Transformer Driver Absolute Maximum Ratings V to GNDA .......................................................-0.3V to +6V V to GNDB) ...................................................Continuous DDA DDB 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 DEM to GNDB ........................................................-0.3V to +6V Storage Temperature Range ............................ -65C to +150C A, B to GNDB ...........................................................-8V to +13V Lead Temperature (soldering, 10s) .................................+300C TD1, TD2 Continuous Current ...........................................1.4A Soldering Temperature (reflow) .......................................+260C Short-Circuit Duration (RXD to GNDA, A, B, DEM, 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-Case Thermal Resistance ( ) ...................71C/W Junction-to-Ambient Thermal Resistance ( ) ..............23C/W JC JA 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 load, 4.7 7.7 DDA TD1/TD2 unconnected Supply Current mA DE = high, RE = TXD = low, RXD I 7.7 12.5 DDB unconnected, no 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