MAX3480EA/MAX3480EB 19-1941 Rev 1 3/06 15kV ESD-Protected, Isolated, 3.3V RS-485/RS-422 Data Interfaces General Description Features The MAX3480EA/MAX3480EB are electrically isolated Isolated Data Interface Guaranteed to 1260V RMS RS-485/RS-422 data-communications interfaces. The (1min) RS-485/RS-422 I/O pins are protected against 15kV 15kV ESD Protection for I/O Pins electrostatic discharge (ESD) shocks, without latchup. Transceivers, optocouplers, and a transformer are all Slew-Rate-Limited Data Transmission (160kbps for included in one low-cost, 28-pin PDIP package. A sin- MAX3480EB) gle +3.3V supply on the logic side powers both sides High-Speed, Isolated, 2.5Mbps RS-485 Interface of the interface. (MAX3480EA) The MAX3480EB features reduced-slew-rate drivers that minimize EMI and reduce reflections caused by Single +3.3V Supply improperly terminated cables, allowing error-free data Current Limiting and Thermal Shutdown for transmission at data rates up to 160kbps. The Driver Overload Protection MAX3480EAs driver slew rate is not limited, allowing transmission rates up to 2.5Mbps. Standard 28-Pin PDIP Package Drivers are short-circuit current limited and are protect- Allows Up to 128 Transceivers on the Bus ed against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit. The MAX3480EA/MAX3480EB are guaranteed to with- stand 1260V (1min) or 1520V (1s). Their isolated RMS RMS Pin Configuration inputs and outputs meet RS-485/RS-422 specifications. TOP VIEW Applications MAX3480EA Isolated RS-485/RS-422 Data Interface MAX3480EB V AC1 CC1 1 28 Transceivers for EMI-Sensitive Applications V AC2 CC2 2 27 Industrial-Control Local Area Networks D1 ISO V Automatic Test Equipment 3 26 CC1 HVAC/Building Control Networks D2 4 25 B Telecom GND1 5 ISO RO DRV 24 MAX845 MAX1487E 6 23 FS A MAX487E Ordering Information SD 7 22 ISO DI IN 8 21 V ISO DE IN CC3 D A T A PI N - TEMP PKG DI ISO COM1 PART R A T E 9 20 RANGE PA C K A G E* CODE ( k b p s ) V 10 19 CC4 ISO DI DRV MAX3480EACPI 0C to +70 C 28 PDIP 2500 P28M-1 ISO V DE 11 18 CC2 MAX3480EAEPI - 40C to +85 C 28 PDIP 2500 P28M-1 GND2 12 17 ISO DE DRV MAX3480EBCPI 0C to +70 C 28 PDIP 250 P28M-1 RO 16 ISO COM2 13 MAX3480EBEPI - 40C to +85 C 28 PDIP 250 P28M-1 V 15 ISO RO LED CC5 14 *See the Reliability section at end of data sheet. ISOLATION BARRIER PDIP Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.15kV ESD-Protected, Isolated, 3.3V RS-485/RS-422 Data Interfaces ABSOLUTE MAXIMUM RATINGS With Respect to GND LED Forward Current (DI, DE, ISO RO LED) ......................50mA Supply Voltage (V V V V ) .......-0.3V to +3.8V Continuous Power Dissipation (T = +70C) CC1, CC2, CC4, CC5 A Supply Voltage (V ) ........................................-0.3V to +7V 28-Pin PDIP (derate 9.09mW/C above +70C)............727mW CC3 Control Input Voltage (SD, FS) ............-0.3V to (V + 0.3V) Operating Temperature Ranges CC3 Receiver Output Voltage (RO).............-0.3V to (V + 0.3V) MAX3480E CPI..................................................0C to +70C CC5 With Respect to ISO COM MAX3480E EPI...............................................-40C to +85C Control Input Voltage (ISO DE )......-0.3V to (ISO V + 0.3V) Storage Temperature Range .............................-65C to +150C CC Driver Input Voltage (ISO DI ) .....-0.3V to (ISO V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC Receiver Output Voltage (ISO RO ) ..-0.3V to (ISO V + 0.3V) CC Driver Output Voltage (A, B)..............................-8V to +12.5V Receiver Input Voltage (A, B)............................-8V to +12.5V 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. ELECTRICAL CHARACTERISTICS (V = V = V = V = V = +3.0V to +3.6V, FS = 0, T = T to T , unless otherwise noted. Typical values are at V = CC CC1 CC2 CC4 CC5 A MIN MAX CC +3.3V and T = +25C.) (Notes 1, 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS f FS = 0 60 SWL Switch Frequency kHz f FS = V or open 900 SWH CC R = 130 250 MAX3480EA, L DE = V or open CC R = 54 220 L Operating Supply Current I mA CC R = 80 200 MAX3480EB, L DE = V or open CC R = 54 180 L Shutdown Supply Current (Note 3) I SD = V 0.2 A SHDN CC3 V High 2.4 FSH FS Input Threshold V V Low 0.8 FSL FS Input Pullup Current I FS low 50 A FSL FS Input Leakage Current I FS high 10 pA FSM Input High Voltage V DE, DI, Figure 1 V - 0.4 V IH CC Input Low Voltage V DE, DI, Figure 1 0.4 V IL Isolation Voltage V T = +25C, 1min (Note 4) 1260 V ISO A RMS V High 2.4 1 SDH Shutdown Input Threshold V V Low 1 0.8 SDL Isolation Resistance R T = +25C, V = 50VDC 100 10,000 M ISO A ISO Isolation Capacitance C f = 1MHz 10 pF ISO A, B, Y, and Z pins, tested at Human Body ESD Protection ESD 15 kV Model Differential Driver Output V 8V OD1 (No Load) R = 50 (RS-422) 2 Differential Driver Output V V OD2 R = 27 (RS-485), Figure 3 1.5 5.0 Change in Magnitude of Driver Differential 0.3 R = 27 or 50 , Output Voltage for Complementary V V OD Figure 3 Common mode 0.3 Output States 2 MAX3480EA/MAX3480EB