SP3494 +3.3V Low Power RS-485/RS-422 Transceiver Operates From A Single +3.3V Supply Interoperable With +5.0V Logic +/-200mV Receiver Input Sensitivity -7V to +2V Common-Mode Input V oltage Range Allows Up To 32 transceivers On The Serial Bus Driver/Receiver Enable Lines 0A Low-Power Shutdown Mode Compatibility with the MAX3486 and 75 76 Industry Standard Pinout DESCRIPTION The SP3494 device is a +3.3V low power half-duplex transceiver that meets the specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compatible with the Exar SP348 device as well as other popular industry standards. The SP3494 features the Exar BiCMOS process, allowing low power operation without sacrificing performance. The partially slew-rate limited drivers minimize EMI and reduce reefl ctions caused by improperly terminated cables allowing error-free data transmission.The SP3494 is a half-duplex partially slew-rate limited transceiver that will deliver a data transmission rate up to 2.5Mbps. The SP3494 is equipped with a low-power shutdown mode and driver/receiver high-Z enable lines. Exar Corporation 48720 Kato Road, Fremont CA, 94538 50-668-70 7 www .exar.com SP3494 00 07 0 2 ABSOLUTE MAXIMUM RATINGS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. V .....................................................................+6.0V CC Input Voltages Drivers.................................-0.3V to +6.0V Receivers.........................................+/-4V Output Voltages Drivers.............................................+/-4V Receivers............................-0.3V to +6.0V Storage Temperature.......................-65C to +150C Power Dissipation 8-pin NSOIC...................................................600mW (derate 6.90mW/C above +70C) ELECTRICAL CHARACTERISTICS T = T to T and V = +3.3V +/-5% unless otherwise noted. AMB MIN MAX CC PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP3494 DRIVER DC Characteristics Differential Output Voltage GND Vcc Volts Unloaded R = Figure 1 Differential Output Voltage 2 Vcc Volts With Load R = 50 (RS-422) Figure Differential Output Voltage .5 Vcc Volts With Load R = 27 (RS-485) Figure Change in Magnitude of Driver 0.2 Volts R = 27 or R = 50 Figure 1 Differential Output Voltage for Complimentary states Driver Common-Mode Output 3 Volts R = 27 or R = 50 Figure 1 Voltage Input High Voltage 2.0 Volts Applies to DE, DI, RE Input Low Voltage 0.8 Volts Applies to DE, DI, RE Input Current +/-0 A Applies to DE, DI, RE Driver Short Circuit Current +/-250 mA -7V V +12V Figure 8 O V = HIGH OUT Driver Short Circuit Current +/-250 mA -7V V +12V Figure 8 O V = LOW OUT SP3494 DRIVER AC Characteristics Maximum Data Rate 2.5 Mbps RE = V , DE = V CC CC Driver Input to Output, t 20 45 75 ns Figures 2 & 9 PLH Driver Input to Output, t 20 45 75 ns Figures 2 & 9 PHL Differential Driver Skew 0 ns t - t , Figures 2 and 0 DO DO2 Driver Rise or Fall Time 30 70 ns From 0%-90% Figures 3 and 0 Exar Corporation 48720 Kato Road, Fremont CA, 94538 50-668-70 7 www .exar.com SP3494 00 07 0 2 2