SP1486E +5V, 20Mbps PROFIBUS RS485/RS422 Transceivers Advanced Failsafe, 1/8th Unit Load, 15kV ESD-Protected FEATURES +5V Recommended for PROFIBUS applications 100nF High differential output drive, minimum 2.1V into 54 load RO V 1 CC 8 5.0V Single Supply Operation B R ns driver and receiver skew RE B 2 7 20 Mbps data rate RT /8th Unit Load, 256 transceivers on bus DE A Robust ESD Protection for RS485 pins 3 6 15kV Air-Gap Discharge D 15kV Human Body Model 4 5 GND DI 8kV Contact Discharge Hot Swap glitch protection on control inputs SP1486E Receiver failsafe on open, short or terminated lines APPLICATIONS Driver short circuit current limit and High Speed RS485 Communications thermal shutdown for overload protection Industrial Process Control Very low 300A static power consumption PROFIBUS applications 1A shutdown mode DESCRIPTION SP 486E is a half duplex differential line transceiver suitable for high speed bidirectional commu - nication on multipoint bus transmission lines. Each device contains one differential driver and one differential receiver. Devices comply with TIA/EIA-485 and TIA/EIA-422 standards and also meet the higher drive and tighter skew requirements of PROFIBUS applications. Lead-free and RoHS compli- ant packages are available for all models. PROFIBUS is in wide use in industrial control and automation applications and the SP 486E is rug - gedized for use in harsh operating conditions. Receivers are specially designed to fail-safe to a logic high output state if the inputs are left un-driven or shorted. All RS485 bus-pins are protected against severe ESD events up to 5kV (Air-Gap and Human Body Model) and up to 8kV Contact Discharge (IEC 1000-4-2). Drivers are protected from excess current flow caused by bus contention or output short-circuits by both an internal current limit and a thermal-overload shutdown. Devices are rated for Industrial (-40 to +85C) operating temperature. Receivers have exceptionally high input impedance, which places only /8th the standard load on a shared bus. Up to 256 transceivers may coexist while preserving full signal margin. All devices operate from a single 5.0 V power supply and draw negligible quiescent power. Both driver and receiver can be enabled and disabled independently and the device enters a low power shutdown mode if both driver and receiver are disabled. The bus-pin outputs of disabled modules are in high impedance state. The high impedance driver output is maintained over the entire common-mode volt- age range from -7 to +2V . Exar Corporation 48720 Kato Road, Fremont CA, 94538 5 0-668-70 7 www.exar.com SP 486E 0 007 0 PIN ASSIGNMENTS Pin Name Pin Function Pin Function RO Receiver Output. When RE is low and if (A B) -40mV, RO is High. If (A B) - 200mV, RO is low. 2 RE Receiver Output Enable. RO is enabled when RE is low. When RE is high, RO is high imped- ance. Drive RE high and DE low to enter shutdown mode. RE is a hot-swap input. 3 DE Driver Output Enable. When DE is high, outputs are enabled. When DE is low, outputs are high impedance. Drive DE low and RE high to enter shutdown mode. DE is a hot-swap input. 4 DI Driver Input. With DE high, a low level on DI forces non-inverting output low and inverting out- put high. Similarly, a high level on DI forces non-inverting output high and inverting output low. 5 GND Ground 6 A Non-inverting Receiver Input and Non-inverting Driver Output 7 B Inverting Receiver Input and Inverting Driver Output 8 Vcc Positive Supply Vcc. Bypass Vcc to GND with a 0. uF capacitor. Exar Corporation 48720 Kato Road, Fremont CA, 94538 5 0-668-70 7 www.exar.com SP 486E 0 007 0 2