SP495 SIPEX | Alldatasheet

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SP495 Quad Differential RS-485 Transceiver © Copyright 2000 Sipex Corporation OA1 OB1 OA2 OB2 V DESCRIPTION… The SP495 is a quad differential line driver/receiver meeting both RS-485 and RS-422 standards at data rates beyond 10Mbps. The SP495 features three half-duplex transceivers suitable for data bus connections and a fourth full-duplex transceiver with independent driver, receiver enables. Ideal for use as a control bus transceiver. A complete SCSI initiator or target interface can be implemented using five SP495 s. Propagation Delay Skew is tightly specified to aid in parallel interface designs. The SP495 is available in a 20-pin plastic SOIC package for operation over the commercial and industrial temperature ranges. For PLCC availability, please consult factory. n Pinout for SCSI Interface n Meets EIA-485 Standard for Multipoint Bus Transmission n +5V-Only Power Supply Required n Receiver Fail-Safe Mode n Low Power BiCMOS Technology n Glitch-Free Power-Up/Down n Available in 20-Pin Plastic SOIC n Pin Compatible with DS36954 SP495 R 4 D 4 R 3 D 3 R 2 D 2 R 1 D 1 20 19 18 17 16 2 1 3 4 11 15 14 13 12 6 5 8 9 7 10 DR1 DE1/RE1 DR2 DE2/ RE2GND DR3 DE3/ RE3 DI4 DE4 RO4 RE4 cc OA3 OB3 OA4 OB4 SP495 Quad Differential RS-485 Transceiver

SP495 Quad Differential RS-485 Transceiver © Copyright 2000 Sipex Corporation SPECIFICATIONS TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER DC Characteristics Differential Output Voltage GND V CC Volts Unloaded; R = ∞ ; see Figure 1 Differential Output Voltage 2 V CC Volts With Load; R = 50Ω ; (RS-422); see Figure 1 Differential Output Voltage 1.5 V CC Volts With Load; R = 27Ω ; (RS-485); see Figure 1 Change in Magnitude of Driver Differential Output Voltage for Complimentary States 0.2 Volts R = 27 Ω or R = 50Ω ; see Figure 1 Driver Common-Mode Output Voltage 3 Volts R = 27 Ω or R = 50Ω ; see Figure 1 Input High Voltage 2.0 Volts Applies to DRx, DEx/ REx Input Low Voltage 0.8 Volts Applies to DRx, DEx/ REx Input Current ±10 µA Applies to DRx, DEx/ REx Driver Short-Circuit Current V OUT = HIGH ±250 mA -7V ≤ VO ≤ 10V VOUT = LOW ±250 mA -7V ≤ VO ≤ 10V DRIVER AC Characteristics Maximum Driver Data Rate 10 Mbps R DIFF = 54Ω , CL1 = CL2 = 100pF Driver Input to Output 20 30 60 ns t PLH ; RDIFF = 54Ω , CL1 = CL2 = 100pF; see Figures 3 and 6 Driver Input to Output 20 30 60 ns t PHL ; RDIFF = 54Ω , CL1 = CL2 = 100pF; see Figures 3 and 6 Driver Skew 10 ns see Figures 3 and 6 Driver Rise or Fall Time 3 15 40 ns From 10% to 90%; R DIFF = 54Ω , C L1 = CL2 = 100pF; see Figures 3 and 6 Driver Enable to Output HIGH 40 70 ns C L1 = CL2 = 100pF; see Figures 4 and 7; S2 closed Driver Enable to Output LOW 40 70 ns C L1 = CL2 = 100pF; see Figures 4 and 7; S1 closed Driver Disable Time from LOW 40 70 ns C L1 = CL2 = 15pF; see Figures 4 and 7; S1 closed Driver Disable Time from HIGH 40 70 ns C L1 = CL2 = 15pF; see Figures 4 and 7; S2 closed RECEIVER DC Characteristics Differential Input Threshold -0.2 +0.2 Volts -7V ≤ VCM ≤ 12V Input Hysteresis 70 mV V CM = 0V Output Voltage HIGH 3.5 Volts I O = -4mA, VID = +200mV 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 Input Voltages Output Voltages CC +0.5V)

SP495 Quad Differential RS-485 Transceiver © Copyright 2000 Sipex Corporation +3V RE R 1.5V 1.5V tZL tZH f = 1MHz; tR < 10ns; tF < 10ns R 1.5V 1.5V tLZ tHZ 0.5V 0.5V Output normally LOW Output normally HIGH VIL VIH Figure 9. Receiver Enable and Disable Times

DESCRIPTION

General Description... The SP495 is a quad differential transceiver that meets the requirements of RS-485, RS-422, and differential SCSI at data rates to beyond 10Mbps. Fabricated with a proprietary Sipex BiCMOS process, the SP495 requires only a fraction of the power of older bipolar designs. The SP495 features three half-duplex transceivers suitable for data bus connections and a fourth full-duplex transceiver with independent enables ideal for use as a control bus transceiver. A complete SCSI initiator or target interface can be implemented using five SP495 s. The RS-485 standard is ideal for multi-drop applications and for long-distance interfaces. RS-485 allows up to 32 drivers and 32 receivers to be connected to a single data bus, making it an ideal choice for multi-drop applications. Since the cabling can be as long as 4,000 feet, RS-485 transceivers are specified for operation with a wide (-7V to +12V) common mode range to accommodate ground potential differences. Because RS-485 is a low impedance differential interface, data is virtually immune to noise in the transmission line. Drivers... The differential drivers for the SP495 have typical output voltage swings (no load) of 0 to +5Volts. With loading to the RS-485 specification (54Ω ), drivers must maintain outputs greater than 1.5V. The three half-duplex drivers of the SP495 have independent Driver Enable control lines which are active HIGH. A logic HIGH on DEx (pins 1, 4, or 5 of the SP495 ) will enable the addressed differential driver output. A logic LOW on DEx will tri-state the driver output and enable the receiver. The fourth driver is controlled by its own DE4 Enable line and can be used in half - duplex or full-duplex modes. Receivers... The differential receivers for the SP495 have an input sensitivity of ±200mV. Input impedance is typically 15kΩ (12kΩ minimum). A wide common mode range of -7V to +12V allows for large ground potential differences between widely separated systems. These receivers are equipped with a fail-safe feature which guarantees that the receiver output will be in a HIGH state when the input is left unconnected (note: this feature operates with floating inputs, not terminated inputs). Like the half-duplex drivers, the three half-duplex receivers of the SP495 have independent Re- ceiver Enable control lines which are active LOW. A logic LOW on REx (pins 1, 4, or 5 of the SP495 ) enables the differential receivers. A logic HIGH on REx tri-states the receivers. The fourth receiver is controlled by its own RE4 Enable line and can be used in half-duplex or full-duplex modes.

SP495 Quad Differential RS-485 Transceiver © Copyright 2000 Sipex Corporation

ORDERING INFORMATION

Model Temperature Range Package For PLCC availability, please consult factory. Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others. Sipex Corporation Headquarters and Sales Office

22 Linnell Circle

Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: sales@sipex.com Sales Office

233 South Hillview Drive

Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600