ISL81485 Data Sheet July 2004 FN6061.1 5V, 30Mbps, RS-485/RS-422 Transceiver Features The Intersil ISL81485 is a BiCMOS, 5V powered, single Specified for 10% Tolerance Supplies transceiver that meets both the RS-485 and RS-422 High Data Rates . up to 30Mbps standards for balanced communication, and features a larger Large Differential Output Voltage 2.0V(min.) into 54 output voltage and higher data rate to benefit high speed applications. Drop-In Replacement for the ADM1485 Unlike competitive devices, this Intersil transceiver is One Unit Load Allows up to 32 Devices on the Bus specified for 10% tolerance supplies (4.5V to 5.5V), and it A Low Quiescent Current . 800 delivers a much larger worst case differential output voltage (2.0V compared to the typical 1.5V) over the full supply -7V to +12V Common Mode Input Voltage Range range. The increased output voltage translates into longer Three State Rx and Tx Outputs reach, or better data integrity, at the 30Mbps data rate. 15ns (Max) Propagation Delays, 5ns (Max) Skew This device presents a 1 unit load to the RS-485 bus, which Operates from a Single +5V Supply (10% Tolerance) allows up to 32 transceivers on the network. Current Limiting and Thermal Shutdown for driver Receiver (Rx) inputs feature a fail-safe if open design, Overload Protection which ensures a logic high Rx output if Rx inputs are floating. Pb-free available Driver (Tx) outputs are short circuit protected, even for Applications voltages exceeding the power supply voltage. Additionally, SCSI Fast 20 Drivers and Receivers on-chip thermal shutdown circuitry disables the Tx outputs to prevent damage if power dissipation becomes excessive. Factory Automation Field Bus Networks Ordering Information Security Networks PART NO. TEMP. PKG. o (BRAND) RANGE ( C) PACKAGE DWG. Building Environmental Control Systems ISL81485IB -40 to 85 8 Ld SOIC M8.15 Industrial/Process Control Networks (81485IB) ISL81485IBZ -40 to 85 8 Ld SOIC M8.15 Pinout (81485IB) (See Note) (Pb-free) ISL81485 (SOIC, MSOP) ISL81485IU (1485) -40 to 85 8 Ld MSOP M8.118 TOP VIEW ISL81485IUZ (1485) -40 to 85 8 Ld MSOP M8.118 (See Note) (Pb-free) RO 1 8 V CC R *Add -T suffix to part number for tape and reel packaging. RE 2 7 B / Z NOTE: Intersil Pb-free products employ special Pb-free material DE 3 6 A / Y sets molding compounds/die attach materials and 100% matte tin D DI 4 5 GND plate termination finish, which is compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J Std-020B. CAUTION: These devices are sensitive to electrostatic discharge follow proper IC Handling Procedures. 1 1-888-INTERSIL or 321-724-7143 Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2003, 2004. All Rights Reserved All other trademarks mentioned are the property of their respective owners.ISL81485 Truth Table Truth Table TRANSMITTING RECEIVING INPUTS OUTPUTS INPUTS OUTPUT RE DE DI B / Z A / Y RE DE A-B RO X 1101 00 +0.2V 1 X 1010 00 -0.2V 0 X 0 X High-Z High-Z 0 0 Inputs Open 1 1 X X High-Z Pin Descriptions PIN FUNCTION RO Receiver output: If A > B by at least 0.2V, RO is high If A < B by 0.2V or more, RO is low RO = High if A and B are unconnected (floating). RE Receiver output enable. RO is enabled when RE is low RO is high impedance when RE is high. DE Driver output enable. The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when DE is low. DI Driver input. A low on DI forces output Y low and output Z high. Similarly, a high on DI forces output Y high and output Z low. GND Ground connection. A/Y RS-485/422 level, noninverting receiver input and noninverting driver output. Pin is an input (A) if DE = 0 pin is an output (Y) if DE = 1. B/Z RS-485/422 level, inverting receiver input and inverting driver output. Pin is an input (B) if DE = 0 pin is an output (Z) if DE = 1. V System power supply input (4.5V to 5.5V). CC Typical Operating Circuit ISL81485 +5v +5v + + 0.1 F 0.1 F 8 8 V V CC CC 1 RO 4 DI R D 2 RE R R 3 7 T 7 B / Z DE B / Z T 6 A / Y 3 DE A / Y 6 2 RE 4 DI RO 1 R D GND GND 5 5 2