Features and Benefits
- Complies with ANSI TIA/EIA-485-A-1998 and ISO 8482: 1987(E)
- 250 kbps data rate
- Single 5 V ± 10% supply
- −7 V to +12 V bus common-mode range
- Connect up to 32 nodes on the bus
- Reduced slew rate for low EM interference
- Short-circuit protection
- 30 μA supply current
Product DetailsThe ADM488A and ADM489A are low power, differential line transceivers suitable for communication on multipoint bus transmission lines. They are intended for balanced data transmission and comply with both RS-485 and RS-422 standards of the Electronics Industries Association (EIA). Both products contain a single differential line driver and a single differential line receiver, making them suitable for full-duplex data transfer. The ADM489A contains an additional receiver and driver enable control.
The input impedance is 12 kΩ, allowing 32 transceivers to be connected on the bus. The ADM488A/ADM489A operate from a single 5 V ± 10% power supply.
Excessive power dissipation that is caused by bus contention or output shorting is prevented by a thermal shutdown circuit. This feature forces the driver output into a high impedance state if, during fault conditions, a significant temperature increase is detected in the internal driver circuitry. The receiver contains a fail-safe feature that results in a logic high output state if the inputs are unconnected (floating).
The ADM488A/ADM489A are fabricated on BiCMOS, an advanced mixed technology process combining low power CMOS with fast switching bipolar technology.
The ADM488A/ADM489A are fully specified over the industrial temperature range and are available in SOIC and MSOP packages.Applications
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
The EVAL-RS485FD8EBZ allows quick and easy evaluation of full-duplex RS-485 transceivers with standard 8-lead SOIC footprints. The evaluation board allows interfacing via screw terminal block to digital I/O for driver input (DI) and receiver output (RO). Bus signals A, B, Y and Z (full-duplex bus) can be connected to a bus screw terminal block. Termination resistors are fitted across A and B, as well as Y and Z. These can be connected in half-duplex configuration (A to Y, B to Z), in order to evaluate the RS-485 driver. Footprints are provided for pull-up and pull-down (biasing resistors) on the receiver inputs in order to provide the option to evaluate an RS-485 receiver with this configuration.
Devices for evaluation on the board must be ordered separately.
Product Selection Guide (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.