Features and Benefits
- High Input Impedance: Up to 256 Transceivers on the Bus
- Low Power: ICC = 120µA Max with Driver Disabled
- ICC = 200µA Max with Driver Enabled, No Load
- 1µA Quiescent Current in Shutdown Mode
- Controlled Slew Rate Driver for Reduced EMI
- Single 5V Supply
- ESD Protection to ±10kV On Receiver Inputs and Driver outputs
- -7V to 12V Common-Mode Range Permits ±7V Ground Difference Between Devices on the Data Line
- Thermal Shutdown Protection
- Power Up/Down Glitch-Free Driver Outputs Permit Live Insertion or Removal of Transceiver
- Driver Maintains High Impedance in Three-State or with the Power Off
- Pin Compatible with the LTC485
The LTC1487 is an ultra-low power differential line transceiver designed with high impedance inputs allowing up to 256 transceivers to share a single bus. It meets the requirements of RS485 and RS422. The LTC1487 features output drivers with controlled slew rate, decreasing the EMI radiated from the RS485 lines, and improving signal fidelity with misterminated lines. The CMOS design offers significant power savings without sacrificing ruggedness against overload or ESD damage. Typical quiescent current is only 80µA while operating and 1µA in shutdown.
The driver and receiver feature three-state outputs, with the driver outputs maintaining high impedance over the entire common-mode range. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shutdown circuit which forces the driver outputs into a high impedance state. The receiver has a fail-safe feature which guarantees a high output state when the iputs are left open. I/O pins are protected against multiple ESD strikes of over ±10kV using the Human Body Model. The LTC1487 is fully specified over the commercial temperature range and is available in 8-pin DIP and SO packages.
- Battery-Powered RS485/RS422 Applications
- Low Power RS485/RS422 Transceiver
- Level Translator
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-RS485HDEBZ allows quick and easy evaluation of half-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), receiver output (RO), driver enable (DE) and receiver output (RO). Bus signals A and B (half-duplex bus) can be connected to a bus screw terminal block. One or two termination resistors can be connected to A and B via jumper settings, in order to evaluation the half-duplex RS-485 driver and receiver. Footprints are provided for pull-up and pull-down (biasing resistors) on the bus.
Devices for evaluation on the board must be ordered separately.
LTC1487 Companion Parts
Recommended Related Parts
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.