RS-485 Reference Design Delivers Added Output Power

Operating with an input-voltage range from 3.3V to 5V, the company's 2.5-Mb/s, isolated RS485 reference design provides an interface capable of delivering up to 500 mW of supplementary output power. The additional power can drive external loads such as transceiver nodes, a/d converters, point-of-sale card readers, and RFID scanners. The design enlists the company's PS9821 optocouplers and National Semiconductor's LMS1487 differential bus transceiver. The optocouplers provide isolation and data rates up to 15 Mb/s over the full input-voltage range. In an eight-pin SOIC package, the transceiver operates at speeds up to 2.5 Mb/s with full ANSI, RS485A, and RS422-B compliance. CALIFORNIA EASTERN LABORATORIES, Santa Clara, CA. (408) 988-3500.