Transceivers Convert RS-232 Port To Multidrop Network

Designed for use in multidrop RS-232 applications, the MAX3322E and MAX3323E transceivers feature a switchable input impedance, with the impedance capable of being an RS-232, 5-k? load or a high-impedance input greater than 1 M?. At either setting, the RS-232 receiver is active, allowing multiple receivers to be connected at the same time without loading the line. Both devices provide enhanced ESD protection on the RS-232 I/Os of up to ±15 kV using the IEC 1000-4-2 air-gap discharge method, ±8 kV via the IEC 1000-4-2 contact-discharge method, and up to ±15 kV using the human body model. The MAX3322E 2Tx/2Rx RS-232 transceiver targets applications requiring hardware handshaking, while MAX3323E provides 1Tx/1Rx for more integrated environments. Other shared features include 3V to 5.5V operation and data rates up to 250 Kb/s. The transceivers' charge pumps require four 0.1 µF capacitors for operation. MAX3322E comes in 20-pin TSSOPs and MAX3323E in 16-pin TSSOPs or DIP.s Prices start at $2.90 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.