MAXIM Integrated Products, represented by Arrow Electronics , has introduced the MAX3322E/MAX3323E RS232 transceivers with switchable input impedance designed for use in multidrop RS232 applications.
The receiver input impedance can be a standard RS-232 5 kilohm load, or high impedance (>1 megohm).
The RS232 receiver is active in both cases, allowing multiple receivers to be connected at the same time without loading the line.
Additionally, the MAX3322E/MAX3323E feature enhanced electrostatic discharge (ESD) protection on the RS-232 inputs and outputs. The protection on these pins can withstand ±15kV using IEC 1000-4-2 Air-Gap Discharge Method, ±8kV using IEC 1000-4-2 Contact Discharge Method, and ±15kV using the Human Body Model.
The MAX3322E, a 2Tx/2Rx RS-232 transceiver, is ideal for applications requiring hardware handshaking, while the MAX3323E features 1Tx/1Rx for more integrated solutions. A proprietary low-dropout transmitter output stage enables RS-232-compatible performance over a +3.0V to +5.5V supply through a dual-charge pump. The MAX3322E/MAX3323E feature a 1 microamp shutdown mode in which the transmitter and receiver outputs are high impedance. These devices are guaranteed to run at data rates up to 250kbps, and the charge pump requires only four small 0.1 microfarad capacitors.
The MAX3322E/MAX3323E are offered in the extended (-40°C to +85°C) temperature range. The MAX3322E is available in a 20-pin TSSOP, and the MAX3323E is available in a space-saving 16-pin TSSOP or 16-pin DIP.