Out in Front: August 1, 1996

Incorporating five drivers and three receivers, the MAX3237 RS-232C transceiver from Maxim Integrated Products achieves transmission rates as high as 250 kbps in normal operation with a 3-k(ohm)/1000-pF load and 1 Mbps with a 3-k(ohm)/250-pF load. The IC includes dual charge pumps and a low-dropout output stage to produce true RS-232C levels from a single supply; these pumps require just four external 0.1-µF capacitors. Typical applications include serial ports for notebook and palmtop computers, high-speed modems, and battery-powered systems.

To maximize battery life yet maintain critical functionality, you can operate the MAX3237 in shutdown mode, in which it consumes just 1 µA, while all three receivers remain active. As a result, the device can monitor external devices but does not incur heavy current drain if power to the externally connected device is off. In fully active mode, the 3 to 5.5V IC typically consumes 500 µA. It is available in a 28-pin SSOP and costs $3.29 (1000).

—by Bill Schweber

Maxim Integrated Products, Sunnyvale, CA. (408) 737-7600, ext 6087, http://www.maxim-ic.com.