DS275 Line-Powered RS-232 Transceiver Chip

The DS275 Line-Powered RS-232 Transceiver Chip is a CMOS device that provides a low-cost, very low-power interface to RS-232 serial ports. The receiver input translates RS-232 signal levels to common CMOS / TTL levels. The transmitter employs a unique circuit which steals current from the receive RS-232 signal when that signal is in a negative state (marking). Since most serial communication ports remain in a negative state statically, using the receive signal for negative power greatly reduces the DS275’s static power consumption.

This feature is especially important for battery-powered systems such as laptop computers, remote sensors, and calculators. During an actual communication session, the DS275’s transmitter will use system power (5-12 volts) for positive transitions while still employing the receive signal for negative transitions.

The DS275 is by Dallas Semiconductor is fully compatible with RS-232-E signals. Visit dalsemi.com for more information.

This topic is related to the followings HP Calculators: HP 39gs; HP 40gs; HP 48gII; HP 50g;