The S13 is a general purpose RS232 level shifter intended for use in connecting low voltage TTL or CMOS (3.3.V or 5V) devices like microcontrollers to standard RS232 serial ports on PCs or other similar systems.
The CTS and RTS lines are connected and exposed, though not used by the 4-pin BrainStem connector. These can be wired separately for other uses in your application.
The S13 RS232 level shifter is powered by the low voltage UART side. While specified to operate between 3.0V and 5.0V, our testing shows it to work down to ~2.5V, though we don't guarantee full data rates and RS232 levels. Please confirm signal integrity in your system if you are using a lower supply level. An internal charge pump generates positive and negative rails for the RS232 side of the shifter. The table below shows the RS232 voltages and current consumption for a range of low voltage rail. All RS232 voltages are within the RS232 specification. Current consumption measurements are for reference only and may vary significantly from device to device. Average loads are for low rate continuous 1/0 transmission at 50% duty-cycle.
The S13 is qualified for baudrate of atleast 250kbps. Higher data rate may be possible but will depend on actual supply voltage levels and signal integrity of the TTL UART and RS232 system.