SLLSFR9A April 2024 – April 2024 THVD4411
PRODUCTION DATA
THVD4411 can be used in slow speed or fast speed RS-485 and RS-232 applications by configuring slew rate control (SLR) pin. Table 7-3 describes slew rate control function.
Signal state | Driver | Receiver | Comment |
---|---|---|---|
SLR = VIO | Maximum speed of operation for RS-485 = 500kbps. Maximum speed of operation in RS-232 mode is 250kbps | Maximum speed of operation for RS-485 = 500kbps. Maximum speed of operation in RS-232 mode is 250kbps | Active high slew rate limiting applied on driver output. In this configuration, glitch filter in receiver path for RS-485 is enabled |
SLR = GND or floating | Maximum speed of operation for RS-485= 20Mbps. Maximum speed of operation in RS-232 mode is 1Mbps | Maximum speed of operation for RS-485 = 20Mbps. Maximum speed of operation in RS-232 mode is 1Mbps | Slew rate limiting on driver output disabled. |
For RS-485 half and full duplex modes, receiver path in the slow speed mode (500kbps) provides additional noise filtering. To attenuate high frequency noise pulses from the bus which can be wrongly interpreted as valid data, SLR = VIO enables a low pass filter to filter out pulses with frequency higher than typical 800kHz.