ZHCSSR6B August 2023 – April 2024 THVD4431
PRODUCTION DATA
The THVD4431 bus pins are protected against any DC supply shorts in the range of -16 V to +16 V. In the RS-485 mode, the short circuit current is limited to ±250 mA to comply with the TIA/EIA-485A standard. In RS-232 mode, current limiting of ±60 mA is applicable for scenarios where bus pins can short to ground.
The device also features thermal shutdown protection that disables the driver and the receiver if the junction temperature exceeds the TSHDN threshold due to excessive power dissipation on-chip.
Supply undervoltage protection is present on both VCC and VIO supplies. This maintains the bus output and receiver logic output in known driven state when both the supplies are above their rising undervoltage thresholds. Table below describes the device behavior in various scenarios of supply levels.
| VCC | VIO | Driver Output | Receiver Output |
|---|---|---|---|
| > UVVCC(rising) | > UVVIO(rising) | For RS-485 mode, determined by DIR and L3 inputs. For RS-232 mode, determined by L3, L4, L6 inputs. For shutdown mode, Hi-Z | For RS-485 mode, determined by DIR and (R1-R2) or (R3-R4) inputs. For RS-232 mode, determined by R1, R2, R5, R7, R8 inputs. For shutdown mode, Hi-Z |
| < UVVCC(falling) | > UVVIO(rising) | High impedance | Undetermined |
| > UVVCC(rising) | < UVVIO(falling) | High impedance | High impedance |
| < UVVCC(falling) | < UVVIO(falling) | High impedance | High impedance |