STR485LVQT STMicroelectronics

STR485 Datasheet 3.3 V RS485 compatible with 1.8 V I/Os and selectable speed 20 Mbps or 250 kbps Features Half-duplex RS485 transceiver 1.65 V to 3.6 V supply for data and enable signals 3 V to 3.6 V supply for bus supply DFN10 3 x 3 High speed: up to 20 Mbps data rate Low speed selected by SLR pin : 250 kbps Up to 256 transceivers on the bus Fail safe receiver (bus open, idle and shorted) Thermal shutdown protection Low quiescent current in shutdown mode Extended temperature range : -40 C to +105 C Available in industry standard DFN10 Bus-pin protection more than: 4 kV HBM protection 8 kV IEC61000-4-2 contact discharge 16 kV IEC61000-4-2 air discharge Compliant IEC61000-4-4 fast transient burst Class B Description The STR485 is a low power differential line transceiver for data transmission Product status link standard RS485 applications in half-duplex mode. Data and enable signals are STR485 compatible with 1.8 V or 3.3 V supplies. Two speeds are selectable through SLR pin: fast data rate up to 20 Mbps or slow data rate for extended cable running to 250 kbps. Excessive power dissipation caused by bus contention or faults is prevented by thermal shutdown circuit that forces the driver outputs into a high impedance state. The receiver has a fail-safe feature, which guarantees a high output state when the inputs are left open, shorted or idle. DS12713 - Rev 5 - July 2020 www.st.com For further information contact your local STMicroelectronics sales office.STR485 Pin connections 1 Pin connections Figure 1. Pin connections V V L CC R B DE A RE SLR GND D Table 1. Pin description Name Pin I/O Description VL 1 Logic supply 1.65 V to 3.6 V supply for logic I/O signals R 2 Digital output Receiver data output Driver enable input: DE 3 Digital input serial resistors of 150 ohms followed by 2.5 Mohms/GND Receiver enable input: nRE 4 Digital input serial resistors of 150 ohms followed by 2.5 Mohms/VCC D 5 Digital input Transmission data input GND 6 Ground Slew rate select: low = 20 Mbps, high = 250 kbps. SLR 7 Digital input Default to 20 Mbps if SLR is left floating A 8 Bus I/O Digital bus I/O, A B 9 Bus I/O Digital bus I/O, B VCC 10 Bus supply 3 V to 3.6 V supply for A and B bus lines DS12713 - Rev 5 page 2/26