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Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers
General Description
The HWD481, HWD483, HWD485, HWD487–HWD491, and HWD1487 are low-power transceivers for RS-485 and RS422 communication. Each part contains one driver and one receiver. The HWD483, HWD487, HWD488, and HWD489 feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, thus allowing error-free data transmission up to 250kbps. The driver slew rates of the HWD481, HWD485, HWD490, HWD491, and HWD1487 are not limited, allowing them to transmit up to 2.5Mbps. These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. Additionally, the HWD481, HWD483, and HWD487 have a low-current shutdown mode in which they consume only 0.1µA. All parts operate from a single 5V supply. Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit. The HWD487 and HWD1487 feature quarter-unit-load receiver input impedance, allowing up to 128 HWD487/ HWD1487 transceivers on the bus. Full-duplex communications are obtained using the HWD488–HWD491, while the HWD481, HWD483, HWD485, HWD487, and HWD1487 are designed for half-duplex applications.
__Next Generation Device Features
♦ For Fault-Tolerant Applications HWD3430: ±80V Fault-Protected, Fail-Safe, 1/4 Unit Load, +3.3V, RS-485 Transceiver HWD3440E–HWD3444E: ±15kV ESD-Protected, ±60V Fault-Protected, 10Mbps, Fail-Safe, RS-485/J1708 Transceivers ♦ For Space-Constrained Applications HWD3460–HWD3464: +5V, Fail-Safe, 20Mbps, Profibus RS-485/RS-422 Transceivers HWD3362: +3.3V, High-Speed, RS-485/RS-422 Transceiver in a SOT23 Package HWD3280E–HWD3284E: ±15kV ESD-Protected, 52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422, True Fail-Safe Receivers HWD3293/HWD3294/HWD3295: 20Mbps, +3.3V, SOT23, RS-855/RS-422 Transmitters ♦ For Multiple Transceiver Applications HWD3030E–HWD3033E: ±15kV ESD-Protected, +3.3V, Quad RS-422 Transmitters ♦ For Fail-Safe Applications HWD3080–HWD3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422 Transceivers ♦ For Low-Voltage Applications HWD3483E/HWD3485E/HWD3486E/HWD3488E/ HWD3490E/HWD3491E: +3.3V Powered, ±15kV ESD-Protected, 12Mbps, Slew-Rate-Limited, True RS-485/RS-422 Transceivers
Ordering Information appears at end of data sheet.
________________________Applications
Low-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level Translators Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks
______________________________________________________________Selection Table
PART NUMBER HWD481 HWD483 HWD485 HWD487 HWD488 HWD489 HWD490 HWD491 HWD1487 HALF/FULL DUPLEX Half Half Half Half Full Full Full Full Half DATA RATE (Mbps.