Analog Devices Inc./Maxim Integrated

The LTC2856-1, LTC2856-2, LTC2857-1, LTC2857-2, LTC2858-1 and LTC2858-2 are low power, RS485/RS422 transceivers operating on 5V supplies at maximum data rates of 20Mbps or 250kbps for low EMI. The receiver has a one-eighth unit load, supporting up to 256 nodes per bus (C, I-Grade), and a fail-safe feature that guarantees a high output state under conditions of floating or shorted inputs.The driver maintains a high output impedance over the entire common mode range when disabled or when the supply is removed. Excessive power dissipation caused by bus contention or a fault is prevented by current limiting all outputs and by thermal shutdown.Enhanced ESD protection allows these parts to withstand ±15kV (human body model) on the transceiver interface pins without latch-up or damage.Part NumberMAX Data Rate (Mbps)DuplexPackageLTC2856-120HalfMSOP-8, DFN-8LTC2856-20.25HalfMSOP-8, DFN-8LTC2857-120FullMSOP-8, DFN-8LTC2857-20.25FullMSOP-8, DFN-8LTC2858-120FullMSOP-10, DFN-10LTC2858-20.25FullMSOP-10, DFN-10ApplicationsLow Power RS485/RS422 TransceiverLevel TranslatorBackplane Transceiver

The LTC2859 and LTC2861 are low power, 20Mbps RS485/422 transceivers operating on 5V supplies. The receiver includes a logic-selectable 120Ω termination, one-eighth unit load supporting up to 256 nodes per bus, and a fail-safe feature that guarantees a high output state under conditions of floating or shorted inputs.The driver features a logic-selectable low-EMI 250kbps operating mode, and maintains a high output impedance over the entire common mode range when disabled or when the supply is removed. Excessive power dissipation caused by bus contention or a fault is prevented by current limiting all outputs and by a thermal shutdown.Enhanced ESD protection allows the LTC2859 and LTC2861 to withstand ±15kV (human body model) on the transceiver interface pins without latch-up or damage.ApplicationsLow Power RS485/RS422 TransceiverLevel TranslatorBackplane Transceiver

The LTC2862/LTC2863/LTC2864/LTC2865 are low power, 20Mbps or 250kbps RS485/RS422 transceivers operating on 3V to 5.5V supplies that feature ±60V overvoltage fault protection on the data transmission lines during all modes of operation, including power-down. Low EMI slew rate limited data transmission is available in a logic-selectable 250kbps mode in the LTC2865 and in 250kbps versions of the LTC2862-LTC2864. Enhanced ESD protection allows these parts to withstand ±15kV HBM on the transceiver interface pins without latch-up or damage.Extended ±25V input common mode range and full fail-safe operation improve data communication reliability in electrically noisy environments and in the presence of large ground loop voltages.Part NumberDuplexEnablesMax Data RateVLPinLTC2862-1HalfYes20MNoLTC2862-2HalfYes250kNoLTC2863-1FullNo20MNoLTC2863-2FullNo250kNoLTC2864-1FullYes20MNoLTC2864-2FullYes250kNoLTC2865FullYes20M/250kYesApplicationsSupervisory Control and Data Acquisition (SCADA)Industrial Control and Instrumentation NetworksAutomotive and Transportation ElectronicsBuilding Automation, Security Systems and HVACMedical EquipmentLighting and Sound System Control

The LTC2862A is a low power, 20Mbps or 250kbps RS485/RS422 transceiver operating on 3V to 5.5V supplies with ±60V overvoltage fault protection on the interface pins during all modes of operation, including power-down. Improvements were made to the LTC2862 for greater robustness and signal integrity: ±40kV HBM and Level 4 IEC ESD protection on the interface pins; increased resistance to electrical overstress; increased receiver noise immunity; additional receiver noise filtering on the LTC2862A-2; and an improved failsafe function optimized for high speed in the LTC2862A-1 and noise rejection in the LTC2862A-2. Low EMI slew rate limited data transmission is available in the 250kbps LTC2862A-2 option, while the LTC2862A-1 operates to 20Mbps.Extended ±25V input common mode range and full failsafe operation improve data communication reliability in electrically noisy environments and in the presence of large ground loop voltages.APPLICATIONSSupervisory Control and Data Acquisition (SCADA)Industrial Control and Instrumentation NetworksAutomotive and Transportation ElectronicsBuilding Automation, Security Systems and HVACMedical EquipmentLighting and Sound System Control

The LTC2870/LTC2871 are robust pin-configurable multiprotocol transceivers, supporting RS232, RS485, and RS422 protocols, operating on a single 3V to 5.5V supply. The LTC2870 can be configured as two RS232 single-ended transceivers or one RS485 differential transceiver on shared I/O lines. The LTC2871 offers independent control of two RS232 transceivers and one RS485 transceiver, each on dedicated I/O lines.Pin-controlled integrated termination resistors allow for easy interface reconfiguration, eliminating external resistors and control relays. Half-duplex switches allow four-wire and two-wire RS485 configurations. Loopback mode steers the driver inputs to the receiver outputs for diagnostic self-test.The RS485 receivers support up to 256 nodes per bus, and feature full failsafe operation for floating, shorted or terminated inputs.An integrated DC/DC boost converter uses a tiny 2mm × 1.6mm inductor and one capacitor, eliminating the need for multiple supplies for driving RS232 levels.ApplicationsFlexible RS232/RS485/RS422 InterfaceSoftware Selectable Multiprotocol Interface PortsPoint-of-Sale TerminalsCable RepeatersProtocol Translators